# Crasworthiness Analysis to Evaluate the Performance of TDM-Shielded Street Poles Using FEA
## 4 Results
### Variation of Vehicle Velocity on the Impact Energy Absorption on Street Pole and Vehicle  
From previous results, it can be said that an analysis of the effect of TDM thickness on the vehicle and the street pole is established; it can be considered using a common thickness of 35 mm for the TDM-based shielded street pole to vary the velocity of the vehicle and understand its impact on the mitigation of the impact energy on both the vehicle and the street pole. When initially assessing Figure 10, it can be observed for all velocities, TDM-based reinforcements ensure mitigations on the impact energy that the street pole will receive due to a collision. Figure 8: FEA results of energy absorptions of the street pole after being collided by a vehicle (corner collision scenario) using five different thicknesses of TDM shielding. Figure 9: FEA results of energy absorptions of the vehicle after colliding on a street pole (corner collision scenario) using five different thicknesses of TDM shielding. However, the magnitude of these mitigations decreases with increased velocities. For instance, the street pole's impact energy is mitigated by 22.5% at speeds of about 12 ms\({}^{-1}\). However, when the velocities are increased to about 17 ms\({}^{-1}\) and 22 ms\({}^{-1}\), the influence of the mitigation diminishes with a decrease in energy to about 5.2% and 1.15%, respectively. Therefore, at the highest velocity, since the mitigations are low, TDM reinforcement risks of still cause no difference to the damage suffered on the street pole. With that being  
Figure 10: Impact energies were absorbed by the street pole (one as a bare street pole and the other shielded by TDM material of 35 mm) when collided by the vehicle through a frontal collision scenario at speeds of 12 ms\({}^{-1}\), 17 ms\({}^{-1}\) and 22 ms\({}^{-1}\). stated, it is evident that the TDM-shielded street poles are essential in reducing the overall energy absorption of the street pole during a collision. On the further assessment of the impact energy absorption of street poles during corner-based collision scenarios, as seen in Figure 11, the mitigations shown complement the previous statement, with results showing a reduction of impact energies between 22 and 28% for velocities at 12 ms\({}^{-1}\), 17 ms\({}^{-1}\) and 22 ms\({}^{-1}\). Contrastingly though, the energies reduced are much higher compared to the frontal collision. Since the corner collision scenarios are more likely to occur in a practical scenario, the benefits of having the TDM reinforcement emphasize its necessity to protect the street pole from further damage. Figure 11: Impact energies were absorbed by the street pole (one as a bare street pole and the other shielded by TDM material of 35 mm) when collided by the vehicle through a corner collision scenario at speeds of 12 ms\({}^{-1}\), 17 ms\({}^{-1}\) and 22 ms\({}^{-1}\). While it was expected that the nature of the results of the frontal collision would be similar when comparing the energies absorbed by the street pole to the energies absorbed by the vehicle at respective speeds, this did not happen. As shown in Figure 12, at low speeds, TDM-shielded street poles exert more energy onto the vehicle, although this increase in energy is not too sufficient to create significant damage to the vehicles. For example, at speeds of 12 ms\({}^{-1}\), the energy exerted is 7.2% higher on the vehicle by the TDM-shielded street pole. When comparing this result to the results of the energies absorbed by the street pole, the total energies, in this case, have been mitigated by a large margin. However, when the velocities are increased, as shown in Figure 12, the results then show that TDM-based shielded street poles mitigate the energies absorbed by the vehicle. For instance, the energies of the vehicle are reduced by 7% and 14% at speeds of 17 ms\({}^{-1}\) and 22 ms\({}^{-1}\), respectively, which greatly increases the chances of passengers in the vehicles avoiding serious injuries.