In this paper we derive conditions on the internal wear process under which the resulting time-to-failure model will be of the simple collapsible form (Oakes, 1995, Duchesne and Lawless, 2000) when the usage accumulation history is available. We suppose that failure occurs when internal wear crosses a certain threshold and/or a traumatic event causes the item to fail (Cox, 1999 and Bagdonavičiu...

In this paper we derive conditions on the internal wear process under which the resulting time-to-failure model will be of the simple collapsible form (Oakes, 1995, Duchesne and Lawless, 2000) when the usage accumulation history is available. We suppose that failure occurs when internal wear crosses a certain threshold and/or a traumatic event causes the item to fail (Cox, 1999 and Bagdonavičiu...

Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of...

The analysis of new and used oil for concentration trends of wear metals and for formulation or depletion of additive package metals has been around for over 30 years. Wear metals such as copper (Cu) and iron (Fe) may indicate wear in an engine or any oil-wetted compartment. Boron (B), silicon (Si) or sodium (Na) may indicate contamination from dirt or antifreeze leading to a failure. Additive ...

Ultra-high-molecular weight polyethylene (UHMWPE) wear, debris-induced osteolysis is a frequent cause of failure of total hip arthroplasty. Metal-on-metal total hip arthroplasty eliminates the generation of UHMWPE particulate debris. Although the volumetric wear of a metal-on-metal articulation may be lower than a metal-UHMWPE articulation, the number of particles may be higher. Osteolysis can ...

Abstract In general, Physical Vapor Deposition (PVD)-TiN coated High Speed Steel (HSS) endmills used to machine carbon steels can perform better at high cutting speeds compared with uncoated tools resulting in better surface finish and longer tool life. Flank wear is believed to be the main wear type that leads to shorten the life of these cutting tools. In this study, the roles of the coating ...

Many designs of unicompartmental knee replacement show early and mid-term failure due to polyethylene wear. We studied the wear rate of congruent polyethylene meniscal bearings retrieved from failed Oxford unicompartmental knee replacements. We examined 16 bearings, 0.8 to 12.8 years after implantation, measuring their thickness and comparing it with that of 14 unused bearings. The mean rate of...

Cross-linked polyethylene has been explored as an alternative to conventional polyethylene in total joint replacement in order to reduce wear volume and decrease failure through polyethylene wear debris induced osteolysis [1]. Due to the demands of a total knee replacement, moderately cross-linked polyethylene is recommended to retain mechanical properties [2]. This study aims to investigate th...