含氦泡金属铝层裂响应的数值分析

因自辐照效应的影响，一些材料内部会产生大量的氦泡，关注这些氦泡对材料力学性能的影响是目前损伤破坏研究中的重要问题之一。结合相关文献的实验结果，采用耦合材料初始损伤、孔洞尺寸及惯性影响的损伤模型，对该问题进行了数值分析。结果显示:氦泡的内压及材料变形中温度的变化对损伤发展的影响很小；材料的初始损伤越大，材料内部应力减小得越快，损伤增长得越慢；因惯性的影响，初始氦泡越大，损伤增长相对较慢。因此，分析含氦泡材料的层裂损伤问题需要重点关注材料初始氦泡大小、初始损伤以及损伤演化过程中惯性的影响。

Numerical analysis of spall response in aluminum with helium bubbles

The creation of helium atoms is one of the main damaging mechanisms in neutron irradiated metals and is therefore a major concern in related scientific research.Recent researches under static loading conditions showed that the creation of helium atoms in metals is of great academic signifi cance,for their precipitation into bubbles can cause substantial deterioration of the mechanical properties of materials.In this paper,based on experimental results so far published,a damage model is adopted combining inertial effect,initial void size and damage,to investigate the influence of helium bubbles in aluminum on its dynamic spall properties.The numerical calculation results show that the damage growth is insensitive to the pressure inside the bubble and the temperature produced by plastic deformation;the inner stress decreases more quickly and the porosity increases more slowly with the increase of the initial damage;the damage increases more slowly with the increase of the initial size of the helium bubble due to the inertial effect.Therefore,the study on the spall response of metals with helium bubbles should focus on the initial size of the helium bubble,the initial damage and the inertial effect at high loading rates.