EXPERIMENTAL AND ANALYTICAL ESTIMATES OF FATIGUE CRACK CLOSURE IN AN ALUMINIUM-COPPER ALLOY PART II: A FINITE ELEMENT ANALYSIS

Abstract— A numerical investigation of the fatigue crack closure phenomenon has been performed by an elastic-plastic finite element analysis. Computer software was developed to consider many aspects affecting plasticity-induced crack closure. Linear and power-law hardening models are considered in the finite element analysis. The paper presents results from the study carried out on compact tension (CT) coupons at various crack lengths corresponding to different loading conditions. Finally the results of the analysis are compared with the experimental estimates of fatigue crack closure levels obtained from laser interferometry, scanning-electron and transmission-electron fractography presented in Part I of this paper on identical specimens.     

CREEP-FATIGUE CRACK GROWTH BEHAVIOR IN 1Cr-1Mo-0.25V STEEL. PART II: CRACK GROWTH BEHAVIOR AND MODELS

Abstract— Creep-fatigue crack growth (CFCG) behavior of an ex-service 1Cr-1Mo-0.25V steel was investigated for hold times of 100 s, 15 min, and 8 h for a trapezoidal loading waveform at a temperature of 538°C. The correlation of the crack growth rate with ( C _t)_avg for various hold times was significantly improved when an appropriate estimation scheme, previously proposed by the authors, was used to estimate this creep fracture mechanics parameter for this material. Crack growth data under creep-fatigue conditions and analysis procedures used to reduce them are described in detail in this paper.