title: Compressive stress relaxation behavior of irradiated ultra-high molecular weight polyethylene at 37 degrees C.
abstract: The preconditioned stress relaxation behavior of irradiated ultra-high molecular weight polyethylene (UHMWPE), a commonly used bearing surface in total joint replacements (TJR), was modelled in uniaxial compression at 37 degrees C. Twenty cylindrical specimens (10 mm dia. x 27 mm length) were machined from a compression molded plate of medical grade UHMWPE and gamma-irradiated to a minimum dose of 2.5 Mrad. At an initial strain rate 1000%/s, five specimens were each tested at constant strains of 1, 2, 5, and 10%. The modified superposition principle provided a good agreement of the nonlinear viscoelastic (stress relaxation) behavior of UHMWPE (standard error of 0.0753 MPa).
authors.affiliation: Clinical Mechanics Group, Queen's University, Kingston, Ontario, Canada.
authors.forename: S D
authors.initials: SD
authors.lastname: Waldman
authors.forename: J T
authors.initials: JT
authors.lastname: Bryant
mesh_terms: D001672:Biocompatible Materials; D004548:Elasticity; D006801:Humans; D007595:Joint Prosthesis; D008433:Mathematics; D008962:Models, Theoretical; D008970:Molecular Weight; D011095:Polyethylenes; D013314:Stress, Mechanical; D013704:Temporomandibular Joint; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes