With new energy vehicles developing rapidly, battery safety, as an important part
of the impact on the range of new energy vehicles and vehicle safety, has become
the focus of attention. The battery pack protection plate is a core component to
protect the battery, its performance needs not only impact resistance, but also
lightweight, honeycomb sandwich structure with its excellent energy absorption
characteristics and weight reduction performance by the battery pack protection
plate performance research. At present, the core-to-face sheet interaction in
conventional sandwich structures subjected to impact loads has not been fully
elucidated, and the quantitative characterization of damage is insufficient, so
this paper aims to optimize the lightweight impact-resistant structure by
exploring the synergistic energy dissipation mechanism between the high-strength
core material and the steel plate. The study combines theory and simulation,
adopting ideal rigid-plastic film theory to establish a critical response model
to predict the structural failure threshold, equivalent single-layer theory to
simplify the analysis of plywood, and a stiffness matrix model to quantify the
structural mechanical contribution of each layer. A two-material synergistic
design framework is proposed by fully considering the material properties and
adopting the corresponding intrinsic structure and failure criteria for
different materials. Analysis reveals that geometric confinement is a key
characteristic of the honeycomb sandwich panel’s response and a strain gradient
driving mechanism at low impact resistance, and a new energy distribution
paradigm is found through the analysis of the energy absorption ratio. The
theoretical and simulation results are in great agreement with each other, which
just has a difference of 0.7% in the peak force, 1.4% in the critical
displacement error, and less than 2% in the impulse integration error. The
proposed dual-material co-design framework provides a solution for electric
vehicle battery protection systems that balances lightweight and impact
resistance.