Extension of the Classical Laminate Theory for Fatigue Life Prediction

纤维增强复合材料的疲劳寿命预测目前在分析上是不可行的，因此设计工程师缺乏一种易于使用的计算工具或程序。在各种数学方法和实验研究出版物的基础上，仅给出了该主题的某些方面的答案，对基于非线性刚度退化的疲劳寿命预测模型的开始进行了深入的研究。由于工作载荷对FRP疲劳寿命的影响很大，因此在任意载荷和可变层叠顺序下的环境影响和结构设计预测尚未得到充分考虑。因此，主要的影响因素，如平均应力，载荷序列效应和层的多轴行为将被整合到当前的模型中，并通过灵敏度分析进行评估。验证将通过使用文献中的数据以及具体实验来进行。参考手册应该帮助设计工程师确定疲劳寿命的尺寸。实验测试指南将使所需数据的实验标准化。

The fatigue life prediction for fiber reinforced composites is currently analytically not viable hence the design engineer lacks an easy to use tool or routine for the calculation. On the basis of various publications on mathematical approaches and experimental investigations, giving only answers to some aspects of the topic, a thorough research was the platform for the onset of fatigue life prediction model on basis of non-linear stiffness degradations. Owing the great number of influences on the fatigue life of FRP through operating loads, environ-mental influences and structural design predictions for arbitrary loading and variable laminate stacking sequences are not completely considered yet. Therefore major influences as the mean stress, the load sequence effect and the multiaxial behavior of a layer will be integrated in the cur-rent model and evaluated via a sensitivity analysis. The validation will be carried out by using data from the literature as well as specific experiments. A reference manual is supposed to help the design engineer to dimension for fatigue life. A guideline for experimental testing will standardize the experiments for the required data.