Effect of the Opening/Closure of Microcracks on the Nonlinear Behavior of a 2D C-SiC Composite under Cyclic Loading
Effect of the Opening/Closure of Microcracks on the Nonlinear Behavior of a 2D C-SiC Composite under Cyclic Loading
复制标题
循环加载下微裂纹的张开/闭合对二维 C-SiC 复合材料非线性行为的影响
DOI：
10.1177/105678959800700404
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发表时间：
1998
影响因子：
4.2
通讯作者：
S. Baste
中科院分区：
文献类型：
--
作者：
J. Morvan;S. Baste
采用超声法和应变测量相结合的方法研究了二维陶瓷基复合材料在循环载荷作用下的非线性力学行为。该方法允许精确确定材料在拉伸应力下的刚度损失以及全局应变的哪一部分是弹性的或非弹性的。看来，在单调加载过程中的刚度损失主要是由于横向微裂纹密度和在循环加载过程中的复合材料的弹性响应的变化是这些裂纹的打开/关闭的结果。为了考虑这一影响，引入了一个内部变量，它代表了沿沿着累积的损伤。利用裂纹体有效性质的解析表达式，预测了二维C-SiC在单调和循环载荷作用下的非线性行为。裂纹密度和张开/闭合变量的本构关系描述了在循环荷载作用下的三维弹性变化以及沿整个试验沿着的非弹性应变。
The nonlinear mechanical behavior of a 2D ceramic matrix composite is investigated under cyclic loading by combined use of an ultrasonic method and strain measurements. This method allows the accurate determination of the loss of stiffness of the material under tensile stress and which part of the global strain is either elastic or inelastic. It appears that the loss of stiffness during monotonic loading is mainly due to transverse microcracks density and that the variation of the elastic response of the composite during cyclic loading is the result of the opening/closure of these cracks. In order to take this effect into account, an internal variable that represents the damage accumulated along the loading is introduced. By using the analytical expressions of the effective properties of a cracked solid, the nonlinear behavior of a 2D C-SiC is fully predicted under both monotonic and cyclic loading. The constitutive laws of the crack density and the opening/closure variable describe the three dimensional changes in elasticity under cyclic loading as well as the inelastic strains along the whole test.