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An Experimental Investigation of Limit Loads and Fatigue Properties of Spot Welded Specimens

점용접시편의 극한하중과 피로특성에 관한 실험적 고찰

Lee, Hyeong-Il;Kim, Nam-Ho;Lee, Tae-Su
이형일;김남호;이태수

  • Published : 2000.01.01

Abstract

The study on the mechanical behavior of a spot-welded specimen is largely divided into the quasi-static overload failure analysis and the fatigue failure prediction. The main issue in an overload analysis is to examine the critical loads, thereby providing a generalized overload failure criterion. As the welding spot forms a singular geometry of an external crack type, fatigue failure of spot-welded specimens can be evaluated by means of a fracture parameter. In this study, we first present the limit loads of 4 representative types of single spot-welded specimens in terms of the base metal yield strength and specimen geometries. Recasting the load vs. fatigue life relationships experimentally, obtained here, we then predict the fatigue life of spot-weld specimens with a single parameter denoted the equivalent stress intensity factor. This crack driving parameter is demonstrated to successfully describe the effects of specimen geometry and loading type in a comprehensive manner. The suggested fatigue life formula for a single spot weld can play a key, role in the design and assessment of spot-welded panel structures, in that the fatigue strength of multi-spots is eventually determined by the fatigue strength of each single spot.

Keywords

Spot Welding;Overload Failure;Limit Load;Fatigue Failure;Fatigue Life;Fracture Mechanics;Equivalent Stress Intensity Factors

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