基于热点应力法的正交异性钢桥面板疲劳验算

摘要

为了解决正交异性钢桥面板的疲劳开裂问题,提出将热点应力法应用于其疲劳验算.该方法采用ANSYS子模型模块,通过国际焊接协会的线性外推方法,计算获得验算部位的热点应力.基于热点应力法给出正交异性钢桥面板的疲劳验算流程,对验算涉及的问题结合甬江桥实例进行了探讨.研究结果表明:与名义应力法相比,热点应力法可以反应正交异性钢桥面板疲劳开裂的实质；利用热点应力法对甬江桥正交异性钢桥面板加劲肋与横隔板连接部位的加劲肋进行疲劳验算,得出该构造细节的疲劳寿命为73 a.%The hot spot stress method was applied to fatigue assessment to solve the problem of fatigue cracking in orthotropic steel bridge deck.In this method,the hot spot stresses at check positions were calculated using the linear extrapolation method of International Institute of Welding and the ANSYS sub-model method.Based on hot spot stress method,the process of fatigue assessment for orthotropic steel bridge deck was provided,and the related problems were investigated in a case study on Yongjiang railway cable-stayed bridge.The results show that compared with the nominal stress method,the hot spot stress method can better reflect the cracking essence of orthotropic steel bridge decks.The fatigue assessment made for the rib located at the joint between diaphragms and the rib of the orthotropic steel bridge deck of the Yongjiang bridge reveals that the fatigue life span of the structure is 73 years.