Effect of Specimen Size on Fatigue crack Growth Rate in Steels

J. Ocean Eng. Technol. 2000;14(2):99-105.

강재의 피로균열전파율에 미치는 시험편 크기의 영향

안석화

부경대학교 기계공학부

Keywords: fatigue crack growth rate, Specimen thickness, Stress ratio, Specimen width, Aspect ratio, Constant stress intensity factor range controlled test

핵심용어: 피로균열전파율, 시험편 두께, 응력비, 시험편 폭, 균열형상비, 응력확대계수일정제어시험

Abstract

This paper describes the effect of specimen size on fatigue crack growth rate for the offshore structural high-tensile-strength steel BS4360 and machine structural steel SM45C. The purpose of the present study is to investigate the effect of stress ratio aspect ratio specimen width and specimen thickness of the fatigue crack growth behavior. Compact tension specimens with a LT orientation for BS4360 and SM45C steels were used, All testing was done at constant stress intensity factor range controlled fatigue crack growth condition. The investigation demonstrates that the fatigue crack growth rate is increased with increasing stress ratio and specimen thickness and is decreased with increasing specimen width. The fatigue crack growth rate is unaffected by aspect ratio until a/W=0.50 but is increased by increasing spect ratio from a/W=0.55