Yang Jingwen, Wang Shuai, Lu Hongli, Yuan Zhiwei, Mu Xiaokai, Sun Qingchao, Yuan Bo
School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
Beijing Institute of Astronautical Systems Engineering, Beijing 100076, China.
Polymers (Basel). 2025 May 17;17(10):1382. doi: 10.3390/polym17101382.
Fiber-reinforced polymer (FRP) composites are widely utilized in aerospace and shipbuilding due to their outstanding mechanical properties and lightweight nature. During prolonged service, the mechanical performance of composite bolted joints has drawn increasing attention. This study integrates experimental, theoretical, and numerical methods to simulate compressive creep and clarify preload relaxation mechanisms in these joints. A non-stationary Burgers model is proposed to describe the compressive creep behavior of FRP composites and metals, implemented in ABAQUS, which improves fitting accuracy by approximately 10% in compared to the classical model. Two types of creep tests were conducted to examine the effects of initial load and material type on creep behavior, with model accuracy validated against experimental data. Finite element analysis (FEA) was further employed to assess the impact of localized loading and structural parameters on strain. The results demonstrate that the viscoelastic behavior of materials is the dominant factor contributing to preload relaxation in composite bolted joints. Under localized loading conditions, the maximum creep strain can be reduced by more than 60%, effectively mitigating preload loss. This study provides a robust framework for predicting preload relaxation, offering valuable insights for composite bolted joint design.
纤维增强聚合物（FRP）复合材料因其优异的机械性能和轻质特性而广泛应用于航空航天和造船领域。在长期服役过程中，复合材料螺栓连接的力学性能受到了越来越多的关注。本研究综合运用实验、理论和数值方法来模拟压缩蠕变，并阐明这些连接中的预紧力松弛机制。提出了一种非平稳伯格斯模型来描述FRP复合材料和金属的压缩蠕变行为，并在ABAQUS中实现，与经典模型相比，拟合精度提高了约10%。进行了两种类型的蠕变试验，以研究初始载荷和材料类型对蠕变行为的影响，并根据实验数据验证了模型的准确性。进一步采用有限元分析（FEA）来评估局部加载和结构参数对应变的影响。结果表明，材料的粘弹性行为是导致复合材料螺栓连接中预紧力松弛的主要因素。在局部加载条件下，最大蠕变应变可降低60%以上，有效减轻预紧力损失。本研究为预测预紧力松弛提供了一个强大的框架，为复合材料螺栓连接设计提供了有价值的见解。
