Analysis evaluation study on the fatigue crack propagation behavior of the structures with one-sided welding of the fillet welded joint for load carrying type.

Abstract

Hydraulic excavators and cranes are major heavy equipment with numerous one-sided welded joints. Although fillet welded joints are easily implemented and economical, the unwelded portion frequently initiates crack propagation. Because of this problem, high evaluation method is needed for the unwelded area. In this study, the fatigue properties and the fracture mechanism of the load carrying type fillet joints with one-sided welding were investigated experimentally to evaluate its fatigue damage with high accuracy based on the experimental and FEM analysis results. As the results, we confirm multiple initial cracks occur in 5% of lifetime. And we modeled initial crack of FEM according as 3-dimentional observation of fatigue crack propagation and we improve analysis accuracy.