不锈钢螺栓作为结构连接的重要构件已经部分应用在工程结构中，但目前关于该构件的疲劳设计缺乏科学系统的研究进而限制了其应用范围。本项目拟针对不锈钢螺栓及其连接件的疲劳性能和累计损伤机理展开研究。基于力控制方法设计出不同细节的不锈钢构件在常幅和变幅疲劳荷载作用下的疲劳试验，研究其疲劳性能，收集在不同拉应力、剪应力水平下的疲劳寿命数据，拟合与疲劳细节相对应的S-N曲线；通过调整应力比、预紧力和剪切面数量等参数评估其对疲劳性能的影响；基于三维应力应变场模拟，揭示不锈钢螺栓及其连接件在不同时间历程的应力应变分布特征，采用多种损伤算法和预测模型，探索疲劳裂纹的萌生、扩展规律以及破坏机理，以此建立不锈钢构件的疲劳风险初步预警机制；针对变幅荷载下的疲劳响应，采用累积损伤理论进行疲劳寿命和残余性能的估算；结合当前设计规范，提出针对不锈钢螺栓及其连接件的设计方法，为保障不锈钢材料在工程领域的应用提供科学支撑。

Stainless steel bolts have been partially applied in engineering practice as the critical component for structural connections, but the shortage of comprehensive academic studies on the fatigue design has limited the application range. This project thus aims to explore the fatigue performance and accumulative damage mechanism of stainless steel bolted connections. The fatigue tests of stainless steel bolted connections with different fatigue details under constant-amplitude and variable-amplitude loading will be proposed based on the force control method. The fatigue life corresponding to various tensile and shear stresses will be collected, and the related S-N curves will be fitted accordingly. Meanwhile, the effects of parameters including the stress ratio, the pretension and the number of shear planes will be assessed. Through the three-dimensional finite element modelling, the stress-strain distribution modes of stainless steel bolted connections under varied time histories will be revealed. Besides, the onset and evolution of fatigue crack as well as the fracture mechanism will be evaluated by means of different damage algorithms and models, which contributes to the setup of a preliminary early-warning system of fatigue risk for stainless steel bolted connections. The accumulative damage theories will be adopted to estimate the fatigue resistance and residual performance of stainless steel components under the variable-amplitude fatigue. Afterwards, the specific design method of stainless steel bolted connections will be put forward, which can be expected to prompt a broader application of stainless steel structures.