Notch‐Sensitivity of Fiber‐Reinforced Ceramic‐Matrix Composites: Effects of Inelastic Straining and Volume‐Dependent Strength
Notch‐Sensitivity of Fiber‐Reinforced Ceramic‐Matrix Composites: Effects of Inelastic Straining and Volume‐Dependent Strength
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DOI：
10.1111/j.1151-2916.1999.tb01899.x
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发表时间：
2004-12
影响因子：
3.9
通讯作者：
J. McNulty;F. Zok;G. Genin;A. Evans
中科院分区：
文献类型：
--
作者：
J. McNulty;F. Zok;G. Genin;A. Evans
研究了圆孔和锐缺口对两种尼龙增强陶瓷复合材料拉伸强度的影响。非弹性应变对应力再分布的影响已阐明通过测量的局部应变在高应力集中的区域，再加上有限元模拟的测试几何形状，使用非线性本构关系适合于陶瓷复合材料。强度的尺度依赖性已从对不同尺寸的试样进行的试验中推断出来。两个故障模型，将非弹性应变和规模依赖的效用进行了评估：一个基于点应力失效准则和其他最薄弱环节的断裂统计。这两种方法提供了一个合理的一致的描述的实验测量。一些与故障模型的影响和限制进行了讨论。
The effects of circular holes and sharp notches on the tensile strength of two Nicalon-reinforced ceramic composites have been investigated. The influence of inelastic straining on the redistribution of stress has been elucidated through measurements of the local strains in the regions of high stress concentration, coupled with finite element simulations of the test geometries, using a nonlinear constitutive law appropriate to ceramic composites. The scale dependence of strength has been inferred from tests performed on specimens of varying size. The utility of two failure models that incorporate both the inelastic straining and the scale dependence has been assessed: one based on the point stress failure criterion and the other on weakest-link fracture statistics. Both approaches provide a reasonably consistent description of the experimental measurements. Some of the implications and limitations associated with the failure models are discussed.