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PRE-PUBLICATION DRAFTâUnedited Text and Graphics Chapter 6 â Investigation of Luminaire Pole and PSST Crash Tests and Simulations As described in the previous chapters, a total of two full-scale crash tests were conducted on steel luminaire poles supported on the TB1-17 transformer base, while five tests were carried out on 2¼-in. x 2¼-in. 12-gauge PSST posts. After the crash testing, the LS-DYNA simulations were validated using the test data, leading to significant improvements in the accuracy of predicting the impact behavior of these devices. However, the validation process is incomplete without running the full set of tests. For instance, the simulations for luminaire poles representing MASH test nos. 3-61 and 3-62 impact conditions lack full-scale crash test data for validation, and the outcomes for the PSST post testing were not consistent, which makes it challenging to develop guidelines and recommend modifications to MASH for these systems. Thus, the concept of identifying a family and utilizing a reduced test matrix to determine crashworthiness could not be fully demonstrated. However, despite these challenges, the research team closely analyzed all available crash test data along with the simulation results. This thorough examination allowed for a better understanding of the performance and behavior of the tested devices under various impact conditions. The information serves as a foundation for future research and potential improvements in the development of guidelines and MASH modifications. Furthermore, with the implementation of the improved simulations of the luminaire pole, the research team conducted a re-run of simulations on the revised cases to update the observations and conclusions from Phase II. During Phase II, the simulations were validated against a few crash tests (i.e., FOIL crash test nos. 21011 and 21017 as well as two pendulum tests). However, the newly validated simulations enhanced the accuracy of the predictions. This approach helped identify configurations and impact conditions that were more critical. By incorporating validated simulations, the study offers more reliable insights and understanding of the crashworthiness of these devices. 6.1 Analysis of Luminaire Poles Supported by TB1-17 Transformer Base 6.1.1. Full-Scale Crash Testing â Luminaire Poles All available crash test data were collected from FOIL, MwRSF, and TTI and listed in Table 32. MwRSF crash tests, test nos. TBLP-1 and TBLP-2, were detailed in Chapter 2 of the current report. FOIL pendulum tests, test nos. 20009A and 20009B, as well as FOIL crash test nos. 21011 and 21017 were detailed in Interim Report No. 2 and briefly described in Section 3.5 and 3.6 of the current report, respectively. Recently, two full-scale crash tests were conducted on steel luminaire poles with a TB1-17 transformer base according to MASH test no. 3-60 impact conditions at TTI. Note that the test report has not been published and the research is not yet complete. The TTI crash test data was shared with the NCHRP Project 22-43 research team with the permission of the Texas Department of Transportation for comparison of pole behaviors in similar impact conditions. For more details on the TTI crash tests and research effort, inquiries can be directed to the TTI research team. Figures 143 through 150 include images from testing performed under Project 0-6968 used with permission from TTI and the Texas Department of Transportation. 178 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 32. List of Available MASH Crash Tests on a Steel Luminaire Pole with the TB1-17 Transformer Base Mast Pole Pole Total Roof Test Testing Type of Single/Dual Arm Longitudinal Longitudinal Designation Height Thickness Weight Crush Pass/Fail Name Facility Test Arm Length OIV (ft/s) ORA (g) (ft) (in.) (lb) (in.) (ft) Pendulum 20009A FOIL N/A 25 Single 8 11 ga. 280 N/A 10.45 N/A N/A Test Pendulum 20009B FOIL N/A 50 Dual 10 0.13 in. 668 N/A 11.2 N/A N/A Test 21011 FOIL Full-Scale MASH 3-60 35 Dual 20 11 ga. 815 13.5 0.91 1.1 PASS 21017 FOIL Full-Scale MASH 3-60 25 Dual 20 11 ga. 781 11.8 1 2.7 PASS TBLP-1 MwRSF Full-Scale MASH 3-60 50 Dual 15 7 ga. 1,015 17.8 1.2 0.2 FAIL TBLP-2 MwRSF Full-Scale MASH 3-60 30 Single 30 7 ga. 824 31.7 1.6 0 FAIL 440862 Within TTI Full-Scale MASH 3-60 50 Dual 10 11 ga. 730 12.1 6 FAIL -01-1 MASH Limit 440862 Within TTI Full-Scale MASH 3-60 40 Dual 10 11 ga. 553 22.6 5.8 FAIL -01-2 MASH Limit 179 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics In the first TTI test, test no. 440862-01-1, a 50-ft tall pole with dual 10-ft long mast arms was impacted by a small car (1100C) under MASH test no. 3-60 impact conditions with a vehicle center impact point, as shown in Figure 143. The total system weight was 730 lb. Upon impact, the transformer base activated and fractured. The pole fell on the vehicleâs roof and caused a maximum roof crush of 6 in. toward the middle of the roof, which exceeded the MASH limit of 4 in., as shown in Figure 144. The rear window was also shattered. The vehicle damage and the sequential photographs are shown in Figures 145 and 146, respectively. Figure 143. Pole Crash Test Setup â TTI Test No. 440862-01-1 [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] Figure 144. Post-Test Photograph â TTI Test No. 440862-01-1 [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] 180 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Figure 145. Vehicle Damage â TTI Test No. 440862-01-1 [Testing performed under Project 0- 6968 used with permission from TTI and TxDOT] 181 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Figure 146. Sequential Photographs, TTI Test No. 440862-01-1 (timesteps for sequential images were not available) [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] 182 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics TTI test no. 440862-01-1 was similar to the system tested in MwRSF test no. TBLP-1, except the arm length and the total system weight. In the TTI test, the dual mast arms measured 10 ft, while the MwRSF system had longer dual mast arms, extending to 15 ft. Additionally, the pole used in the TTI test had an 11-gauge wall thickness, resulting in a total weight of 730 lb. The MwRSF pole had a 7-gauge wall thickness to reach the maximum weight limit of 1,000 lb, leading to a total weight of 1,015 lb. Both the MwRSF test and the TTI test failed to meet MASH criteria but showed distinct behaviors. In the MwRSF test, the base fractured, causing the pole to fall on the vehicleâs roof edge, resulting in a roof crush well below the MASH limit. However, the longitudinal OIV of 17.8 ft/s exceeded the MASH limit of 16 ft/s. Conversely, in the TTI test, the pole fell on the middle of the vehicleâs roof, causing a roof crush of 6 in. which exceeded the 4 in. MASH limit. Further, the longitudinal OIV in the TTI test measured 12.1 ft/s, which was within the MASH limit. The inconsistent behavior of the poles after base fracture caused challenges in predicting roof crush through simulation. Furthermore, inaccuracy in the vehicle roof model added more complexity to the problem. Vehicle roof models used in simulations might not always provide precise predictions of roof crush when subjected to pole impact events. These challenges will be investigated in the continuation of the current project. On a positive note, the simulations that were validated against MwRSF and FOIL tests could effectively predict the OIV as one of the two failing concerns. Recently, the TTI test data became available to the research team, and these tests will be simulated to assess the capability of LS-DYNA models in predicting OIV using the TTI test results. The second TTI test, test no. 440862-01-2, utilized a 40-ft tall pole with dual 10-ft long mast arms and was impacted by a small car (1100C) under MASH test no. 3-60 impact conditions with a vehicle center impact point, as shown in Figure 147. The total system weight was 553 lb. Upon impact, the transformer base activated and fractured. But the pole was standing stationary in front of the vehicle, then rolled across the top of the vehicle, resulting in a maximum roof crush of 5.8 in. (>4-in. MASH limit), as shown in Figure 148. The longitudinal OIV was 22.6 ft/s (>16-ft/s MASH limit). The test failed two MASH safety performance criteria. The vehicle damage and the sequential photographs are shown in Figures 149 and 150, respectively. TTI test no. 440862-01-2 provided additional unexpected outcomes. This