泡沫铝合金动态弹塑性本构关系的研究(英文)

Elasto-plastic constitutive model of aluminum alloy foam subjected to impact loading

提出一个多参数的非线性弹塑性唯象本构模型,该模型能够全面地描述泡沫铝合金的典型三阶段变形特征,即线弹性阶段、应力平台阶段和密实化阶段。考虑到密度(相对密度)是泡沫铝这类多孔材料性能表征的最重要参数,在对泡沫铝合金进行各种应变率下的单向压缩实验基础上,确定模型中的参数与相对密度的函数表达式,从而,该模型能系统地描述相对密度、应变率效应对其动态力学行为的影响。模型预测结果和实验结果的对比验证了该模型的可靠性。研究结果可为吸能缓冲及防护结构的优化设计提供技术参考。

A multi-parameter nonlinear elasto-plastic constitutive model which can fully capture the three typical features of stress-strain response, linearity, plasticity-like stress plateau and densification phases was developed. The functional expression of each parameter was determined using uniaxial compression tests for aluminum alloy foams. The parameters of the model can be systematically varied to describe the effect of relative density which may be responsible for the changes in yield stress and hardening-like or softening-like behavior at various strain rates. A comparison between model predictions and experimental results of the aluminum alloy foams was provided to validate the model. It was proved to be useful in the selection of the optimal-density and energy absorption foam for a specific application at impact events.