L. Pruitt et al., CYCLIC COMPRESSIVE LOADING RESULTS IN FATIGUE CRACKS IN ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE, Journal of orthopaedic research, 13(1), 1995, pp. 143-146
Wear damage to the articulating surfaces of total joint components mad
e of ultra high molecular weight polyethylene is associated with a fat
igue fracture mechanism, despite the fact that these surfaces are subj
ected to primarily compressive and compressive-tensile cyclic stresses
. The question arises as to whether fatigue cracks will form under suc
h loading conditions. In this study, we experimentally demonstrated th
at fatigue cracks could be initiated and propagated in notched ultra h
igh molecular weight polyethylene specimens subjected to fully compres
sive and compressive-tensile cyclic loading. Under these loading condi
tions, growth of fatigue cracks was limited: the cracks arrested witho
ut catastrophic failure of the test specimens. The final length of the
crack was dependent on the load ratio of the fatigue cycle; fatigue c
racks propagated to greater lengths as the load ratio was increased.