test involved a system comparable to that examined in FOIL test no. 21011. In the TTI test, a 40-ft tall pole with 10-ft long dual mast arms was used, while the FOIL test used a 35-ft tall pole with longer dual mast arms extending to 20 ft. The total weights of the tested systems were 553 lb and 815 lb for TTI and FOIL, respectively. Unexpectedly, the TTI test failed to meet MASH criteria for both roof crush and OIV, while the FOIL system, with a larger weight and longer mast arms, passed all MASH criteria. This outcome can be due to the inherent variability in base fracture behavior and the inconsistencies in pole response during impacts. These outcomes challenge the historical belief that heavier poles cause more severe damage and demonstrates that shorter or lighter poles may also lead to test failures. Given these observations, the research team would require conducting an in-depth analysis and running a comprehensive series of crash tests prior to making recommendations for reducing testing matrices for this luminaire pole family of devices. To provide more informed recommendations, the research team needs to further investigate a wide range of poles and crash 183 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics scenarios for luminaire poles with the TB-17 transformer base through full-scale crash testing and the validated LS-DYNA models. The continuation project (i.e., NCHRP Project 17-105) can contribute to this objective to some extent by offering more full-scale crash tests and validated simulations. Figure 147. Pole Crash Test Setup â TTI Test No. 440862-01-2 [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] Figure 148. Post-Test Photograph â TTI Test No. 440862-01-2 [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] 184 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Figure 149. Vehicle Damage â TTI Test No. 440862-01-2 [Testing performed under Project 0- 6968 used with permission from TTI and TxDOT] 185 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Figure 150. Sequential Photographs, TTI Test No. 440862-01-2 (Timesteps for sequential images were not available) [Testing performed under Project 0-6968 used with permission from TTI and TxDOT] 186 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics 6.1.2. Updated Computer Simulation â Luminaire Poles As described in Chapter 3, the LS-DYNA model of the transformer base TB1-17 was revised using data obtained from several full-scale crash tests, material certifications, and precise measurements of the base. Subsequently, the updated base model was integrated into the luminaire pole models, and simulations were then rerun to reflect these changes. The selected pole-arm configurations are listed in Table 33, which has additional pole configurations compared to the originally developed list in Phase II. Note that in this table, âSâ stands for single mast arm, and âDâ stands for dual mast arms. In the initial selection of poles, the criteria were set to identify the most extreme cases. These cases included heaviest pole with a specific height, which in turn would have the maximum pole wall thickness (i.e., 11 gauge for 20-ft tall poles, 7 gauge for 30- and 40-ft tall poles, and 3 gauge for 50-ft tall poles). In this Phase, thinner poles were added to the selected pole list for simulations, as the mass distribution significantly influenced the overall behavior of the poles in terms of breakaway behavior, roof crush, and OIV. Also, the variability in pole behavior required more data points for drawing more robust recommendations. In this round of simulation with the updated transformer base, the previously selected pole configurations with 30 and 40 ft heights were subjected to simulations involving two different pole wall thicknesses (i.e., 11 gauge and 7 gauge). For 50-ft-tall poles, simulations were conducted with three pole wall thicknesses: 10 gauge; 7 gauge; and 3 gauge. Simulations were carried out for poles weighing from 250 to approximately 1,200 lb. Moreover, two additional cases, labeled as Case Nos. 78 and 79, were introduced into the numerical study. Both cases involve 30-ft tall poles with different mast arm configurations. Case No. 78 is a 30-ft tall pole with a single 20-ft long mast arm, while Case No. 79 is a 30-ft tall pole with dual 20-ft long mast arms. These newly introduced cases were added to investigate the behavior of 30-ft tall pole with shorter mast arms (20 ft mast arm as compared to Case no. 27 with 30-ft mast arm which failed MASH 3-60 in test no. TBLP-2). In the end, the total number of pole configurations was expanded from the previous count of 20 to a total of 39, as shown in Table 33. For majority of the pole configurations, similar to the first-round simulations (i.e., preliminary simulations prior to crash testing), the pole configurations were simulated under MASH test nos. 3-60, 3-61, and 3-62 conditions at impact angles of 0 and 25 degrees and impacting the left-quarter, center, and right-quarter points of the vehicle. For efficiency purposes, the pole configurations with maximum wall thicknesses and thus higher weights were exclusively simulated under critical impact conditions (i.e., vehicle center impact point and 0-degree impact angle for MASH 3-60, MASH 3-61, and MASH 3-62 impact conditions). For instance, the 50-ft tall poles (i.e., pole Case Nos. 48, 101, 53, and 106) with 10-gauge pole wall thickness were simulated across all 18 MASH impact conditions, while other wall thicknesses, such as 7 and 3 gauge (which are less common) were exclusively simulated for the critical conditions. 187 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 33. Updated List of Pole Configurations for Re-Running LS-DYNA Simulations Pole Arm and Mass at CG Mast Arm Mast Thickness Pole Weight Weight Sim. No. Height Connection Ends Height Length (ft) Config. (in.) (lb) (lb) (ft) (lb) (lb) (ft) 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 27-7ga 30 30 S 0.1880 500.0 212.0 75 787 24.30 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 188 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Recall that the orientations are such that an impacting vehicle would be leaving the roadway and impacting the luminaire support located on the left side of the road. In other words, the left-quarter point corresponds to the nearest point to the pole, and the right-quarter point corresponds to the farthest point to the pole. Moreover, in the simulations, a 75-lb mass was added to the end of the mast arm to simulate the luminaire weight. In accordance with the panelâs suggestion, as the numerical effort continues (in the continuation of the current project, i.e., NCHRP 17-105), the 75-lb mass will be modified to 50 lb. However, in comparison with the results obtained from the previous simulations, the simulations maintained the 75-lb mass. The simulations for the pole configurations were post-processed and their results were analyzed to identify possible trends regarding the MASH safety criteria, including occupant compartment deformation, occupant risk measures (i.e., lateral, and longitudinal OIV and ORA) and vehicle instability (i.e., roll and pitch angles). Occupant Compartment Deformation A summary of the simulated maximum occupant compartment deformation for MASH 3-60 is listed in Table 34. For the MASH 3-61 and MASH 3-62 impacts, the simulated maximum occupant compartment deformation is listed in Table 35. The âN/Aâ designation indicates that pole did not contact any part of the vehicle. The letters âW,â âA,â âB,â and âCâ appearing in front the values indicate the specific area of the vehicle where the maximum deformation occurred. As such, âWâ stands for the windshield area, âAâ denotes A-pillar, and âBâ and âCâ stand for B-pillar and C- pillar, respectively. The âNBâ designation denotes that the transformer base did not break away, thus no pole-vehicle contact was expected. In these tables, the expected potential to pass the MASH safety criteria for each pole configuration is shown. A cell that indicates a medium potential to pass the MASH criteria, meaning that at least one measure of the safety criteria exceeded the preferred limit in MASH or resulted in a concerning value if no preferred limit exists. For occupant compartment deformation, any deformation due to the luminaire pole contacting the vehicleâs roof was considered to have medium potential to pass MASH criteria due to the high variability of luminaire pole behavior. This conservative approach was taken due to the current uncertainty