基于疲劳模量的复合材料层合板疲劳寿命预测方法

Life Prediction Methodology for Composite Laminates Based on Fatigue Modulus

以碳纤维/树脂基T300/QY8911层合结构为研究对象,从唯象的观点出发,以疲劳模量为参量构造损伤函数,基于几组最典型的单向板疲劳试验数据,采用等寿命曲线和复合型累积损伤建立了单向板在多轴循环应力作用下的疲劳寿命模型。并以此为基础,发展了同种材料体系的任意铺层形式的多向层合板在复杂循环载荷作用下的疲劳寿命预测方法和计算程序,通过整合有限元平面应力分析、失效分析和材料性质退化模块模拟了多向层合板的疲劳失效过程。算例结果表明该方法可行、有效。

T300/QY8911 Carbon/Bismalimide laminate composite is taken as the research object to predict the fatigue life of laminate composite phenomenologically. Here, based on some typical fatigue test data, using fatigue modulus as a physical parameter to describe the basic fatigue behavior of unidirectional laminates, a fatigue damage model is presented for predicting the fatigue life of the unidirectional laminate composite under the multi-spindle cyclic stress, where normalized Goodman type diagrams and the method of compound cumulative damage variable are also applied. Further on, this research improves the method and procedure to predict under the complicated loading, the fatigue life of the multi-directional laminates composites of the same material in random laminates. At the same time, it simulates the fatigue and material property degradation damage process by integrating the finite rules. The result obtained shows that the element stress analysis, failure analysis, method is workable as well as effective.