Multi-Material Front Structures: A Pathway to Safer and More Sustainable Vehicle Design

Frontal crash structures play a vital role in occupant safety, but traditional designs often involve a trade-off between structural strength and weight efficiency. In the pursuit of safer and more sustainable mobility, this study explores a physics-based methodology that leverages the principle of dynamic equilibrium to guide the integration of dissimilar materials in front-end vehicle structures. Specifically, we examine a novel configuration wherein aluminum High pressure die cast (HPDC) is introduced in swan neck region of the front longitudinal member, while retaining steel in the frontal crush zone. This arrangement aims to redistribute crash loads and control deformation mechanisms, enabling improved energy absorption without compromising structural integrity. To evaluate the proposed strategy, a series of detailed finite element simulations were conducted using LS-DYNA, a widely adopted tool for vehicle crash analysis. The results reveal that the dynamic equilibrium approach offers a rational and efficient framework for material allocation, allowing for the optimization of crash performance metrics while simultaneously achieving weight reduction. Compared to conventional all-steel or all-aluminum designs, the hybrid structure demonstrate efficient, improved crashworthiness, with measurable mass savings. By grounding material decisions in mechanical principles rather than empirical iteration, this research presents a scalable methodology applicable to a wide range of vehicle platforms. The outcomes offer a compelling case for the adoption of multi-material architectures as a pathway toward enhanced crash safety and reduced environmental impact. This work contributes to the broader vision of SIAT 2026 by showcasing how fundamental engineering mechanics can drive innovation in vehicle safety systems while supporting global goals for lightweight and sustainable mobility solutions.