in the modelsâ accuracy in predicting vehicle deformation. If the deformation exceeded the MASH limit of 4 in. the cell was highlighted, indicating low potential of passing MASH. Note that the blank cells (where no values are present) indicate that a simulation was not conducted for that specific impact condition and does not imply a high likelihood of passing MASH. Several trends were identified from analysis of the simulation results in terms of occupant compartment deformation (generally referred to as roof crush, windshield, or rear window crush). Similar to first round of simulation in Phase II, the simulation results (using the revised base model after full-scale crash tests) proved that MASH test no. 3-60 tended to be more critical than test nos. 3-61 and 3-62 due to the larger roof crush observed when the luminaire pole fell on top of the vehicle moving at a low speed. For majority of cases, center impacts were identified as more critical than right- or left-quarter point impacts in terms of roof crush. This finding was due to the propensity for the pole to fall longitudinally and land directly on the vehicle instead of being pushed to the side of the vehicle 189 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics during quarter-point impacts. The center of the vehicleâs roof also tended to be less stiff as compared to the roof sides, which resulted in larger roof deformations under pole impacts. While there were instances where a 25-degree impact angle resulted in increased roof crush as compared to 0-degree impact angle (e.g., Case Nos. 54-11ga, 72-7ga, 40-11ga, 41-11ga, 48-10ga), the general trend indicated that a center impact point was more likely to lead to pole contact with the center of the roof, thereby causing higher roof crush. In the case of one particular outlier, namely Case No. 54-11ga (involving a 20-ft tall pole with dual 4-ft long mast arms), the MASH 3-60 impact with a center impact point at a 25-degree impact angle showed significantly higher roof crush (6.7 in.) compared to the 0-degree impact scenario (2.6 in.). This finding may be attributed to uncertainties associated with the nature of base fracture. In the 25-degree impact, the pole made contact with the center of the vehicle roof, as shown in Figure 151. While acknowledging that such behavior may be a rare occurrence in physical crash tests, the general trend still proves that a 0-degree impact with a center impact point tended to result in more substantial roof crush, recommending this impact scenario for evaluating roof crush. For a better comparison, the simulated roof crush data was ordered based on the total system weight. Excluding the outlier Case 54-11ga (center impact point with a 25-degree impact angle), it showed that the simulated roof crush raises concerns for poles weighing more than 500 lb. 190 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics (a) MASH 3-60, Center Impact Point and 25-Degree Impact Angle (b) MASH 3-60, Center Impact Point and 0-Degree Impact Angle Figure 151. Case 54-11ga, 20-ft Tall Pole with Dual 4-ft Long Mast Arm â Pole Contacting Vehicleâs Roof 191 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 34. Updated Simulation Results for Pole Configurations â Maximum Occupant Compartment Deformation (in.), MASH 3-60 Pole Arm and Mass at CG MASH 3-60 Mast Arm Mast Thickness Pole Weight Left 1/4 Center Right 1/4 Sim. No. Height Connection Ends Height Length (ft) Config. (in.) Weight (lb) (lb) (ft) (lb) (lb) (ft) 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 0.9 (C) 1.4 1.3 (W) 0.4 (A) 0.6 (A) 0.4 (A) 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 1.1 (C) 1.0 (C) 2.6 6.7 N/A N/A 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 N/A 0.3 (B) 1.16 1.52 (A) 0.6 (A) 0.3 (A) 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 0.9 (C) N/A 3.38 1.7 (A) 0.6 (A) 0.4 (A) 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 N/A N/A 0.7 (W) N/A N/A N/A 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 N/A N/A 1.85 N/A N/A N/A 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 N/A 1.18 (C) 3.08 N/A N/A N/A 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 N/A N/A 2.76 0.73 (C) N/A N/A 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 N/A N/A 2.3 N/A N/A N/A 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 N/A 0.2 (A) 2.53 1.15 (C) N/A N/A 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 N/A N/A 3.41 1.26 (A) N/A N/A 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 5.54 6.96 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 3.11 0 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 5.64 1.37 27-7ga 30 30 S 0.1880 500.0 212.0 75 787 24.30 NB NB NB NB NB NB 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 N/A 0.57 (C) 3.86 0.90 N/A N/A 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 N/A 2.2 4.45 2.23 N/A N/A 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 N/A 1.94 (C) 3.68 5.03 N/A N/A 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 N/A N/A 3.44 1.86 (C) N/A N/A 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 N/A 1.68 (C) 1.71 4.82 N/A N/A 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 N/A N/A 1.68 1.88 N/A N/A 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 N/A N/A 5.4 3.47 N/A N/A 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 7.11 3.26 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 6.5 6.2 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 3.27 N/A 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 1.96 2.65 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 N/A N/A 3.31 0.9 (C) N/A N/A 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 NB NB 0.94 (W) 5.12 N/A NB 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 N/A NB 8.11 1.5 (C) N/A NB 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 N/A NB 4.2 0.6 (C) N/A NB 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 N/A NB 4.81 2 N/A NB 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 NB NB 0.4 (A) 7.28 N/A NB 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 6.35 1.42 (C) 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 4.66 3.05 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 N/A NB 0.75 (C) 0.87 (C) NB NB 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 NB NB 7.90 9.50 N/A NB 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 9.25 8.80 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 3.98 N/A 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 NB NB 8.30 6.75 NB NB Low potential to pass MASH (deformation > 4.0 in.) Medium potential to pass MASH (0.0 in. < deformation ⤠4.0 in.) âA,â âB,â âC,â and âWâ stand for A-pillar, B-pillar, C-pillar, and windshield deformation. âNBâ denotes âdid not break away,â and âN/Aâ indicates that pole did not contact any part of vehicle. 192 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 35. Updated Simulation Results for Pole Configurations â Maximum Occupant Compartment Deformation (in.), MASH 3-61 and MASH 3-62 Pole Arm and Mass at CG MASH 3-61 MASH 3-62 Mast Arm Mast Thickness Pole Weight Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Sim. No. Height Connection Ends Height Length (ft) Config. (in.) Weight (lb) (lb) (ft) (lb) (lb) (ft) 0 25 0 25 0 25 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 N/A N/A N/A N/A 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 N/A N/A N/A N/A 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 N/A N/A N/A N/A 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 N/A N/A N/A N/A 27-7ga 30 30 S 0.1880 500.0 212.0 75 787 24.30 N/A N/A N/A N/A 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 N/A N/A N/A N/A 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 N/A N/A N/A N/A 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 N/A N/A N/A N/A 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 N/A N/A N/A N/A 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 N/A N/A N/A N/A 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 N/A N/A N/A N/A 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 N/A N/A N/A N/A 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 N/A N/A N/A N/A 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 N/A N/A N/A N/A 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 N/A N/A N/A N/A 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 N/A N/A N/A N/A 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 N/A N/A N/A N/A 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 N/A N/A N/A N/A 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 N/A N/A N/A N/A âN/Aâ indicates that pole did not contact any part of vehicle. 