吸附塔支撑圈结构焊接残余应力有限元分析

Finite Element Analysis of Welding Residual Stress of Supporting Ring of Adsorption Tower

采用有限元分析软件Abaqus对吸附塔支撑圈结构焊接残余应力进行有限元分析,讨论了不同焊接热输入、焊后热处理温度、预热温度对焊接残余应力的影响规律。结果表明：在焊接接头角焊缝处产生了较大的纵向残余应力,这是引起疲劳失效的主要原因。焊接热输入越大,筒体外壁热影响区残余应力越大。焊后热处理能够有效降低残余应力。较高的预热温度有利于降低焊接残余应力,但预热温度也不能太高,应控制在150~200℃。为保证吸附塔支撑圈结构完整性,应综合考虑预热、焊接工艺及焊后热处理等因素,以充分降低焊接结构的残余应力。

The welding residual stress of supporting ring of adsorption tower was analysed by using finite element software Abaqus, and the effects of different heat inputs, postweld heat treatment temperatures and preheating temperatures on the welding residual stress were also discussed. The results show that big longitudinal residual stress are＇produced in comer weld of the joint, which is the main cause of fatigue failue. The bigger the heat input is, the bigger the residual stress in heat affected zone of the cylinder＇s outter wall is. The postweld heat treatment can effectively reduce residual stress. High preheating temperature is beneficial to reduce the welding residual stress, but the preheating temperature should not be too high, it should be controlled in 150-200 ℃. In order to ensure the structural integrity of the supporting ring of the adsorption tower, the preheating, welding process and postweld heat treatment should be considered comprehensively to reduce the residual stress of the welded structure.