In the field of automotive safety, head injury in crash test dummies is a critical indicator for evaluating collision safety performance. Under current standards, excessive head injury resulting from impacts with hard surfaces has drawn widespread attention. Based on experimental results, this study analyzes why the conventional approach of using thickened foam to reduce head injury is no longer effective and proposes a new design concept: avoiding any hard objects in the head impact area and minimizing obstructions to the dummy head’s curved motion along the seatback to reduce head injury values.
Traditionally, thickened foam has been used to reduce peak acceleration experienced by the dummy’s head during a collision. However, experimental results show that when the head impacts the seatback at higher velocities, the current thickened foam design fails to meet safety requirements. This study aims to propose a new design approach to control dummy head injuries, further enhancing automotive safety performance.
Experimental results indicate that head impact velocity is one of the main factors causing excessive dummy head injury. When the collision speed reaches 50 km/h, the dummy’s head impacts the seatback at a relatively high speed. While increasing foam thickness can reduce the peak acceleration, any hard objects within the foam increase the acceleration pulse duration. As a result, the calculated Head Injury Criterion (HIC) may exceed the standard limit. Therefore, new design approaches are needed to reduce head injury values.
To lower dummy head injury values, the new design concept focuses on avoiding any hard objects in the head impact area and minimizing obstacles to the head’s curved motion along the seatback. Specific measures include:
In designing the head impact area, all potential hard objects that could cause injury must be eliminated. This involves careful selection of materials and structural design to ensure the seatback surface is smooth and free of protrusions.
To reduce resistance to the head’s curved motion, the following measures can be applied:
Optimize Seatback Curvature: Design the seatback with precise contours so the head can move along a smooth curved path during impact, minimizing friction and resistance.
Reduce Seatback Thickness: Excessive seatback thickness increases the contact area with the head, raising resistance during impact. Appropriately reducing thickness can lower head injury risk.
The feasibility and effectiveness of the new design concept can be verified through both computational simulations and physical testing.
Computational Simulation: Computer-Aided Engineering (CAE) software can evaluate different design schemes and optimize design parameters.
Physical Testing: Laboratory or full-scale crash tests can compare head injury values under different designs, allowing assessment of the effectiveness of the new approach.
