直驱永磁同步风力发电机支架主焊缝残余应力研究

摘要

针对风力发电机支架中主焊缝的焊接残余应力展开测量试验研究.选用MAG焊预制实际工况下40 mm厚的Q345D平板对接接头,按指定的焊接工艺规程完成多层多道焊接.焊接过程采用小孔法分别测试第4道、8道及12道焊后接头残余应力,测试结果表明纵向残余应力(σx)在焊缝中心区为残余拉应力峰值区,向母材方向逐渐减小,在远离焊缝中心的母材上为残余压应力;横向残余应力(σy)从焊缝中心区附近向母材一端残余拉应力由峰值逐渐减小.%In this paper,the welding residual stress of main weld-joint of the wind generator bracket was measured and studied.The butt joint of 40 mm-thickness Q345D plate in actual working condition was prefabricated by using the MAG welding according to the qualified welding procedure specification of multi-layer and multi-pass welding.In the welding process,the 4th,8th and 12th welded joint residual stress was tested by the blind-hole method.The test results show that the longitudinal residual stress reach peak area in the center of weld which is tensile stress,towards parent material tensile stress is gradually decreased,far away from the center of the weld residual stress is compressive stress.The transverse residual stress decreases from the peak of the tensile stress gradually.