Practical applied components made of Fiber-Reinforced Plastics (FRPs) are usually subjected to cyclic loading with variable load amplitudes and arbitrary load orientation in the course of their service life. For a cost-effective design process of composite structures, it is essential to use computationally efficient and detailed fatigue damage design tools. This contribution focuses on the extension and application of a progressive Finite-Element-based Fatigue Damage Model (FDM) for unidirectional FRPs for lifetime prediction under different block loading conditions. The employed FDM relies on a layer- and energy-based approach, and it is capable of including basic fatigue phenomena such as load sequence effects and stress redistributions. First, the damage evolution laws on which the FDM is based are extended to block loading conditions with arbitrary load sequences. The effects of passive damage, which occur in this context under alternating cyclical tensile and compressive loading, are also taken into account. Secondly, appropriate block loading patterns are defined for the numerical prediction of the lifetime. Finally, the calculation results are presented and critically evaluated based on experimental findings from literature. The comparison of simulations with experiments demonstrates the high predictive capacity of the presented FDM.

由纤维增强塑料（FRPs）制成的实际应用组件通常会在其使用寿命过程中经受周期性变化的负载，这些负载具有可变的负载幅度和任意的负载方向。对于复合结构的经济有效的设计过程，必须使用计算效率高且详细的疲劳损伤设计工具。该贡献集中于单向FRP的基于渐进式有限元疲劳损伤模型（FDM）的扩展和应用，以预测不同块载荷条件下的寿命。所采用的FDM依赖于基于层和能量的方法，并且能够包含基本的疲劳现象，例如载荷序列效应和应力重新分布。第一的，FDM所基于的损伤演化定律被扩展为阻止具有任意载荷序列的载荷条件。还考虑了在这种情况下在交替的周期性拉伸和压缩载荷下发生的被动损伤的影响。其次，为寿命的数值预测定义适当的块加载模式。最后，给出了计算结果并根据文献中的实验结果进行了严格评估。仿真与实验的比较证明了所提出的FDM具有很高的预测能力。为寿命的数值预测定义了适当的块加载模式。最后，给出了计算结果并根据文献中的实验结果进行了严格评估。仿真与实验的比较证明了所提出的FDM具有很高的预测能力。为寿命的数值预测定义了适当的块加载模式。最后，给出了计算结果并根据文献中的实验结果进行了严格评估。仿真与实验的比较证明了所提出的FDM具有很高的预测能力。