Analysis of Fatigue Crack Propagation Behavior of Structures with One-Sided Welding in Fillet Welded Joint for Load-Carrying Type

Abstract

The structures of a hydraulic excavator with one-sided welded joints are investigated in this study. We investigated the fatigue lifetime evaluation method using S-version FEM. Especially we considered combination of cracks from multiple crack origins. Moreover, to achieve a more precise evaluation, we obtained the crack growth rate of the excavator weld using the unloading elastic compliance method instead of some engineering standard values. Results show that, the fatigue lifetime obtained from the analysis of all width crack; type1 - all cracks named in this study is extremely short compared with test results. Considering the combination of cracks from multiple crack origins, the S-version FEM provides an evaluation similar fatigue lifetime of a test piece imitating the excavator.

Fatigue lifetime estimation using the S-version FEM (The number of cracks comparison).