Design of Excavator Boom Structure Based on Fatigue Strength of Weldment(Ⅱ)

Park, Sang-Chul

Journal of KWJS 2011;29(4):61-66.
Published online September 12, 2011.

용접부 피로강도를 고려한 굴삭기 붐 구조물 설계(Ⅱ)

Design of Excavator Boom Structure Based on Fatigue Strength of Weldment(Ⅱ)

Abstract

The purpose of this study is to develop improved boom structures with reliable fatigue strength of weldment and lower production cost. For that purpose, multi-body dynamic analysis was performed to evaluate forces acting on arm & boom cylinders and joints of boom structure during operation of an excavator for three working postures, then stress analysis was made to investigate stress distribution around diaphragms at the bottom plate of boom structures which was known to be susceptible to fatigue failures of welded joints, and finally boom structures with optimum arrangement of diaphragms was proposed. This work mainly consists of the following two parts: part 1 focuses on multi-body dynamic analysis of excavators during operation and part 2 includes evaluations of fatigue strength of welded joints for modified boom structures.

Key Words: Excavator, Bucket, Arm &, boom structures, Fatigue failures, Welded joint, Working posture, Diaphragm, equivalent stress, Loading block, Miner’s damage rule