용접잔류응력이 자동차 카울 구조에 미치는 영향

Abstract

The lightweight in automotive industry is important due to the demand of CO2 emission reduction and fuel efficiency. Many automotive parts are mostly made by Resistance Spot Welding. Laser Beam Welding has potential to substitute the Resistance Spot Welding in terms of automotive lightweight.

This study aim is to evaluate the structural stability of automotive cowl by numerical analysis. In this study, three steps analysis for heat conduction, thermal elastic-plastic and structural analysis considering welding residual stress were conducted.

In short, the analysis result shows that in comparison with residual stress of single pass and multi pass welding, the welding residual stress in Resistance Spot Welding become higher than that of Laser Stitch Welding about 10 percent.

On applying the external force to Resistance Spot and Laser Stitch weld joints, stress distribution show that tensile residual stress increased in the Base Metal and compressive residual stress increased in the Heat Affected Zone.