Viggo Tvergaard

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Two distinct mechanisms of crack initiation and advance by void growth have been identified in the literature on the mechanics of ductile fracture. One is the interaction a single void with the crack tip characterizing initiation and the subsequent void by void advance of the tip. This mechanism is represented by the early model of Rice and Johnson and the(More)
Stress dependent electrochemical dissolution is identified as one of the key mechanisms governing surface degradation in fretting and crevice corrosion of biomedical implants. The present study focuses on delineating the roles of mechanical stress and chemical conditions on the life expectancy of modular hip implants. First, material removal on a stressed(More)
A preliminary theoretical study is carried out of the role of micron-scale patterning on the interface toughness of bonded Cu-to-Cu nanometer-scale films. The work is motivated by the experimental studies Mixed-mode interface toughness of wafer-level Cu–Cu bonds using asymmetric chevron test. J. Mech. Phys. Solids 56, 707–718.] wherein 400 nm Cu films were(More)
This extended comment is in response to a recent paper by Danas and Ponte Castañeda (2012) which investigates the stress– strain behavior and strain localization of porous metallic materials as a function of the Lode parameter under low triaxality stressing. The topic is of some importance owing to its relevance to recent experimental and theoretical work(More)
Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic-plastic model of a plate subject to shearing action by opposing rigid platens. Shear failure at the(More)
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