193 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 36. Updated Simulation Results for Pole Configurations â Maximum Occupant Compartment Deformation (in.), MASH 3-60 Ranked Based on Total System Weight Pole Mast Arm Arm and Mass at CG MASH 3-60 Mast Thickness Pole Weight Left 1/4 Center Right 1/4 Sim. No. Height Length Connection Ends Height Config. (in.) Weight (lb) (lb) (ft) (ft) (lb) (lb) (ft) 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 0.9 (C) 1.4 1.3 (W) 0.4 (A) 0.6 (A) 0.4 (A) 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 N/A 0.3 (B) 1.16 1.52 (A) 0.6 (A) 0.3 (A) 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 N/A N/A 0.7 (W) N/A N/A N/A 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 1.1 (C) 1.0 (C) 2.6 6.7 N/A N/A 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 N/A 1.18 (C) 3.08 N/A N/A N/A 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 N/A N/A 2.3 N/A N/A N/A 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 N/A N/A 1.85 N/A N/A N/A 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 0.9 (C) N/A 3.38 1.7 (A) 0.6 (A) 0.4 (A) 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 N/A N/A 3.41 1.26 (A) N/A N/A 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 N/A 0.57 (C) 3.86 0.90 N/A N/A 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 3.11 0 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 N/A 1.94 (C) 3.68 5.03 N/A N/A 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 N/A N/A 2.76 0.73 (C) N/A N/A 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 NB NB 0.94 (W) 5.12 N/A NB 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 5.54 6.96 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 N/A 1.68 (C) 1.71 4.82 N/A N/A 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 N/A 2.2 4.45 2.23 N/A N/A 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 N/A NB 4.2 0.6 (C) N/A NB 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 5.64 1.37 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 N/A 0.2 (A) 2.53 1.15 (C) N/A N/A 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 N/A N/A 3.44 1.86 (C) N/A N/A 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 N/A N/A 5.4 3.47 N/A N/A 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 N/A NB 8.11 1.5 (C) N/A NB 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 6.5 6.2 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 NB NB 0.4 (A) 7.28 N/A NB 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 N/A NB 4.81 2 N/A NB 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 1.96 2.65 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 7.11 3.26 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 4.66 3.05 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 N/A N/A 1.68 1.88 N/A N/A 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 6.35 1.42 (C) 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 3.27 N/A 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 N/A NB 0.75 (C) 0.87 (C) NB NB 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 NB NB 7.90 9.50 N/A NB 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 3.98 N/A 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 N/A N/A 3.31 0.9(C) N/A N/A 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 9.25 8.80 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 NB NB 8.30 6.75 NB NB Low potential to pass MASH (deformation > 4.0 in.) Medium potential to pass MASH (0.0 in. < deformation ⤠4.0 in.) âA,â âB,â âC,â and âWâ stand for A-pillar, B-pillar, C-pillar, and windshield deformation. âNBâ denotes âdid not break away,â and âN/Aâ indicates that pole did not contact any part of vehicle. 194 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics In test nos. 3-61 and 3-62, the vehicle travels at a higher speed and passes underneath the pole before the pole impacts the vehicleâs roof. No occurrences were observed in MASH 3-61 and 3-62 impacts that would suggest a scenario in which the pole would come into contact with a high- speed vehicle. As of the present, no full-scale crash tests have been conducted under the MASH 3-61 and 3-62 impact conditions, and the LS-DYNA simulations involving high-speed scenarios have not been validated through these tests. Thus, there is a clear future need to include MASH 3-61 and MASH 3-62 impact conditions in the testing and validation process. The simulation results showed that in low-speed impacts (i.e., 19 mph), there is a high likelihood of the pole making contact with the small car (1100C vehicle). In high-speed impacts, (i.e., 62 mph), the pole tends to pass over the vehicle without contact. As a follow-up, additional simulations were conducted with impact speeds ranging from 19 to 62 mph to determine the impact speed at which the pole would not contact the car. Similarly, additional simulations were conducted with a 2270P pickup truck with impact speeds below 62 mph. These simulations were conducted to find the maximum speed (below 62 mph) at which pole contact with the truck was initiated, which would raise concerns about potential roof crush issues. Two luminaire poles with 20-ft and 50-ft heights were investigated, as shown in Table 37. In the case of shorter poles, i.e., 20 ft in height, simulations indicated that the average speed at which the pole made contact with either small cars or pickup trucks was around 30 mph. For taller poles, such as 50 ft in height, the simulations suggest that the average speed at which contact with vehicles occurred was approximately 40 mph. Table 37. Additional LS-DYNA Simulations with Intermediate Impact Speeds Low Speed High Speed Intermediate Pole Configuration Vehicle (19 mph) (62 mph) Speed At 19 mph Case no. 54-11ga At 62 mph (MASH At 31 mph, still Small (MASH 3-60), (20 ft tall pole with dual 3-61), pole did not pole impacted Car pole impacted 4-ft long mast arms) impact small car small car small car At 62 mph (MASH Case no. 54-11ga At 29 mph, Pickup 3-62), pole did not (20 ft tall pole with dual N/A pole impacted Truck impact pickup 4-ft long mast arms) pickup truck truck Case no. 101-7ga At 19 mph At 62 mph (MASH At 42 mph, (50 ft tall pole with dual Small (MASH 3-60) pole 3-61), pole did not pole impacted 4-ft long mast arms) Car impacted small car impact small car small car Case no. 101-7ga At 62 mph (MASH At 39 mph, (50 ft tall pole with dual Pickup 3-62), pole did not N/A pole impacted 4-ft long mast arms) Truck impact pickup pickup truck truck 195 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Longitudinal OIV A summary of the simulated longitudinal OIV for MASH 3-60, 3-61, and 3-62 is listed Table 38. The empty cells indicate that simulations for those specific impact conditions were not conducted for the given pole configurations. Also, for a better comparison, the simulated roof crush data was ordered based on the total system weight, as shown in Table 39. Several trends were identified from the analysis of the simulation results in terms of OIV. First, all OIV values increased from the initial simulations (conducted before full-scale crash testing), as the base model was revised with thicker corner walls and added gussets at the top. In all MASH 3-60, 3-61, and 3-62 impacts, there was a noticeable trend of increasing OIV values as the total system weight increased. The MASH 3-62 impacts showed the least concerning OIVs with all values falling below the MASH limit of 16 ft/s. For MASH 3-61 and MASH 3-62 impacts with a vehicle center impact point and 0-degree impact angle, the OIVs versus pole total weight are shown in Figure 152. The general trend was increased OIV by weight. Moreover, all OIV values for MASH 3-62 were lower than the OIV values associated with MASH 3-61 and MASH 3-60 impacts. As a result, if the impacts with pickup trucks (MASH 3-62 impacts) are successfully validated through future full-scale crash testing, it may eliminate the need for conducting MASH 3-62 full-scale crash tests on any pole configuration. Based on simulation results, if a pole passes the OIV criteria in MASH 3-61 impacts, it is highly likely to also meet the OIV requirements for MASH 3-62 impacts. As shown in Figure 152, MASH 3-61 OIV values for a majority of tall and heavy poles exceeded the MASH limit. Thus, it is recommended that for tall-heavy poles, there is a need for full-scale crash testing for OIV evaluation. 