일정진폭하중하의 피로균열전파의 통계적 특성

A Statistical Analysis of Fatigue Crack Growth under Constant-Amplitude Loads

  • Jeong, Hyeon-Cheol (Graduate School, Department of Mechanical Engineering, Pukyong National University) ;
  • Lim, Young-Kyu (Graduate School, Department of Mechanical Engineering, Pukyong National University) ;
  • Kim, Seon-Jin (School of Mechanical Engineering, Pukyong National University)
  • 발행 : 2002.05.17

초록

In this paper, a statistical analysis of fatigue crack growth behavior under constant amplitude loads has been carried out. Fatigue crack growth tests were conducted on sixteen pre-cracked compact tension (CT) specimens of the pressure vessel (SPV50) steel in controlled identical load and environmental conditions. The assessment of the statistical distribution of fatigue crack growth experimental data obtained from SPV50 steel was studied and also the correlation of the parameter C and m in the Paris-Erdogan law was discussed. The probability distribution function of fatigue crack growth life seems to follow the 3-parameter Weibull. The fatigue crack growth rate seems to follow the 3-parameter Weibull and the log-normal distribution. The coefficient of variation (COV) of fatigue crack growth life was observed to decrease as the crack grows. A strong negative linear correlation exists between the coefficient C and the exponent m in Paris model. Fatigue crack growth rate data shows a normal distribution for both m and logC.

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