Fatigue crack propagation of ultra-high molecular weight polyethylene

Ultra high molecular weight polyethylene (UHMWPE) is an advanced polymer well-known for its outstanding physical and mechanical properties. The material is highly resistant to corrosion and abrasion. It has high impact strength and low coefficient of friction, naming it a suitable material for bearing applications. The material also has a high strength-to-weight ratio. In this study, the fatigue crack behavior of UHMWPE PE1000 and TIVAR H.O.T are of interest. The objective of this study is to determine the effect of load ratio R on the fatigue crack growth rate. The load ratio R was varied between 0.1, 0.3, and 0.5. Compact-tension specimens were used to perform experiments. The specimens were tested at room temperature with loading frequency of 10 Hz. Advancing crack growths were measured using a traveling microscope. The crack growth rates da/dN as a function of stress intensity factor deltaK were plotted in a log-log scale for each testing condition. For the two material, increasing load ratio R led to an increase in fatigue crack propagation resistance, as determined by the decrease in fatigue crack growth rate for a given deltaK value. When the two materials are in comparison, TIVAR H.O.T shows superior fatigue crack resistance. For a given deltaK value, PE1000 virgin displays higher fatigue crack growth rates than TIVAR H.O.T.