<p>Supporting information data.</p>

Fatigue failure in composite polymer materials has attracted the attention of numerous researchers due to the extensive range of applications for these materials in aerospace, automotive, and biomedical industries. In this study, E-Glass fiber chopped strand mat was laminated with Epoxy LR625 using the vacuum bagging technique (VBT). We examined mode I fatigue crack growth related to translaminar failure in chopped strand mat-reinforced resin composite laminates through both experimental and numerical methods, utilizing the extended finite element method and direct cyclic approach. The main finding of this research is determining Paris coefficients of composite polymer material, fiberglass chopped strand mat/epoxy, fabricated by VBT with translaminar cracks. Paris law constants, C and m, were determined to be 4 × 10 ⁻ ¹² and 4.8584, respectively. The results obtained from both experimental and extended finite element method (XFEM) models of fatigue life are in good agreement, with a 6% error in predicted fatigue life. This research provides the determination of the Paris coefficients, which serve as a correction between fatigue and fracture mechanics for the composite materials. The growth of fatigue cracks can be characterized by the relationship between the crack propagation rate during each loading cycle and the fluctuations in the stress intensity factor (SIF).

聚合物基复合材料的疲劳失效问题，因该类材料在航空航天、汽车及生物医学产业中的广泛应用，已受到众多研究者的广泛关注。本研究采用真空袋成型工艺（VBT），将E玻璃纤维短切毡与环氧树脂LR625进行层压制备试样。本研究通过实验与数值模拟相结合的方法，利用扩展有限元法（extended finite element method, XFEM）及直接循环法，探究了短切毡增强树脂基复合材料层合板中与穿层失效相关的I型疲劳裂纹扩展行为。本研究的核心成果为确定了采用真空袋成型工艺制备、带有穿层裂纹的玻璃纤维短切毡/环氧树脂聚合物基复合材料的帕里斯（Paris）公式系数。帕里斯定律的常数项C与m分别为4×10⁻¹²和4.8584。疲劳寿命的实验结果与扩展有限元法（XFEM）数值模拟结果吻合良好，预测疲劳寿命的误差仅为6%。本研究确定的帕里斯公式系数，可作为该复合材料疲劳与断裂力学研究间的修正参考。疲劳裂纹的扩展行为可通过每一次加载循环中的裂纹扩展速率与应力强度因子（SIF）波动之间的关系进行表征。