196 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Figure 152. Comparison of Simulated OIVs for Pole Configurations versus Their Weight â MASH 3-61 and 3-62 with Center Impact Point and 0-Degree Impact Angle In the case of MASH 3-61 impacts, the center impact point at a 0-degree angle showed OIV values that were either similar to or higher than those observed in other impact conditions, such as the 25-degree angle, left-quarter, and right-quarter impacts. As such, center impacts at 0-degrees can be considered a suitable representative for assessing OIV in various impact scenarios. In several MASH 3-60 impacts cases where the base did not break away (indicated as "NB" in Table 34), the OIV exceeded 21 ft/s. It is important to note that for left- or right-quarter impact points at a 25-degree angle, a distinct interaction pattern was observed. In these cases, the small car began to yaw and rotate around the base, preventing it from breaking away. However, in vehicle centered impacts, the front end effectively wrapped around the base, eventually causing the base to fracture. There is currently no test with a 25-degree impact angle to validate this behavior (i.e., excessive OIV due to the vehicle yawing around the base and thus not breaking away smoothly). Therefore, as of now, no definitive conclusions can be drawn. In previous literature, there were pendulum tests that indicated the 0-degree impact angle to be more critical than the 25-degree angle in terms of breakaway behavior. However, the base design had several modifications, including the addition of gussets at the top and bottom of the base at the corners, as well as an increase in wall thickness 197 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics at the corners. This historical change was undertaken in response to improve wind load stability. As there is no available data on the base behavior impacted at 25 degrees after modifications to evaluate the effect of these changes, it is necessary to conduct full-scale crash tests with a 25-degree impact angle and vehicle left- or right-quarter impacts to investigate this behavior further. This behavior appeared in the new set of simulations with the modified base model. If such behavior is validated through full-scale crash testing, it would become necessary to run one full- scale crash test with this impact condition to assess the OIV criterion. Note that a 0-degree centered impact remains critical for assessing roof crush concerns. The OIV concern associated with a 25-degree impact angle and left- or right-quarter impact point appears to be a consistent pattern across all pole configurations, ranging from 20 ft to 50 ft in height. To conclusively address this concern, conducting a single full-scale crash test under this specific impact condition is needed. Upon completion of this test, the research team will be able to provide further guidelines regarding the necessity of such a crash test for assessing OIV for luminaire poles. Potential to Pass MASH The expected potential to pass the MASH safety criteria (including roof crush and OIV) for each pole configuration is shown in Table 40. All the tests marked as low potential to pass MASH safety criteria (red colored cells) were due to either occupant compartment deformation values or OIVs that exceeded MASH limits. A test marked âMedâ indicates a medium potential to pass the MASH criteria, meaning that at least one measure of the safety criteria exceeded the preferred limit in MASH or resulted in a concerning value if no preferred limit exists (i.e., OIV > 14 ft/s or/and roof crush between 0 and 4 in.). A test marked âHighâ indicates a high potential to pass the MASH criteria, meaning that there were no concerns regarding occupant compartment deformation, OIV, ORA, or vehicle instability. The blank cells have not been simulated. 198 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 38. Updated Simulation Results for Pole Configurations â Longitudinal OIV (ft/s), MASH 3-60, MASH 3-61, and MASH 3-62 Pole Mast Arm Arm Mass at MASH 3-60 MASH 3-61 MASH 3-62 Mast Thickness Pole Weight Sim. No. Height Length Connection Ends CG (ft) Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Config. (in.) Weight (lb) (lb) (ft) (ft) (lb) (lb) 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 10.22 14.31 12.85 14.13 10.22 17.16 10.85 12.12 11.49 11.59 11.01 11.89 5.82 7.79 6.53 9.17 5.73 7.69 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 10.34 12.81 12.88 13.45 11.28 16.18 11.18 12.36 11.60 11.59 11.26 11.55 5.79 5.36 6.58 6.59 5.72 5.64 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 10.03 12.35 12.94 13.97 11.52 16.12 10.98 12.24 10.33 11.51 11.06 11.88 5.53 5.61 6.57 6.58 5.78 5.67 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 10.29 12.08 12.92 13.27 11.33 16.21 11.13 12.31 10.56 11.67 11.23 11.68 5.79 5.75 6.55 6.70 5.80 5.64 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 9.93 15.76 12.74 13.54 10.41 15.46 12.56 12.29 12.05 11.99 11.84 12.35 5.77 5.97 6.67 6.89 5.71 6.01 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 10.50 15.45 12.98 13.65 11.31 15.25 11.84 12.26 12.27 12.05 11.31 12.42 5.80 5.92 6.78 7.11 5.70 6.00 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 9.95 15.57 12.90 14.81 11.13 14.81 11.65 12.21 12.11 11.86 11.93 12.51 5.76 5.99 6.64 6.88 5.72 5.99 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 10.49 13.64 12.81 13.52 10.70 15.11 11.98 12.20 12.33 12.10 12.00 12.52 5.79 5.94 6.77 7.17 5.81 5.99 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 10.54 14.90 12.80 13.76 11.48 14.92 11.70 12.19 12.07 12.09 11.79 12.47 5.77 5.95 6.75 6.93 5.79 5.95 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 10.65 16.06 12.97 14.13 10.63 15.06 12.26 12.26 12.18 12.26 12.02 12.54 5.96 6.01 7.09 7.13 5.87 5.94 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 10.52 16.03 13.33 14.05 12.19 18.39 13.75 13.33 7.49 7.80 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 13.47 14.46 13.65 13.49 7.49 8.24 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 13.35 13.89 13.54 13.35 7.38 7.82 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 13.26 13.59 13.91 13.49 7.51 8.13 27-7ga 30 30 S 0.1880 500.0 212.0 75 787 24.30 31.33 29.98 32.21 26.99 33.17 30.71 17.59 17.50 10.98 10.90 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 9.33 15.40 12.69 12.27 10.46 13.59 12.50 13.64 13.34 13.05 13.07 13.21 6.13 6.53 7.24 7.23 6.45 6.13 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 9.89 17.35 12.61 12.43 10.34 18.49 13.21 12.99 13.58 13.49 12.89 13.60 6.32 6.78 7.55 7.59 6.55 6.45 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 10.40 14.77 12.78 12.43 10.34 13.77 12.76 13.69 13.33 13.28 13.00 13.39 6.27 6.48 7.40 7.33 6.46 6.33 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 10.16 17.09 12.75 12.28 10.68 18.07 13.50 13.99 13.64 13.55 13.15 13.40 6.36 6.79 7.57 7.70 6.67 6.46 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 10.30 15.00 13.06 12.12 10.90 13.96 12.91 13.75 13.45 13.40 12.83 13.39 6.25 6.65 7.42 7.46 6.53 6.52 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 10.18 15.92 12.91 12.57 10.41 18.17 13.39 14.13 13.84 13.72 13.36 13.36 6.55 6.67 7.61 7.72 6.59 6.58 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 11.04 17.36 13.70 12.47 11.11 15.50 15.73 15.72 9.00 8.62 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 13.35 12.38 15.85 15.78 9.07 8.89 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 13.29 12.71 15.61 15.50 8.75 8.70 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 13.88 12.84 16.06 15.90 9.20 8.91 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 13.41 12.53 15.78 16.07 9.04 8.79 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 14.08 17.63 14.04 12.85 11.07 19.93 16.20 15.78 9.29 8.94 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 23.62 26.60 17.02 17.60 17.04 26.60 13.53 14.57 14.51 13.76 14.31 14.11 6.90 7.24 8.30 8.22 7.17 8.24 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 14.65 29.63 15.64 15.31 18.07 21.40 14.04 14.70 14.57 13.82 14.24 14.45 7.18 7.52 8.42 8.43 7.33 7.74 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 14.48 29.73 15.56 15.37 19.98 20.58 13.59 14.59 14.48 13.64 13.99 14.37 7.17 7.69 8.34 8.54 7.36 8.09 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 18.00 29.38 15.79 18.93 20.17 20.94 14.02 14.69 14.40 13.93 13.97 14.48 7.25 7.70 8.45 8.52 7.48 8.04 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 25.16 29.12 16.28 15.37 20.82 27.14 15.80 15.50 9.75 9.61 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 16.08 17.02 15.87 15.10 10.03 9.84 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 