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中文核心期刊

初始应力状态对材料层裂破坏特性影响研究

Study on spalling response of materials under pre-stress

  • 摘要: 通过对球面飞片加载条件下的应力/应变状态分析表明采用施加径向应变方法可以近似模拟球面加载的受力过程. 采用过盈配合的热装配方法对平面样品施加了径向预应变,一维平面应变气炮实验结果显示初始预应力(变)明显降低了LY12铝层裂强度. 从空洞长大基本原理出发分析了各向异性受力条件下空洞长大的路径和所消耗能量不同于各向同性应力加载.通过数值模拟对含损伤的材料本构模型进行分析,得到了材料层裂强度与其外部宏观应力场密切相关,也间接的与构型相关的结论.

     

    Abstract: The paper investigated the effect of pre-stress on thespalling of materials. Based on the deformation characteristic of sphericalspallation, pre-strain in the radial direction of LY12 plane sample was madeby heat assembly within excess conjugation. The spalling response of thesamples were tested by VISAR with one-dimensional gas-gun impact experimentsin different pre-strain states. The experimental results show that thepullback amplitudes of the free surface velocity and the spallation strengthof the samples obviously decrease in the pre-stress state under the sameimpact velocity. Moreover, numerical simulations were performed with thedamage constitutive model. The numerical results indicate that thespallation strength of materials have a strong relationship with theexternal stress fields, and indirect with the structures.

     

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