## 4 Results  
### Impact Analysis at Speed of 12 m-s\({}^{-1}\) (43 km/h)  
The results of the impact simulations using velocities of 12 m\(\cdot\)s\({}^{-1}\) show that the plasticity criteria on the vehicle's shell were reached for both frontal and corner collisions. Moreover, the critical elastic-plasticity limit was exceeded for both materials of the street pole--steel and aluminum. It is noteworthy to also mention that for the scenario of the frontal crash on the aluminum street pole, the pole experiences excessive propagation of damage with respect to the damage parameters explained in Section 3.2. This excessive damage results in the structure being completely fractured from its base. Figure 9 represents the graphical representation of the stress distribution on both the street pole and the vehicle after impact. Figure 9: Mises stress distribution of front and corner impact at 12 m\(\cdot\)s\({}^{-1}\). (**a**) Front impact on steel pole, (**b**) corner impact on steel street pole, (**c**) front impact on aluminum street pole, and (**d**) corner impact on aluminum street pole. Furthermore, Figure 10 represents the contours of the deformations on the street pole when impacted by the vehicle. To further understand the nature of these deformations, it was necessary to extract and analyze the specific energy absorptions of the two materials. During this analysis, the results showed that the aluminum street pole absorbs more energy from the crash than the steel pole. This can be seen in Figure 11 where the aluminum street pole's SEA is much greater than that made of steel. Therefore, given a larger thickness, the aluminum street pole may have the potential to further reduce the risk of injury. The SEA in the case of this street pole was calculated using the total internal energy of the street pole and dividing this value by the total mass of the street pole (750.76 kg for the steel street pole and 256.5 kg for the aluminum street pole). However, due to the simulation in Figure 10, showing the aluminum street pole fracturing off its foundation, this means that transportation authorities may have to bear extra costs of fully replacing lighting street poles in the case of such accidents. If most car accidents might occur at such speeds, it is therefore recommended that authorities inform their suppliers of using street poles with thicknesses of more than 10 mm to ensure that aluminum-based street poles do not suffer such consequential damages. Finally, the crashworthiness analysis at 12 m\(\cdot\)s\({}^{-1}\) is an ideal stage to conduct the first validation of this paper in comparison to other literature sources. This is because at higher speeds, the square of the velocity is directly proportional to the kinetic energy; therefore, the differences might be too large to cause uncertainties in the validation. The absorbed energy found in crashworthiness analyses on steel street poles by [PERSON] et al. [14] is compared to those in this paper. Since the validation source was performed on steel samples, the comparison can only be valid for results covered for street poles composed of the ASTM A36 steel street pole. As shown in Figure 12, the results of both crashworthiness analyses  
Figure 10: Contours on the deformation of the steel or aluminum street poles at 12 m\(\cdot\)s\({}^{-1}\). (**a**) Center impact on steel street pole, (**b**) corner impact on steel street pole, (**c**) center impact on aluminum street pole, and (**d**) corner impact on aluminum street pole. have similar values. The main difference between the data is that the diameter of the street pole in the literature source published by [PERSON] et al. [14] is about 1.5 m, while in the current simulations, we used street poles of about 2.5 m diameter. Therefore, the influence of the larger diameter will obviously lead to higher energy extracted in these simulations.