Wear rates volumetric

G Layering rate cmVs inVs V Volumetric wear rate cmVs inVs... 

Each mechanism of breakage implies a different functional dependence of breakage rate on material properties. For the case of abrasive wear of ceramics due to surface scratching by loaded indentors, Evans Wilshaw [Acta Metallurgica, 24, 939 (1976)] determined a volumetric wear rate V of... 

By considering wear to occur by the intersection of subsurface lateral cracks which depend on the load and material properties, Evans and Wilshaw (1976) determined the volumetric wear rate, Vwean to be... 

Hence for a fixed load the volumetric wear rate dV/dL is constant. A physical model of wear has been derived from the purely geometric... 

Load is one of the basic physical quantities governing wear in engineering practice and thus, explicitly or implicitly, it is a parameter in any wear model. For instance, Eqns 13-30 and 13-37 are explicitly linear with respect to load and therefore plots of volumetric wear rate against load in log-log coordinates should have a slope of unity. Ar-... 

Perhaps more relevant from a clinical perspective, UHMWPE is significantly more abrasion resistant and wear resistant than HDPE. The following wear data for UHMWPE and HDPE was collected using a contemporary, multidirectional hip simulator (Edidin and Kurtz 2000). Based on hip simulator data, shown in Figure 1.5, the volumetric wear rate for HDPE is 4.3 times greater than that of UHMWPE. 

Chamley also suggested that the volumetric wear rate, as opposed to the LWR, may also be a clinically relevant metric for wear, as the biological stimulus may be related to the volume of wear debris (Chamley, Kamangar, and Longfield 1969). If the femoral head penetrates the cup following a linear trajectory (an assumption that was verified by Chamley s clinical experience with PTFE), the wear volume will be approximated as a cylinder having the projected circular area (A) of the femoral head and a height equal to the dep of penetration. Under this assumption, the volumetric wear rate (VWR) can be calculated as follows ... 

Volumetric Wear Rate (mm /year) Based on Radiographs for the Modular HG I Acetabular Component as a Function of Implantation Time... 

Oparaugo PC, Qarke IC, Malchau H, Herberts P. Correlation of wear debris-induced osteolysis and revision with volumetric wear-rates of polyethylene a survey of 8 reports in the literature. Acta Orthop Scand 2001 72(l) 22-8. 

Determining the volumetric concentration of wear particles in each size range for each material or device and then integrating these values with the biological activity function for UHMWPE allows the SBA for each material or device tested to be determined. The SBA can then be integrated with the volumetric wear rate (in mmVmillion cycles) to give a measure of functional biological activity (FBA),... 

Mean volumetric wear rates ( 95% confidence Umits) 1020 and GUR 1050 UHMWPEs in the hip and the knee. 

Bearing Couples Volumetric wear rate (mn eor) Linear wear rate (tan/year)... 

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