Prediction of Welding Distortion in a Part of Motorcycle Using Inherent Deformations Obtained from Inverse Analysis for Aluminum Alloy Welded Joints

Thursday, June 5, 2008 - 9:45 AM

Prediction of Welding Distortion in a Part of Motorcycle Using Inherent Deformations Obtained from Inverse Analysis for Aluminum Alloy Welded Joints

H. Serizawa, T. Yamamoto, H. Murakawa, Osaka University, Osaka, Japan; T. Mizuno, M. Enyama, Suzuki Motor Corporation, Shizuoka, Japan; F. Matsuda, Suzuki Motor Corporation, Kanagawa, Japan

In the fabrication processes of transportation equipments, there is a strong demand to control the welding distortion of aluminum alloy joints, which has been widely used in order to reduce the weight of products. As one of the most effective tools to predict the welding distortion, an elastic finite element analysis using the concept of inherent deformation has been employed, where the inherent deformations for various types of welded joints have to be known as the database. So, in this research, the inherent deformations of the simple aluminum alloy joints, which are butt welded joint and lap joint of plates, were estimated through the inverse analysis.

In order to examine the effects of variation in the real fabrication process on the inherent deformation, the welding pass and the gap between the plates were varied. As for the inherent deformation, four fundamental deformations, which are longitudinal shrinkage, transverse shrinkage and angular distortions in two directions, were taken into account in the inverse analysis.

In all the deformations obtained, the longitudinal shrinkage was largest and increased with increasing the welding pass. The longitudinal shrinkage in the butt joints with 0.5 and 1.0 mm gap was larger than that of the no-gap joint, while there was no influence of the gap on the longitudinal shrinkage in the lap joint. Since the longitudinal shrinkage in the butt joint with 0.5 mm gap was almost the same as that with 1.0 mm gap, it was found that the existence of gap was important regardless of the gap length. Also, in order to examine the applicability of the inherent deformations obtained, the welding distortion of a tank rail in the practical motorcycle was predicted using these deformations and it was revealed that the computed distortion had a fairly good agreement with the experimental result.

Summary: The inherent deformations of the simple aluminum alloy welded joints were obtained from the inverse analysis. Also, the welding distortion of a part of the practical motorcycle was predicted using those inherent deformations and compared with the experimental result.