The Welding Stress Numerical Simulation Of Orthotropic Steel Bridge Deck

Orthotropic steel bridge deck as one kind of structure with light weight, ultimate bearing capacity, low height of the main beam, manufacturing quality and precision is controllable, short construction period etc., is application to a number of large and medium span bridges. Most orthotropic steel bridge decks are connected by welding, this kind of connection lead to complex welding residual stress, which reduces the proportional limit of the material, weakened the materials’anti-fatigue, anti-corrosion and other properties. Now, the technology of control and elimination the residual stress is not mature, residual stress still left in the structure. To ensure the safety and reliability of structure, accurately infer the residual stress distribution is a very important task.After studying former research, this thesis try another method to study the welding of Orthotropic steel bridge decks’roof and U rib by finite element software ANSYS:(1)Based on actual welding process, the orthotropic bridge deck with double layer welds model (roof:16mm thick; U rib:8mm thick) was established;(2)The thermo-physical parameters and mechanical parameters of Q345qD in high-temperature condition were Determine;(3)Welding heat source model was determined; to simulate weld zone growth over time and control the heat source moving, APDL was compiled; at last, welding temperature was calculated;(4) By the use of APDL command, temperature results were called and welding stress distribution was calculated.This thesis summarized the theory and method of simulation welding temperature and stress, calculated the welding of orthotropic bridge deck. We can draw the following conclusions:It is feasible to use ANSYS to calculate welding temperature and stress; after welding, there are welding residual stress with the summit119.5MPa on the deck, we must pay sufficient attention in design. By the use of APDL command, we can just change a few of parameters in the macro file to simulate different welding process, like welding current, voltage, welding speed. By this way, we can chose the optimum welding process.