FATIGUE FRACTURE-BEHAVIOR OF PEEK

Experimental results on fatigue crack propagation in PEEK under different load levels, specimen thickness, and environmental temperatures reported in References [1] and [2] are analyzed. When the kinetic data is plotted against J1 = sigma(y)delta (where sigma(y) is the yield stress of the material and delta is the crack tip opening displacement), the crack speed is practically independent of the load level, specimen thickness, and environmental temperatures up to 75-degrees-C. The experimental data is confronted with a power type kinetic equation and the kinetic equation of the crack layer model. The analysis indicates that both kinetic equations describe well the data under a wide spectrum of loading conditions.