极小曲面力学超材料抗冲吸能特性分析

本文基于极小曲面结构构建了一类力学超材料,并研究了其准静态及动态力学特性.首先,通过对等效密度为30%、40%和50%的超材料样件进行准静态压缩试验,分析了不同等效密度下结构准静态力学特性变化规律,结果表明,结构模量及平台应力随等效密度的增长呈指数上升,其变化规律可用Gibson-Ashby模型进行精准拟合；其次,研究了不同冲击工况对极小曲面力学超材料动态力学特性的影响规律.根据动态力学特性影响因素及变化规律,分别构建了刚性-完美塑性-锁定模型和简化吸能特性预测模型,对冲击时的力学超材料强度及吸能特性进行预测.结果表明,基于三周期极小曲面的力学超材料具有良好的抗压抗冲吸能特性,且其动态力学性能可以通过建立的模型进行精确预测,为高性能防护结构设计提供了理论基础.

Impact Resistance and Energy Absorption of Mechanical Metamaterials with Minimal Surfaces

Based on triply periodic minimal surfaces structures, the Gyroid type mechanical metamaterials are proposed, and the quasi-static and dynamic properties of the proposed structure are investigated. Firstly, the quasi-static compression tests of the Gyroid structure with the relative density of 30%, 40% and 50% are performed to investigate the effect of the density on quasi-static mechanical properties. Results found that, the structure modulus and average plateau stress increase exponentially with the increase of equivalent density, and Gibson-Ashby model is used to predict the change rules. Then, the influence of dynamic loadings on mechanical response of minimal surfaces mechanical metamaterials is investigated. According to the influence factors and variation tendence, the rigid-perfectly plastic-lock model and simplified prediction model of energy absorption are conducted to predict the crushing strength and energy absorption of gyroid structures under dynamic impact. This work demonstrated that, the mechanical metamaterials based on triply periodic minimal surface structure possess prominent load bearing and impact resistance capability, and the key performance can be predicted by the theoretical model, which provide theoretical foundation of the design of high performance protective structure.