基于MIDAS/Civil的既有桥梁温度应力有限元分析

温度应力是大型桥梁结构开裂的重要影响因素之一。以既有典型桥梁为背景,参考我国公路桥梁设计规范,采用通用有限元程序MIDAS/Civil对该桥温度效应进行仿真分析,得到截面温度梯度和体系温变对该桥应力的影响规律,然后将截面温度梯度和体系温变进行线性组合,探讨它们对大桥内力的影响,并与实际检测的桥梁裂缝分布进行对比。同时,从理论角度计算得到跨中截面最大的弯矩与软件计算结果甚为接近,从而验证了软件计算的合理性,其有限元模拟得到的结论对该桥的维修加固及同类型桥梁的结构设计具有一定参考价值。

Finite Element Analysis on Thermal Stress of In-Service Bridge Based on MIDAS/Civil

Thermal stress is an important influencing factor of large bridge structure cracks. Taking a typical bridge as an example, through consulting the design criterions of highway bridge of China, the simulation analysis on the temperature effect of the bridge is implemented using the general finite element program MIDAS/Civil. Through that, the rule of the influence of section temperature gradient and system temperature change on the bridge stress is got. With the linear combination of section temperature gradient and system temperature change, their influence on the bridge＇s internal force is discussed, which is contrasted with the detected actual distribu- tion of cracks. Meanwhile the maximum bending moment at mid-span section calculated by theoretical method isvery close to the result computed by software, which validates the rationality of software computation. The conclu- sion from finite element simulation has a certain reference value to the maintenance of this bridge and the struc- tural design of similar bridges.