加载波形对钢桥典型构造细节疲劳性能的影响

摘要

对既有铁路钢桥构造细节进行梳理分析，选择十字形焊接接头、盖板端焊缝、U肋纵向角焊缝等典型的构造细节，研究其在不同加载波形条件下的疲劳性能。首先，根据三种典型构造细节在实桥中的受力特征和实验室加载条件，设计能够反映实桥受力特征的试件，建立有限元模型，验证试件设计的合理性，掌握试件的应力分布状态和应力集中程度。然后，开展矩形波和正弦波加载条件下三种典型构造细节的疲劳试验。最后，对三种典型构造细节的疲劳试验结果进行分析，掌握了加载波形对于构造细节疲劳性能的影响程度，可为我国铁路钢桥的设计和评估提供依据。%The details of welds in the existing steel railway bridges were summaried.Three typical welds including cross shaped weld,f lat end weld and longitudinal f illet weld on U rib.The fatigue behavior under different loading waveforms were stuied.First of all, test specimens were designed based on the stress status of the three welds in bridges and the loading conditions in laboratory.The f inite element model was established to validate the rationality of design and grasp the stress distribution and concentration.Next,the fatigue tests under the rectangular wave and sine wave loading condition were carried out on the three types of welds.Finally, the fatigue test results were analyzed,the loading waveform effects on fatigue behavior of three details were grasped.The results may provide the basis for the design and evaluation of China's railway steel bridge.