焊接工字梁应力集中的有限元分析

应力集中对焊接钢桥的疲劳寿命影响非常显著.为了研究焊接结构几何上的差异对焊趾应力集中系数的影响,通过有限元方法模拟结构的细部受力状态,计算出细部的应力集中系数,并分析了结构几何参数对应力集中系数的影响.对桥梁常用的工字形钢梁的横隔板与主梁翼板连接处的焊缝进行了细部有限元分析.结果表明:细部有限元网格尺寸不能取得过大,否则会影响应力集中系数的计算精度;底板厚度和横隔板厚度对焊趾应力集中系数的影响不大;焊脚长度和焊趾过渡圆弧半径对应力集中系数均有影响.

Finite element analysis on stress concentration of welded I-beam

Stress concentration has great influences on fatigue life of welded steel bridges. In order to study the stress concentration factors of weld toes influenced by the differences of structure geometry,the stress state of structure details was simulated by finite element ways,the stress concentration factor was calculated,and the influences of structural geometric parameters on the stress concentration factor were analyzed. The welding line of diaphragm plate and the main I-beam used commonly in bridges was analyzed using the finite element method. The results show that the dimension of finite element grid of details can not be too big,or it can influence the calculation precision; the thickness of bottom slab and diaphragm plate has little influence on the stress concentration factor; the welded feet dimension and the transition arc radius of weld toes have influences on stress concentration.