Crack opening displacement and the rate of fatigue crack growth

1972 ◽  
Vol 8 (2) ◽  
Author(s):  
R.J. Donahue ◽  
H.McI. Clark ◽  
P. Atanmo ◽  
R. Kumble ◽  
A.J. McEvily
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Opening Displacement ◽  
Crack Opening ◽  
Opening Displacement

Effect of Interface Damage on Fatigue Crack Growth for SiC Fiber-Reinforced Ti-15-3 Matrix Composite

2000 ◽  
Author(s):  
Yoshihisa Tanaka ◽  
Yu-Fu Liu ◽  
Chitoshi Masuda
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Length ◽  
Crack Growth ◽  
Crack Opening Displacement ◽  
Test Temperature ◽  
Wear Behavior ◽  
Crack Opening ◽  
Opening Displacement ◽  
Crack Wake

Abstract The fatigue crack growth behavior in SiC (SCS-6) fiber reinforced Ti-15-3 matrix alloy composite subjected to a constant tension-tension loading mode was studied using single edge specimen in 2 × 10−3 Pa vacuum at 293 and 823K, with a frequency of 2 Hz, and a stress ratio of R = 0.1. Direct measurement of the fatigue crack length, and the crack opening displacement along the crack wake during the test were carried out by scanning electron microscope (SEM). The increase in the test temperature was found to lead to a decrease in the fatigue crack growth rate. The degradation of bridging fibers in the crack wake was severe for T = 293K, and this behavior was dependent of the test temperature. Fine particle-like debris was found on the fracture surface in the region of crack propagation in specimens tested at T = 823K. This is thought to be caused by the interface wear behavior. The crack opening displacement along the crack wake tested at T = 823K decreased with increasing crack length, and this tendency is dependent on the applied stress range. The associated increase in the crack tip shielding is explained on the basis of the crack closure due to the matrix relaxation by fatigue creep and the interface wear behavior.

Crack opening displacement and the rate of fatigue crack growth

1972 ◽  
Vol 8 (2) ◽  
pp. 209-219 ◽  
Author(s):  
R. J. Donahue ◽  
H. McI Clark ◽  
P. Atanmo ◽  
R. Kumble ◽  
A. J. McEvily
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Opening Displacement ◽  
Crack Opening ◽  
Opening Displacement

Numerical analysis of fatigue crack growth using a plastically dissipated energy factor based model

2021 ◽  
pp. 095440622110478
Author(s):  
Jie Wang ◽  
Wei Jiang
Keyword(s):  
Numerical Simulation ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Opening ◽  
Dissipated Energy ◽  
Plastic Behavior ◽  
Opening Displacement ◽  
Load Range ◽  
Simulation Scheme

The investigation of fatigue crack growth (FCG) behavior may contribute to the assessment of damage tolerance of components. To study the FCG behavior considering the elastic–plastic behavior at the crack tip, a numerical simulation scheme based on compact tension (CT) specimen is developed. Also, an effective plastically dissipated energy (PDE) factor composed of maximum PDE ([Formula: see text]) and PDE range ([Formula: see text]) is proposed to establish the expression for evaluating the FCG rate. The simulation results show good agreement with the results of test under same load conditions. Also, the mesh sensitivity analysis and the comparison with test results confirm the validation of proposed model. Based on the proposed numerical simulation scheme, the FCG behavior is studied by analyzing the influence of plastic wake, mean load, load range, overload, underload, load sequence, and cyclic compression load on FCG from the perspective of crack driving force, FCG rate, and crack opening displacement (COD). It is found from the analysis results that the developed numerical simulation scheme can consider the load history effect and crack closure effect. The mechanisms of these factors on the influence of FCG rate are analyzed in detail.

Effects of a Single Overload on Fatigue Crack Growth of Type 316 Stainless Steel

2021 ◽  
Author(s):  
Koji Miyoshi ◽  
Masayuki Kamaya
Keyword(s):  
Growth Rate ◽  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Opening ◽  
Constant Amplitude ◽  
Single Overload ◽  
Tensile Overload

Abstract The effect of a single overload on the fatigue crack growth rate was investigated for Type 316 stainless steel. Fatigue crack growth tests were conducted by controlling strain and load. Tensile and compressive overloads were applied during constant amplitude cycling. The overload ratio, which was defined as the ratio of overload size to baseline constant amplitude, was also changed. The constant amplitude tests were conducted at the strain or the stress ratio of −1.0 which was defined as the ratio of the minimum value to the maximum value. The crack opening point was obtained by the unloading elastic compliance method. The crack growth rate increased after the single compressive overload. The accelerating rate increased with the overload ratio. In contrast, not only the acceleration but also the retardation of the crack growth rate was observed for some tensile overload cases. The crack growth rate increased for relatively small tensile overload cases and decreased for relatively large tensile overload cases. The change in the crack opening level was examined. The crack growth rates after tensile and compressive single overloads correlated with the effective strain and stress intensity factor ranges both for load and strain controlling modes.

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