*2.3. Side Crash Simulation*

2.3.1. Geometry and Properties of a Moving Deformable Barrier in a Sedan

A moving deformable barrier (MDB) was modeled for side crash simulation according to IIHS guidelines. Figure 4 shows the geometric modeling of an MDB with dimensions of <sup>450</sup> × <sup>1000</sup> × 650 mm3. The MDB consists of two parts: a main honeycomb block and an aluminum sheet used as the cover layer. The two parts were adhesively bonded together. The main honeycomb block was hexagonal in shape with a cell size of 22 mm made Al5052 foil. The foil thickness was 0.05 mm, with a crush strength of 31 MPa [21]. The weight of the MDB was 1360 kg ± 5 kg with a deformable element, and the center of mass was 1000 mm from the front of the deformable element, as shown in Figure 4. The MDB roll (*Ix*), pitch (*Iy*), and yaw (*Iz*) moments of inertia were 542 kg·m2, 2471 kg·m2, and 2757 kg·m2, respectively.

**Figure 4.** Geometric modeling of an MDB for side crash simulation.

Figure 5 shows the geometric modeling and material section of the automobile and pillars. The automobile geometry for used for simulation had the same dimensions as an automobile: 4580 × <sup>1820</sup> × 1250 mm3. As an actual automobile, the shell model was used, and the element type was set to S4 to reduce the hourglass effect and enable detailed measurement of absorbed energy. Owing to the complexity of the shape of the automobile, with curves and had many holes, the automobile part was meshed using a bottom-up mesh technique. The collision region was finely meshed, whereas regions away from the collision area were roughly meshed. The thicknesses of the center pillar, outer and inner reinforcement, and doors and other frames were 1.2 mm, 1.2 mm, and 2.0 mm, respectively. Multiple materials were used to design the sedan. The center pillar, PW, and frame and other parts were made with HPF with PS, HPF, and DP590 and CR420 (mild steel), respectively.

**Figure 5.** Geometry and material sections of the sedan for side crash test.
