铝胶焊双搭接接头上应力分布的数值分析

Numerical analysis on stress distribution in adhesive-welded double lap joint of aluminum

用弹塑性有限元法研究了胶粘剂弹性模量和焊点相对位置对铝胶焊双搭接接头胶层中应力分布的影响.结果表明,胶粘剂弹性模量对铝胶焊双搭接接头胶层中部和界面附近的应力分布的影响较为显著,采用低弹性模量胶粘剂使得焊点的承载作用突出;采用高弹性模量胶粘剂时,胶层所承担载荷增加.焊点中心位置对铝胶焊双搭接接头胶层中部的应力分布有一定影响,随焊点中心向搭接区左侧移动,铝胶焊双搭接接头胶层中部的应力峰值逐渐增大,等效应力由焊点中心与搭接区中心重合时的55.2MPa增大到焊点中心距搭接区中心7 mm时的77.4 MPa,增幅达40.2%.因此采用低弹性模量胶粘剂和使焊点中心与搭接区中心重合可以有效提高接头的承载能力.

The influence of the elastic modulus of adhesives and nuggets position on the stress distribution in adhesive-welded double lap joints of aluminum was investigated by elastic-plastic finite element method(FEM).The results obtained show that the influence of the elastic modulus of adhesive on the stress distribution in adhesive-welded double lap joints of aluminum is significant. The load subjected by the nuggets is greater when the elastic modulus of adhesive is lower and the load subjected by the adhesive layer increases when the elastic modulus of adhesive is higher.The effect of nuggets location is also significant when the center of the nugget is moved to the left end of the overlap zone. The peak stress along the mid-bonding line of the aluminum double lap joint increases when the center of the nuggets are moved to near the left end of the overlap zone.The peak value of the von mises equivalent stress increases from 55.2 MPa to 77.4 MPa when the nugget center is shifted from the point at 12.5 mm to 5.5 mm.Therefore,the load bearing ability of the adhesive-welded double lap joints of aluminum can be improved by lower elastic modulus adhesive and the center overlapping of the nugget and the lap zone.