Dr. Liyang XieProfessor, Northeastern University, China
Speech Title: On Fatigue Damage Definition and Failure Probability Prediction in Probabilistic Framework
Abstract: Fatigue damage is usually defined as ∑ni / Ni , i.e., the sum of the ratios of stress cycle number to fatigue life under different stress levels. When fatigue life needs to be treated as a random variable, such definition will result in complex cumulative damage calculation. Besides, different definition on fatigue damage implies different critical damage for fatigue failure criterion. This paper defines and discusses different fatigue damage definitions and corresponding issues about failure probability prediction under variable amplitude stress histories. It shows that in the situation of fatigue life following the three-parameter Weibull distribution, the fatigue damage defined based on the location parameter, i.e., the threshold of the random life, is appropriate for cumulative fatigue damage calculation and probabilistic fatigue life prediction.
Keywords: Fatigue damage, critical damage, fatigue life, Weibull distribution, failure probability.
Biography: Prof. Liyang Xie is a professor of Mechanical Engineering at Northeastern University, Shenyang, China. He received his BS (1982) in mechanical Manufacturing, MS (1985) & PhD (1988) in structural integrity from Northeastern University, Shenyang, China. He worked one year (1996) in the Probabilistic Safety Analysis Institute, TUVE Nord, Hamburg, Germany and two more years in the Department of Plant Safety, Otto-von-Guericke University, Magdeburg, Germany during 1997-1998. His research interests include structural integrity, reliability and system probabilistic risk analysis. He has published more than 100 research papers in peer reviewed journals and six books. He is editorial board member of Int. J. of Reliability and Safety, Int. J. of Advances in Reliability and Engineering Failure Analysis. He is Vice Chairman of Fatigue Branch of Chinese Materials Research Society, Vice Chairman of Reliability branch of Chinese society of Mechanical Engineering.