Probabilistic anisomorphic constant fatigue life diagram approach for prediction of P–S–N curves for woven carbon/epoxy laminates at any stress ratio
Probabilistic anisomorphic constant fatigue life diagram approach for prediction of P–S–N curves for woven carbon/epoxy laminates at any stress ratio
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DOI：
10.1016/j.compositesa.2015.10.021
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发表时间：
2016
影响因子：
8.7
通讯作者：
M. Kawai;K. Yano
中科院分区：
文献类型：
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作者：
M. Kawai;K. Yano
针对平纹织物碳/环氧层合板，提出了一种通用的工程方法来构造以失效概率为参数的各向异性常数疲劳寿命（CFL）图族，从而有效地预测任意应力比下的P-S-N曲线。首先进行等幅疲劳试验，分别获得不同应力水平和应力比下的疲劳寿命统计样本。还收集了静态拉伸和压缩强度数据。Kolmogorov-Smirnov和Anderson-Darling拟合优度检验表明，在5%的显著性水平下，双参数对数正态分布和Weibull分布分别可用作静态强度和疲劳寿命数据的分布。然后，我们试图开发一种方法，有效地建设不同的常数值的故障概率的各向异性CFL图。它需要临界应力比分布的任何百分位点的P-S-N曲线。为了达到这一要求，概率标度法制定。它考虑了临界应力比的失效概率依赖性和临界应力比的P-S-N曲线的应力比依赖性。最后，使用所提出的方法预测不同的常数值的故障概率的各向异性CFL图，它们被证明是与实验结果吻合得很好。结果表明，本文提出的概率各向异性CFL图方法可以有效、准确地预测编织CFRP层合板在任意应力比下的P-S-N曲线。
A general engineering methodology to construct a family of anisomorphic constant fatigue life (CFL) diagrams with probability of failure as the parameter that allows efficiently predicting P–S–N curves at any stress ratios is developed and validated for a plain weave fabric carbon/epoxy laminate. Constant amplitude fatigue tests are first performed to obtain statistical samples of fatigue life at different stress levels and stress ratios, respectively. Static tensile and compressive strength data are also collected. The Kolmogorov–Smirnov and Anderson–Darling goodness-of-fit tests suggest that both two-parameter lognormal and Weibull distributions are acceptable as the distributions for the static strength and fatigue life data, respectively, at the significance level of 5%. Then, we attempt to develop a methodology for efficient construction of the anisomorphic CFL diagrams for different constant values of probability of failure. It requires the P–S–N curves for any percentile points of the distribution for the critical stress ratio. To come up with this requirement, a probabilistic scaling law is formulated. It takes account of the probability-of-failure dependence of the critical stress ratio and the stress-ratio dependence of the P–S–N curve for the critical stress ratio. Finally, the anisomorphic CFL diagrams for different constant values of probability of failure are predicted using the proposed methodology, and they are shown to be in good agreement with the experimental results. It is also demonstrated that the P–S–N curves can efficiently and accurately be predicted for the woven CFRP laminate at any stress ratios using the proposed probabilistic anisomorphic CFL diagram approach.