15.94 15.55 15.77 15.53 9.88 9.69 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 17.50 30.40 16.72 16.11 23.60 23.83 16.08 15.32 10.30 10.10 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 24.28 29.72 16.82 16.01 20.27 29.64 17.47 16.93 11.21 10.99 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 16.61 15.77 17.43 16.96 11.42 11.34 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 16.46 15.35 16.68 17.03 11.36 11.22 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 23.00 30.18 16.55 16.20 26.70 29.74 17.47 16.93 11.55 11.58 Low potential to pass MASH (OIV > 16 ft/s) Medium potential to pass MASH (14 ft/s < deformation ⤠16 ft/s) 199 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 39. Updated Longitudinal OIV (ft/s), MASH 3-60, MASH 3-61, and MASH 3-62 Ranked Based on Total System Weight Pole Mast Arm Arm Mass at MASH 3-60 MASH 3-61 MASH 3-62 Mast Thickness Pole Weight Sim. No. Height Length Connection Ends CG (ft) Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Config. (in.) Weight (lb) (lb) (ft) (ft) (lb) (lb) 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 143.2 40.6 75 259 12.01 10.22 14.31 12.85 14.13 10.22 17.16 10.85 12.12 11.49 11.59 11.01 11.89 5.82 7.79 6.53 9.17 5.73 7.69 6-11ga 20 15 S 0.1196 143.2 86.8 75 305 13.79 10.03 12.35 12.94 13.97 11.52 16.12 10.98 12.24 10.33 11.51 11.06 11.88 5.53 5.61 6.57 6.58 5.78 5.67 19-11ga 30 4 S 0.1196 225.4 40.6 75 341 16.66 9.93 15.76 12.74 13.54 10.41 15.46 12.56 12.29 12.05 11.99 11.84 12.35 5.77 5.97 6.67 6.89 5.71 6.01 54-11ga 20 4 D 0.1196 143.2 81.2 150 374 14.60 10.34 12.81 12.88 13.45 11.28 16.18 11.18 12.36 11.60 11.59 11.26 11.55 5.79 5.36 6.58 6.59 5.72 5.64 24-11ga 30 15 S 0.1196 225.4 86.8 75 387 18.67 9.95 15.57 12.90 14.81 11.13 14.81 11.65 12.21 12.11 11.86 11.93 12.51 5.76 5.99 6.64 6.88 5.72 5.99 78-11ga 30 20 S 0.1196 225.4 152.0 75 452 20.60 10.54 14.90 12.80 13.76 11.48 14.92 11.70 12.19 12.07 12.09 11.79 12.47 5.77 5.95 6.75 6.93 5.79 5.95 72-11ga 30 4 D 0.1196 225.4 81.2 150 457 20.00 10.50 15.45 12.98 13.65 11.31 15.25 11.84 12.26 12.27 12.05 11.31 12.42 5.80 5.92 6.78 7.11 5.70 6.00 59-11ga 20 15 D 0.1196 143.2 173.6 150 467 16.73 10.29 12.08 12.92 13.27 11.33 16.21 11.13 12.31 10.56 11.67 11.23 11.68 5.79 5.75 6.55 6.70 5.80 5.64 19-7ga 30 4 S 0.1880 354.3 40.6 75 470 16.20 10.52 16.03 13.33 14.05 12.19 18.39 13.75 13.33 7.49 7.80 35-11ga 40 4 S 0.1196 367.4 40.6 75 483 21.23 9.33 15.40 12.69 12.27 10.46 13.59 12.50 13.64 13.34 13.05 13.07 13.21 6.13 6.53 7.24 7.23 6.45 6.13 24-7ga 30 15 S 0.1880 354.3 86.8 75 516 17.82 13.35 13.89 13.54 13.35 7.38 7.82 40-11ga 40 15 S 0.1196 367.4 86.8 75 529 23.21 10.40 14.77 12.78 12.43 10.34 13.77 12.76 13.69 13.33 13.28 13.00 13.39 6.27 6.48 7.40 7.33 6.46 6.33 77-11ga 30 15 D 0.1196 225.4 173.6 150 549 22.30 10.49 13.64 12.81 13.52 10.70 15.11 11.98 12.20 12.33 12.10 12.00 12.52 5.79 5.94 6.77 7.17 5.81 5.99 48-10ga 50 4 S 0.1345 467.0 40.6 75 583 24.81 23.62 26.60 17.02 17.60 17.04 26.60 13.53 14.57 14.51 13.76 14.31 14.11 6.90 7.24 8.30 8.22 7.17 8.24 72-7ga 30 4 D 0.1880 354.3 81.2 150 586 18.98 13.47 14.46 13.65 13.49 7.49 8.24 41-11ga 40 20 S 0.1196 367.4 151.5 75 594 25.29 10.30 15.00 13.06 12.12 10.90 13.96 12.91 13.75 13.45 13.40 12.83 13.39 6.25 6.65 7.42 7.46 6.53 6.52 88-11ga 40 4 D 0.1196 367.4 81.2 150 599 24.85 9.89 17.35 12.61 12.43 10.34 18.49 13.21 12.99 13.58 13.49 12.89 13.60 6.32 6.78 7.55 7.59 6.55 6.45 53-10ga 50 15 S 0.1345 467.0 86.8 75 629 26.94 14.48 29.73 15.56 15.37 19.98 20.58 13.59 14.59 14.48 13.64 13.99 14.37 7.17 7.69 8.34 8.54 7.36 8.09 77-7ga 30 15 D 0.1880 354.3 173.6 150 678 21.21 13.26 13.59 13.91 13.49 7.51 8.13 79-11ga 30 20 D 0.1196 225.4 303.0 150 678 24.60 10.65 16.06 12.97 14.13 10.63 15.06 12.26 12.26 12.18 12.26 12.02 12.54 5.96 6.01 7.09 7.13 5.87 5.94 93-11ga 40 15 D 0.1196 367.4 173.6 150 691 27.56 10.16 17.09 12.75 12.28 10.68 18.07 13.50 13.99 13.64 13.55 13.15 13.40 6.36 6.79 7.57 7.70 6.67 6.46 35-7ga 40 4 S 0.1880 578.0 40.6 75 694 20.59 11.04 17.36 13.70 12.47 11.11 15.50 15.73 15.72 9.00 8.62 101-10ga 50 4 D 0.1345 467.0 81.2 150 698 28.92 14.65 29.63 15.64 15.31 18.07 21.40 14.04 14.70 14.57 13.82 14.24 14.45 7.18 7.52 8.42 8.43 7.33 7.74 40-7ga 40 15 S 0.1880 578.0 86.8 75 740 22.10 13.29 12.71 15.61 15.50 8.75 8.70 48-7ga 50 4 S 0.1880 652.1 40.6 75 768 24.19 25.16 29.12 16.28 15.37 20.82 27.14 15.80 15.50 9.75 9.61 27-7ga 30 30 S 0.1880 500.0 212.0 75 787 24.30 31.33 29.98 32.21 26.99 33.17 30.71 17.59 17.50 10.98 10.90 106-10ga 50 15 D 0.1345 467.0 173.6 150 791 31.96 18.00 29.38 15.79 18.93 20.17 20.94 14.02 14.69 14.40 13.93 13.97 14.48 7.25 7.70 8.45 8.52 7.48 8.04 41-7ga 40 20 S 0.1880 578.0 151.5 75 804 23.78 13.41 12.53 15.78 16.07 9.04 8.79 88-7ga 40 4 D 0.1880 578.0 81.2 150 809 23.43 13.35 12.38 15.85 15.78 9.07 8.89 53-7ga 50 15 S 0.1880 652.1 86.8 75 814 25.91 15.94 15.55 15.77 15.53 9.88 9.69 94-11ga 40 20 D 0.1196 367.4 303.0 150 820 30.04 10.18 15.92 12.91 12.57 10.41 18.17 13.39 14.13 13.84 13.72 13.36 13.36 6.55 6.67 7.61 7.72 6.59 6.58 101-7ga 50 4 D 0.1880 652.1 81.2 150 883 27.57 16.08 17.02 15.87 15.10 10.03 9.84 93-7ga 40 15 D 0.1880 578.0 173.6 150 902 25.69 13.88 12.84 16.06 15.90 9.20 8.91 106-7ga 50 15 D 0.1880 652.1 173.6 150 976 30.19 17.50 30.40 16.72 16.11 23.60 23.83 16.08 15.32 10.30 10.10 48-3ga 50 4 S 0.2500 867.3 40.6 75 983 23.75 24.28 29.72 16.82 16.01 20.27 29.64 17.47 16.93 11.21 10.99 53-3ga 50 15 S 0.2500 867.3 86.8 75 1029 25.15 16.46 15.35 16.68 17.03 11.36 11.22 94-7ga 40 20 D 0.1880 578.0 303.0 150 1031 27.94 14.08 17.63 14.04 12.85 11.07 19.93 16.20 15.78 9.29 8.94 101-3ga 50 4 D 0.2500 867.3 81.2 150 1099 26.54 16.61 15.77 17.43 16.96 11.42 11.34 106-3ga 50 15 D 0.2500 867.3 173.6 150 1191 28.80 23.00 30.18 16.55 16.20 26.70 29.74 17.47 16.93 11.55 11.58 Low potential to pass MASH (OIV > 16 ft/s) Medium potential to pass MASH (14 ft/s < deformation ⤠16 ft/s) 200 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 40. Simulated Potential of Passing MASH for All Pole Configurations Pole Mast Arm MASH 3-60 MASH 3-61 MASH 3-62 Mast Thickness Weight Sim. No. Height Length CG (ft) Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Left 1/4 Center Right 1/4 Config. (in.) (lb) (ft) (ft) 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 25 1-11ga 20 4 S 0.1196 259 12.01 Med Med Med Med Med Low High High High High High High High High High High High High 54-11ga 20 4 D 0.1196 374 14.60 Med Med Med Low High Low High High High High High High High High High High High High 6-11ga 20 15 S 0.1196 305 13.79 High Med Med Med Med Low High High High High High High High High High High High High 59-11ga 20 15 D 0.1196 467 16.73 Med High Med Med Med Low High High High High High High High High High High High High 19-11ga 30 4 S 0.1196 341 16.66 High High Med High High High High High High High High High High High High High High High 72-11ga 30 4 D 0.1196 457 20.00 High High Med High High High High High High High High High High High High High High High 24-11ga 30 15 S 0.1196 387 18.67 High Med Med High High High High High High High High High High High High High High High 77-11ga 30 15 D 0.1196 549 22.30 High High Med Med High High High High High High High High High High High High High High 78-11ga 30 20 S 0.1196 452 20.60 High High Med High High High High High High High High High High High High High High High 79-11ga 30 20 D 0.1196 678 24.60 High Low Med Med High High High High High High High High High High High High High High 19-7ga 30 4 S 0.1880 470 16.20 High Low Med Med High Low High High High High 72-7ga 30 4 D 0.1880 586 18.98 Low Low High High High High 24-7ga 30 15 S 0.1880 516 17.82 Med High High High High High 77-7ga 30 15 D 0.1880 678 21.21 Low Med High High High High 27-7ga 30 30 S 0.1880 787 24.30 Low Low Low Low Low Low Low Low High High 35-11ga 40 4 S 0.1196 483 21.23 Med Med Med High High High High High High High High High High High High High High 88-11ga 40 4 D 0.1196 599 24.85 High Low Low Med High Low High High High High High High High High High High High High 40-11ga 40 15 S 0.1196 529 23.21 High Med Med Low High High High High High High High High High High High High High High 93-11ga 40 15 D 0.1196 691 27.56 High Low Med Med High Low High Med High High High High High High High High High High 41-11ga 40 20 S 0.1196 594 25.29 High Med Med Low High High High High High High High High High High High High High High 94-11ga 40 20 D 0.1196 820 30.04 High High Med Med High Low High Med High High High High High High High High High High 35-7ga 40 4 S 0.1880 