Considered are two types of multistage cyclic block loading rather common in the practice of fatigue tests and fatigue life predictions for layered polymer composite materials: block loading by four-stage cyclic regular zero-tension loads and block loading by multistage (8-10 levels) asymmetric cyclic loads. In order to improve the prediction accuracy for the fatigue life of carbon-fiber-reinforced plastics under such loadings, special nonlinear fatigue damage accumulation models are proposed. Elaborated are methods for predicting the fatigue life of carbon-fiber-reinforced plastics by the models proposed. The prediction methods are verified by the example of T800/5245 and AS4/3501-6 carbon-fiber-reinforced laminates. A relatively high accuracy of fatigue life predictions for the laminates was obtained as compared with that given by prediction methods using the Palmgren–Miner rule.

中文翻译：

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层状复合材料循环块载荷下非线性疲劳损伤累积模型

在层状聚合物复合材料的疲劳试验和疲劳寿命预测的实践中，考虑了两种类型的多阶段循环块加载：四阶段循环规则零张力加载块加载和多阶段块加载（8-10级）不对称循环载荷。为了提高此类载荷下碳纤维增强塑料疲劳寿命的预测精度，提出了特殊的非线性疲劳损伤累积模型。详细阐述了通过所提出的模型预测碳纤维增强塑料疲劳寿命的方法。预测方法以T800/5245和AS4/3501-6碳纤维增强层压板为例进行验证。