A Study on the Stress Concentration Factor and Fatigue Strength for T-Tubular Joints by FEM

J. Ocean Eng. Technol. 1994;8(2):141-150.

유한요소법에 의한 튜블라 이음부의 응력집중계수 및 피로강도 해석

엄동석,강성원,하우일

부산대학교 공과대학,대우중공업㈜선박해양연구소,현대중공업㈜선박해양연구소

Keywords: Tubular joint, Stress concentration factor, Fatigue crack initiation life, e-N curve, Chord, Brace, Axial load

핵심용어: 튜블라 이음부, 응력집중계수, 피로균열발생수명, e-N 선도, 코드, 브레이스, 축하중

Abstract

In designing, the strength of tubular joint has been an important problem for integrity of steel structures in which many tubular members are used. This paper presents the results of FEM analysis on stress concentration and fatigue crack initiation life for two types of tubular joints. One is circular and rectangular T type joints which consist of circular brace and rectangular chord. Another is circular and circular T type joints which consist of circular brace and circular chord. FEM analyses were performed under the axial load and in-plane bending moment. The fatigue crack initiation life can be estimated by using $varepsilon$-N curve and by applying the Palmgren-Miner linear damage rule. According to the results, the stress concentration factor(SCF) of circular and rectangular joints is higher than that of circular and circular joints. The fatigue crack initiation lives of circular-circular joints and circular-rectangular joints were calculated.