694 20.59 High Low Low Med High Low Med Med High High 88-7ga 40 4 D 0.1880 809 23.43 Low Med Med Med High High 40-7ga 40 15 S 0.1880 740 22.10 Low Low Med Med High High 93-7ga 40 15 D 0.1880 902 25.69 Med High Med Med High High 41-7ga 40 20 S 0.1880 804 23.78 Med Med Med Low High High 94-7ga 40 20 D 0.1880 1031 27.94 Med Low Med Med High Low Low Med High High 48-10ga 50 4 S 0.1345 583 24.81 Low Low Low Low Low Low Med Med Med Med Med Med High High High High High High 101-10ga 50 4 D 0.1345 698 28.92 Med Low Low Med Low Low Med Med Med Med Med Med High High High High High High 53-10ga 50 15 S 0.1345 629 26.94 Med Low Low Med Low Low Med Med Med Med Med Med High High High High High High 106-10ga 50 15 D 0.1345 791 31.96 Low Low Low Med Low Low Med Med Med Med Med Med High High High High High High 48-7ga 50 4 S 0.1880 768 24.19 Low Low Low Med Low Low Med Med High High 101-7ga 50 4 D 0.1880 883 27.57 Low Low Med Med High High 53-7ga 50 15 S 0.1880 814 25.91 Low Med Med Med High High 106-7ga 50 15 D 0.1880 976 30.19 Low Low Low Low Low Low Low Med High High 48-3ga 50 4 S 0.2500 983 23.75 Low Low Low Low Low Low Low Low High High 101-3ga 50 4 D 0.2500 1099 26.54 Low Med Low Low High High 53-3ga 50 15 S 0.2500 1029 25.15 Low Med Low Low High High 106-3ga 50 15 D 0.2500 1191 28.80 Low Low Low Low Low Low Low Low High High Low potential to pass MASH Medium potential to pass MASH 201 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics 6.2 Analysis of Breakaway Sign Supports â PSST Posts 6.2.1. Full-Scale Crash Testing â PSST Posts Five full-scale crash tests were conducted on PSST sign support systems to validate the simulation results. Chapter 4 provides a summary from these tests. While the test outcomes did not match perfectly with the simulation results for all five crash tests, the overall conclusions drawn from the computer simulations were still deemed valid. The main factor contributing to the differences between the tests and simulations was identified as the soil strength. The initial simulations had assumed a stronger soil strength, leading to premature post shearing and differing responses of the sign system in some tests. However, through the process of updating the soil properties in the models more consistent results were achieved, as evidenced in Chapter 5. 6.2.2. Updated Computer Simulation â PSST Posts The calibrated models were employed to rerun the matrix of simulations to check and update the conclusions from the initial simulation results. Similar to the original analyses, the matrix of simulations included a range of sign support and impact configurations. The panel sizes were diversified from 1 ft x 1½ ft to 4 ft x 5 ft (Figure 153). Sign panels with gauge thicknesses from 0.08 to 0.12 in. were utilized with some models. In all models, aluminum material was assigned to the sign panels. (a) 1âx1.5â (b) 2âx2â (c) 2.5âx2.5â (d) 3âx3â (e) 3âx4â (f) 4âx5â Figure 153. Panel Sizes Incorporated in Matrix of Simulations The post size chosen was a 2¼-in. x 2¼-in. cross-section with a 12-gauge thickness for all simulations. Maintaining the most common configuration, all models utilized a 7-ft mounting 202 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics height to the bottom of the sign panel. The anchor size of 2½ in. x 2½ in. with 12-gauge thickness was selected to accommodate the post size. ASTM A1011 Grade 50 steel was used for both the post and anchor in all simulations. The anchor embedment depth was standardized at 36 in. into the ground for all models. Importantly, the updated soil properties were applied in these models. The simulations encompassed three MASH impact configurations (test nos. 3-60, 3-61, and 3-62) (Figure 154). Furthermore, different impact locations (center, left-side offset, and right-side offset) and impact angles (0, and 25 degrees) were incorporated into the simulations (Figure 155). To provide a concise overview of the parameters. Table 41 highlights the various factors explored in this matrix of simulations. (a) 3-60 (b) 3-61 (c) 3-62 Figure 154. Impact Conditions Considered in the Matrix of Simulations (a) Center (b) Left-side offset (c) Right-side offset (a) 0-deg (b) +25-deg (c) -25 deg Figure 155. Varied Impact Locations and Impact Angle 203 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 41. Example of Family of Devices â PSST Sign Support Device Family 2¼-in. 12-gauge Single PSST Sign Support Identical, Critical Structural Feature Sign support section and size 2¼-in., 12-gauge PSST 1 ft x 1½ ft, 2 ft x 2 ft, Sign panel size 2½ ft x 2½ ft, 3 ft x 3 ft (if applicable, a lower smaller 3 ft x 4 ft, 4 ft x 5 ft advisory panel may potentially (recommended from be considered) NCHRP 03-119) Potential parameters that provide 7 ft (recommended from Sign panel mounting height similar safety performance under NCHRP 03-119) MASH impact conditions Aluminum (recommended Sign panel material from NCHRP 03-119) Sign panel thickness 0.08 in., 0.10 in., 0.120 in. Support embedment/foundation 36 in. With and without wind Presence of wind beams beams Table 42 shows sample results from one of the PSST sign support simulations. A similar summary figure was generated for each of the simulations carried out under this project and is included in Error! Reference source not found.The figure shows the predicted behavior of the PSST sign support, the vehicle, and all the pertinent MASH metrics and evaluations. The basic sign features and impact conditions are indicated in the upper part of the table. In the case shown in Table 42, the sign was made up of a 2¼-in. x 2¼-in. square tube with 12-gauge thickness. The post was anchored using a 2½-in. x 2½-in. square tube with 12-gauge thickness. Both the post and anchor tubes were made from A1011 Grade 50 steel. The sign blank was 1-ft x 1.5-ft in size, 0.08 in. thick, and was made of aluminum. The vehicle model used in this simulation was based on the 1100C MASH test vehicle. The impact condition was that of MASH test no. 3-60. The impact angle was 0 degrees, and the sign system was offset by ¼ the vehicle width toward the driverâs side. The pictures in the table show âsnapshotsâ of the vehicle and sign positions at three points in time from two different views (side and isometric). The visual snapshots provide a convenient means to assess the performance of the sign support. The lower part of the table provides a summary of the MASH crashworthiness evaluation metrics for the condition that was simulated. These summary figures were used to assess the different parametersâ effects on the sign systemâs MASH performance and develop guidelines for testing a family of these devices. A considerable amount of information was generated by the simulations. Table 43 shows a summary of all cases incorporating the results from the updated models. The critical metrics for the PSST system are the Occupant Impact Velocity (OIV), windshield intrusion, and roof deformation. These metrics are included in the table and used to assess whether the cases would meet MASH criteria. Green shaded cells in the table indicate that the case met all MASH criteria while red shaded cells indicate that one or more metrics did not meet MASH. As before, most of the cases that did not meet MASH criteria were attributed to excess windshield penetrations (which must be less than 3 in. and no tearing). A few cases, mostly with the largest panel, did not meet the roof deformation criteria (which must be less than 4 in.). 