【摘要】 海洋平台轴承座结构具有焊缝多且分布比较集中、采用多种高强钢、各构件厚度差异大、整体尺寸大、焊缝拘束大等特点,焊接易造成该结构高幅值且分布复杂的残余应力.文中综合应用结构简化、带状热源、焊道合并等多种方法,对海洋平台轴承座结构的焊接残余应力分布进行高效预测;并根据实际尺寸制造模拟件,测试该模拟件的应力来验证计算结果;结合计算结果分析了该结构焊接应力集中区域产生的原因,最终运用高效计算方法优化了该结构的焊接顺序,并改善了该结构中危险焊缝的应力状态.分析结果表明:多构件复杂结构焊接时,小刚度构件在易变形的方向上受到其他焊缝收缩产生的弯矩作用是造成结构局部焊缝应力集中的主要原因,调整焊接顺序可以有效避免局部区域的应力集中.更多还原

【Abstract】 The bearing structure on the offshore platform is made by welding of multiple members with different steel grades and different thicknesses. It contains multiple and intensive weld seams and has the features of large overall size and large restraints acting on weld seams. The welding can induce high magnitude and complex residual stresses in the structure. Several efficient methods such as structure simplification, segmental heat source, and lumped-pass method were combined to efficiently predict the welding residual stresses in the bearing structure. A mockup of the bearing structure was manufactured and the stresses in the mockup were measured to verify the simulated results. The reason that caused the stress concentration was discussed and thereby the welding sequence was optimized by means of the proposed efficient simulation method. The results show that the main reason of stress concentration in the welding region of the low-stiffness member is the bending moment induced by the shrinkage of subsequent welds acting on the low-stiffness member in the direction of easy deformation.更多还原