点焊拼接板成形性能的研究

作为拼焊板的一种,点焊拼接板在变形加工时所表现的各种成形特性都源自于焊点对基板力学性能的影响。采用力学平衡等效原理推导出了双层板的等效弹塑性性能参数,并采用应力参数法研究了焊点引起的应力集中现象。研究表明:焊点的存在影响了板料的局部应力分布,当焊点之间距离过小时,热影响区的交互作用变大,可能导致焊点处的应力集中加剧,易出现微裂纹,使其疲劳寿命下降。随着焊点距离的增大,热影响区的交互作用迅速降低,但其强度和刚度随焊点的强化效应也相应减弱。

Investigation on Forming Properties of Patch Type TWB

As a kind of tailored-welded blanks,its various deformation features also arise from the influences of welding spot on the mechanical properties of the base blank.In combination with test results,the micro-mechanism of the local strengthening of welding-spot is explained.The equivalent elastic-plastic performance parameters of double layer blank are induced using mechanical equilibrium equivalent principle,and stress concentration phenomenon caused by the welding-spot is studied adopting stress function method.The results indicate that the presence of the welding-spot has an influence on the local stress distribution of metal sheet.The smaller the distance between welding-spots is,the stronger the interaction of heat influenced zones is,thus causing the enhancement of stress concentration in the vicinity of welding-spot,and appearance of micro-cracks and the decrease of fatigue life.With increase of the distance between welding-spots,the interaction of heat influenced zones rapidly decreases,and its strength and rigidity affected by the strengthening effects of welding-spot decrease correspondingly.