摘要
本文通过对MQ16—30型门机主臂架在吊重下工作应力、焊接残余应力及抗局部失稳的临界应力的计算结果及分析,指出了额定起重量16t的MQ16—30型门机在初次吊重9t的工况下主臂架发生弯折导致整机失效事故的原因。即焊接残余应力与工作应力叠加大于抗局部失稳的临界应力。
Through calculating and analysing loading stress, welding residual stress and critical stress of the main boom for the MQ16—30 gantry crane,this paper explains the cause why the main boom so bends, when lifting 9 ton weight at the first time that the crane fails. The reason is that the sum of welding residual stress and loading stress is larger than critical stress.
关键词
焊接
残余应力
门式起重机
welding residual stress
loading stress
local stability
critical stress