204 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 42. Sample Summary of Simulation Results Single PSST Post Sign Support System Mounting-Height: 7 ft; A1011 Gr.50 Post; Aluminum Panel; Anchor Embedment depth: 36 in Post Size Anchor Size Panel Size MASH Impact Impact Location Impact Angle Wind Beam 2¼â x 2¼â 2½â x 2½â 1â x 1.5â 3-60 Center 0 deg No 12 gauge 12 gauge 0.08â thick Evaluation Criteria The test article should readily activate in a predictable manner by breaking away, fracturing, or B yielding. Pass Detached elements, fragments, or other debris from the test article should not penetrate or show potential for penetrating the occupant compartment, or present undue hazard to other traffic, Pass pedestrians, or personnel in a work zone. D All Deformations of, or intrusions into, the occupant compartment should not exceed limits set forth in Section 5.3 Roof ⤠4 in. 0 and Appendix E of MASH. [Roof less than 4.0 in (101.6 mm). Pass Windshield-no tear of plastic liner and maximum deformation Windshield ⤠3 0 of 3 in (76.2 mm)] in. The vehicle should remain upright during and after the Max Roll (Deg) 0 F collision. The maximum pitch & roll angles are not to exceed Pass 75 degrees. Max Pitch (Deg) 1 Longitudinal & lateral occupant impact velocities (OIV) Vx (m/s) 5.3 H should fall below the preferred value of 10 ft/s (3.0 m/s), or at Pass least below the maximum allowed value of 16 ft/s (4.9 m/s) Vy (m/s) 0.0 Longitudinal & lateral occupant ridedown accelerations Ax (g) 0.2 I (ORA) should fall below the preferred value of 15.0 g, or at Pass least below the maximum allowed value of 20.49 g Ay (g) 0.2 N Vehicle trajectory behind the test article is acceptable Pass 205 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics Table 43. Summary of Simulation Results Impact Panel Size 1' x 1.5' 2' x 2' 2.5' x 2.5â 3' x 3' 3' x 4' 4' x 5' Impact locations Condition Panel Thickness 0.08 0.10 0.12 0.08 0.10 0.12 0.08 0.10 0.12 0.08 0.10 0.12 0.08 0.10 0.12 0.08 0.10 0.12 and Angle OIV (ft/s) 5.2 5.6 5.6 6.6 7.2 7.2 7.9 8.2 8.2 Center/ Windshield Int. (in) 0 0 0 0 0 0 0 0 0 0-Deg Roof Int. (in) 0 0 0 0 0 0 0 0 0 Driver-Side OIV (ft/s) 5.9 5.9 6.2 7.2 7.5 7.9 7.9 8.5 8.5 8.9 9.2 9.5 9.5 9.8 10.5 11.2 11.5 11.8 MASH Offset/ Windshield Int. (in) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3-60 0-Deg Roof Int. (in) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pass. -Side OIV (ft/s) 5.9 5.9 5.9 7.2 7.5 7.9 8.2 8.5 8.9 Offset/ Windshield Int. (in) 0 0 0 0 0 0 0 0 0 0-Deg Roof Int. (in) 0 0 0 0 0 0 0 0 0 OIV (ft/s) 3.3 6.2 6.6 6.2 6.2 6.9 6.2 5.9 6.2 6.2 5.9 3.9 Center/ Windshield Int. (in) 0 0 0 0 0 0 1.2T 4.7T 8.8T 8.2T 4.3T 0 0-Deg Roof Int. (in) 0 0 0 0 0 0 0 2.8 4.3 4.3 3.9 5.9 OIV (ft/s) 5.9 5.6 6.2 6.6 6.2 6.2 6.2 3.0 6.6 6.2 7.2 4.9 Center/ - Windshield Int. (in) 0 0 0 0 0 0.7T 4.3T 1.2T 3.1T 3.1T 6.7T 3.3T 25-Deg Roof Int. (in) 0 0 0 0 0 0 2.362 0 1.6 1.6 3.9 8.0 OIV (ft/s) 4.9 5.9 5.2 5.6 5.6 7.2 7.2 7.9 7.2 7.2 3.3 6.2 MASH Center/ Windshield Int. (in) 0 0 0 0 0 0.4T 1.6T 2.0T 3.1T 1.8T 6.3T 7.9T 3-61 +25-Deg Roof Int. (in) 0 0 0 0 0 0 2.4 0 0 0 3.6 5.1 Driver-Side OIV (ft/s) 3.3 3.6 3.3 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 1.0 Offset/ Windshield Int. (in) 1.2T 1.6T 4.2T 12.4T 6.8T 12.5T 13.0T 11.8T 4.7T 4.7T 4.1T 0.1 0-Deg Roof Int. (in) 0 0 0.2 3.9 0.2 4.3 3.9 3.9 3.5 3.9 3.3 2.4 Pass. -Side OIV (ft/s) Offset/ Windshield Int. (in) 0-Deg Roof Int. (in) OIV (ft/s) 2.0 2.0 2.3 2.3 2.6 2.3 1.3 2.3 2.3 2.3 2.3 2.3 Center/ Windshield Int. (in) 0 0 0 0 0 0 0 3.9 5.5 0 5.5 3.3 0 3.6 0-Deg Roof Int. (in) 0 0 0 0 0 0 0 4.7 2.4 0 3.0 3.2 0 3.504 OIV (ft/s) 1.6 2.0 2.0 3.0 3.9 3.0 1.6 3.0 1.6 3.3 3.0 3.0 MASH Center/ Windshield Int. (in) 0 0 0 0 0 0 0 3.9 2.8 0 2.4 1.8 0 2.205 3-62 +25-Deg Roof Int. (in) 0 0 0 0 0 0 0 0 0.8 0 1.6 2.8 0 3.0 OIV (ft/s) Center/ - Windshield Int. (in) 25-Deg Roof Int. (in) Meets MASH Criteria Does Not Meet MASH Criteria T Symbol after intrusion number indicates âtearingâ is predicted. 206 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics The upper section of the table displays results from scenarios involving low-speed impacts with a small car (MASH test no. 3-60). The outcomes closely resembled those of the original models, and all cases subjected to this impact assessment met all MASH criteria. In these instances, the sign system bent at ground level but remained connected to the anchoring sleeve. It continued to deform, passing beneath the vehicle without contacting the vehicleâs windshield or roof. The sole critical factor identified in these cases was the OIV. Notably, as the panel size increased, the OIV also increased. However, even with the largest panel size, the OIV remained below the critical MASH threshold. The middle section of Table 43 presents cases involving the high-speed impact with a small car, specifically MASH test no. 3-61. Simulations indicated that this impact was the most severe among the three scenarios. In most of these instances, the post sheared off and became detached from the anchor. Consequently, the post and sign blank pivoted toward the vehicle and made contact with the hood, windshield, and/or the roof, contingent on the size of the sign panel. Several of the MASH test no. 3-61 impact cases failed to meet MASH criteria. The cases that met MASH criteria featured small sign panels. In these scenarios, the post encircled the vehicle and sheared off at the base later in the impact, causing the panel to strike the hood rather than the windshield. However, it is worth noting that even for these cases with small panels, simulations involving offset impacts did not meet MASH criteria. In offset impacts the post ruptured or separated from the base early in the impact, leading to the sign panel impacting the windshield and failing to meet MASH criteria. The early rupture of the post can be attributed to the fact that the vehicle's rigidity is higher in the corner offset point region compared to the center region. Consequently, higher forces are exerted on the post during offset impacts, leading to earlier detachment from the base. In a few simulations featuring the largest panel sizes, the post also sheared at the base, but due to the increased panel height the panel primarily impacted the roof, resulting in less deformation of the windshield. The lower section of Table 43 illustrates the high-speed impact with the pickup truck (MASH test no. 3-62). The simulations revealed that most of the cases involving smaller sign panels (ranging from 1 ft x 1.5 ft to 2.5 ft x 2.5 ft) conformed to MASH criteria, whereas cases featuring larger sign panels (ranging from 3 ft x 3 ft to 4 ft x 5 ft) did not. The primary reason for failing to meet MASH criteria was excessive intrusion and deformation of the windshield. In scenarios with smaller sign panels, the sign made contact with the hood and did not extend to the windshield. However, as the sign systems increased in height, the panel reached the windshield and the roof, resulting in several cases not meeting the MASH criteria. Similar to the original conclusions, if all impact configurations are considered (i.e., all three impacts with different angles and locations have to meet all MASH criteria), all PSST sign support configurations would not meet MASH. 6.2.3. Critical Characteristics The following trends were identified after reviewing the simulation results: ⢠MASH test no. 3-60 was the least critical of the three impacts for the family of the PSST sign support system considered. This test could be omitted or reduced to only one test with the largest sign panel. 207 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
PRE-PUBLICATION DRAFTâUnedited Text and Graphics ⢠MASH test no. 3-61 is the most critical of the three tests for this PSST family of devices. It was noted that the size of the panel affects the MASH performance outcome. Medium sized panels could be more critical than smaller and larger sizes. Tests with the smallest and largest sign would need to be performed and based on the outcome of these tests, additional test may need to be performed (e.g., if the smallest panel hit the hood and the larger panel hit the roof, a test with a size in between would be needed). ⢠Similar effects were noted for MASH test no. 3-62. The panel size affects the MASH performance, and the middle panel size could be more critical than the smallest and largest sizes. Testing can start with the smallest and largest sizes and based on the outcome, additional testing with in-between sizes may be needed. ⢠It was noted that impact locations and impact angle can have an important effect on the outcome of the test. In some cases, offset impacts and impacts at an angle were more critical than the no-offset impact. In other cases, no-offset impact was more critical. Tests with and without offset are needed. 6.2.4. Conclusions A matrix of simulations was rerun with the updated models to verify and update the conclusions from the analyses and understand the effects of different parameters on the MASH performance of a family of PSST post sign support systems. The parameters included: panel size and thickness, impact angle, impact locations, and wind beam. The simulations showed that the evaluated design did not meet the MASH criteria in almost all configurations. The results were used to identify critical tests to validate the simulation results. Coupled with the full-scale crash testing, preliminary guidelines were developed for testing a family of PSST post systems. The guidelines are summarized in Chapter 7. 208 PRE-PUBLICATION DRAFTâUnedited Text and Graphics
