Crack-Growth Analysis Results and Discussion Concluding Remarks 236 237 240 243 247 247 251 252 255 259 263 LIFE PREDICTION AND APPLICATIONS Prediction of Fatigue Crack Growth Under Irregular LoadinguD. V. NELSON AND H. O. FUCHS Input Data for Predictions Crack Growth FATIGUE CRACK GROWTH PREDICTION OF FIBRE Keywords:Fatigue crack growth, Fibre metal laminates, variable amplitude loading,crack retardation, GLARE Abstract A recently developed analytical prediction model for constant amplitude loading has been ex-tended to predict fatigue crack growth of Fibre Metal Laminates under variable amplitude load-ing. Accuracy of the model has been discussed in
rate in the initial and final stage of fatigue, i.e., in the crack nucleation and final fracture zone respectively. NASGRO software also considered the effect of crack closure while calculating the fatigue life. In this research, only the life of the fatigue crack propagation stage was calculated, and the values of p and q were assumed as 0. Fatigue Crack Growth under Variable-Amplitude Loading Padmadinata, U.H. and Schijve, J., Prediction of fatigue crack growth under flight-simulation loading with the modified CORPUS model. Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance (Harris, C.E., Ed.). NASA Conf. Publ. 3274, (1994) pp.547562. Google Scholar Fatigue crack growth and life prediction under mixed Fatigue crack growth life as a function of crack length is essential for the prevention of catastrophic failures from damage tolerance perspective. In damage tolerance design approach, principles of fracture mechanics are usually applied to predict the fatigue life of structural components. Numerical prediction of crack growth versus number of cycles is essential in damage tolerance design.
Zhenyu Ding, Xiaogui Wang, Zengliang Gao, Shiyi Bao, An experimental investigation and prediction of fatigue crack growth under overload/underload in Q345R steel, International Journal of Fatigue, 10.1016/j.ijfatigue.2017.01.024, 98, (155-166), (2017). Fatigue crack growth under variable amplitude loading Part Zhenyu Ding, Xiaogui Wang, Zengliang Gao, Shiyi Bao, An experimental investigation and prediction of fatigue crack growth under overload/underload in Q345R steel, International Journal of Fatigue, 10.1016/j.ijfatigue.2017.01.024, 98, (155-166), (2017). LIFE PREDICTION BY SIMULATION OF CRACK GROWTH IN life prediction by simulation of crack growth in notched components with different microstructures and under multiaxial fatigue T Hoshide Department of Energy Conversion Science, Faculty of Energy Science, Kyoto University, Sakyoku, Kyoto 60601, Japan
This work concentrates on the fracture behaviour of the compact tension specimen under mixed-mode loading, and numerical investigation using ANSYS Mechanical APDL 19.2 finite element program with different modes of mix angles is carried out. The prediction of mixed-mode fatigue life under constant amplitude fatigue loading for the compact tension shear specimen (CTS) is employed using Paris On the theoretical modeling of fatigue crack growth3 The arguments described here pertain tofatigue-crack growth in mode I, i.e., along a path nominally perpendicular the maximum tensile stresses (where K II = 0). The vast majority of experimental and theoretical studies on fatigue-crack growth have been carried out for this situation as this is invari- ably how fatigue cracks propagate in service. Prediction Methods for Fatigue Crack Growth in Aircraft In the second part recent work on prediction problems is reported. This includes ( a ) crack growth under flight-simulation loading with crack closure measurements, ( b ) predictions for flight-simulation loading based on a constant crack opening stress level, and ( c ) crack growth under pure random loading with different Srms -values, two
After crack length (a=15 mm), the specimens are growth under the same crack growth rate. Fig. 2 Fatigue crack growth curves in L-T orientation Fig. 3 Fatigue crack growth curves in T-L orientation B. Crack orientation effect The analysis and the comparison of Figs. 2 and 3 show the effect OF CRACK orientation on the fatigue crack growth life SIMULATION OF DELAMINATION GROWTH UNDER fatigue crack growth. In region II, where crack growth rates follow the Paris Law, a good agreement between the predictions and the experimental data is obtained. In region I there is negligible crack growth rate for small values of the normalized energy release rate and the numerical data follows the trend of the experimental data. A difference SIMULATION OF DELAMINATION GROWTH UNDER fatigue crack growth. In region II, where crack growth rates follow the Paris Law, a good agreement between the predictions and the experimental data is obtained. In region I there is negligible crack growth rate for small values of the normalized energy release rate and the numerical data follows the trend of the experimental data. A difference
The Paris law crack growth relationship given in Eq.1 was integrated to predict the growth of known initial cracks, as follows:(4) where N is the number of cycles needed to grow a flaw of initial size a i to a final size a f under stress range . Fatigue Crack Growth MechaniCalc