In the automotive industry, short fiber reinforced plastic (SFRP) composites are important alternatives to metallic materials to improve fuel efficiency and reduce environmental problems. Vehicle components have geometrical discontinuities such as holes and weld lines subject to stress under cyclic loading. In this study, the fatigue behavior of SFRP composites was analyzed to explore the notch effect. Fiber orientation during the injection molding process was one of the major factors affecting the mechanical properties of SFRP composites. The use of Digimat with mean-field homogenization methods enabled description of the micro-structure, including fiber length and fiber orientation, and offered diverse options for modeling the linear and nonlinear SFRP materials. The fatigue notch effect of fiber reinforced polybutylene terephthalate with 30 wt% glass fiber was searched to provide references. LS-DYNA, a commercial finite element code, was used in coupled analysis with Digimat to calculate the stress amplitude of SFRP composites according to fiber orientation. The stress results from a structural analysis were used for fatigue analysis with FEMFAT. Fatigue analysis for the SFRP composites took into account influence factors like the relative stress gradient and fiber orientation.

在汽车行业，短纤维增强塑料 (SFRP) 复合材料是金属材料的重要替代品，可提高燃油效率并减少环境问题。车辆部件具有几何不连续性，例如在循环载荷下承受应力的孔和焊缝。在这项研究中，分析了 SFRP 复合材料的疲劳行为以探索缺口效应。注射成型过程中的纤维取向是影响SFRP复合材料力学性能的主要因素之一。将 Digimat 与平均场均化方法结合使用，可以描述微观结构，包括纤维长度和纤维取向，并为线性和非线性 SFRP 材料建模提供多种选择。研究了含30wt%玻璃纤维的纤维增强聚对苯二甲酸丁二醇酯的疲劳缺口效应，以提供参考。LS-DYNA 是一种商业有限元代码，用于与 Digimat 进行耦合分析，以根据纤维取向计算 SFRP 复合材料的应力幅值。结构分析的应力结果用于 FEMFAT 的疲劳分析。SFRP 复合材料的疲劳分析考虑了相对应力梯度和纤维取向等影响因素。