**3. Results and Discussion**

*3.1. Comparison of Impulse between Experiment and Simulation*

Figure 9 compares the experimental and simulation results after the collision test for the HPF center pillar with PW and PS. Figure 9a,b show the top and side views of the center pillar, respectively, between the experiment and the simulation. The figure shows that the deformation behaviors of the experiment and the simulation were similar [20].

**Figure 9.** Comparison of the HPF center pillar with PW and PS after the drop weight test: (**a**) top and side view after the experiment; (**b**) top and side view after the simulation [20].

Figure 10 shows the comparison result of impactor load between experiment and simulation according to time. The maximum impact load of the experiment and simulation were 9.5 kN and 12.7 kN, respectively. The value of impulse and collision time between the experiment and simulation were 799 N·s, 0.165 s and 787 N·s, 0.117 s, respectively. Based on above results, the simulation and experiment were validated, and these material sections of mechanical properties were used for side crash simulation.

**Figure 10.** Comparison of the impactor load of the HPF center pillar with PW between the experiment and the simulation [20].
