Mechanism and Optimization of Quasi-Static Compression Performance in Hexagonal Honeycomb Sandwich Structures.

Lightweight load-bearing components are critical for advancing aerospace engineering, where hexagonal honeycomb sandwich structures have emerged as a preferred solution due to their exceptional strength-to-weight ratio. However, the synergistic regulation mechanism of geometric parameters on their quasi-static compression performance remains incompletely understood, and the lack of efficient multiobjective optimization frameworks hinders the balance between load-bearing capacity and lightweight design. Herein, we establish and validate a high-fidelity nonlinear finite element model to systematically characterize the effects of cell edge length, cell wall thickness, core height, and face sheet thickness on compression behavior, failure modes, and energy absorption characteristics. A multiobjective optimization framework based on the Whale Optimization Algorithm (WOA) is developed, with cell edge length and wall thickness identified as the dominant design variables. Quantitative analysis reveals that these two parameters contribute over 85% to the variation in peak load, and the scaling law F max ∝ t 3/L 2 is experimentally verified for this configuration. The resulting Pareto-optimal solution set defines three distinct design regimes tailored to different aerospace engineering requirements. Quasi-static compression tests on the optimized balanced configuration demonstrate a peak load prediction error of only 6.4%, confirming the reliability of the proposed framework. This work establishes a systematic design methodology for lightweight honeycomb sandwich structures under quasi-static compression conditions, providing a fundamental reference and research basis for the performance optimization of aerospace load-bearing components. The extrapolation of the current conclusions to dynamic service scenarios such as impact and fatigue requires further dedicated investigation.