# Ballistic Performance of 7A52/7A62 Aluminum Alloy Laminates: A Numerical Investigation of Configuration Effect

## TL;DR

This study uses simulations to show that 7A52/7A62 aluminum alloy laminates with specific layer arrangements offer better protection against ballistic impacts than single or double-layer plates.

## Contribution

The study introduces a novel configuration ranking for 7A52/7A62 laminates that significantly improves their energy absorption and ballistic resistance.

## Key findings

- Four-layer laminates outperform monolithic and double-layer plates in ballistic performance.
- The ABAB stacking sequence achieves the lowest residual projectile velocity of 256 m/s.
- Multi-interface delamination and plastic deformation enhance energy absorption efficiency.

## Abstract

This study presents a systematic numerical investigation into the ballistic performance of 7A52/7A62 aluminum alloy laminated plates with varying configurations. The dynamic mechanical behavior of the base alloys, 7A52 and 7A62, was first characterized experimentally, and the corresponding Johnson-Cook (J-C) constitutive parameters were calibrated. Using the calibrated J-C model, a series of numerical simulations were performed on several structural configurations, including single-layer (7A52-A, 7A62-B), double-layer (AB, BA), and four-layer laminates (ABAB, BAAB, ABBA, BABA). The results demonstrate that four-layer laminates exhibit markedly better ballistic performance than monolithic and double-layer plates. Among them, the ABAB stacking sequence—arranged in an alternating soft–hard–soft–hard pattern—shows the optimal performance, yielding a residual projectile velocity of only 256 m/s. This represents an approximately 27% reduction compared to the monolithic high-strength 7A62 plate. The overall ranking of ballistic performance is as follows: ABAB > BAAB > ABBA > BABA. Energy-based analysis further indicates that multi-interface delamination, coupled with plastic deformation and damage evolution, improves the energy-absorption efficiency of the laminated plates and thus enhances their ballistic resistance. This study offers valuable guidance for the lightweight design of laminated 7XXX-series aluminum alloy protective plates.