Article

Bearing Pressures and Cracks

Journal of Applied Mechanics 01/1939; 6:A49-A53.
6 Bookmarks
 · 
633 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The behavior of regular wavy surfaces in contact is important for the study of rough surface contact, and therefore has applications to the prediction of friction, wear, surface fatigue, and electrical and thermal contact resistance. This work characterizes the average surface separation between a sinusoidal surface and a flat rigid surface as a function of the average contact pressure or load using the finite element method (FEM). The FEM results also agree well with the limiting spherical based solutions at low contact pressures and the other asymptotic solution at high contact pressures. Empirical fits are provided that can approximately predict the average surface separation for both elastic and elastic–plastic sinusoidal contacts over a wide range of material properties. Contact stiffness can also be predicted from surface separation results.
    Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology. 08/2013; 227(12):1376-1385.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A new discrete element model (DEM) has been developed for the purpose of simulating dynamic fracturing driven by the internal generation of fluids in low permeability elastic solid bodies. The elastic material is represented by a network of nodes connected by springs, and fracture nucleation and propagation is implemented by splitting nodes and reconnecting the spring network. This produces realistic fracture shapes, and reduces lattice artefacts compared with DEM models in which fracturing is implemented by breaking/removal of springs. Fracture volumes and surfaces are explicitly represented in terms of the voids in the reconnected spring network, simplifying the coupling between mechanical deformation and fluid pressure in the fractures, and facilitating the modelling of fluid transport. The model is illustrated by applying it to fracturing driven by internal fluid generation in an impermeable quasi two-dimensional system. This is relevant for many geological processes, including primary migration of oil and gas in low-permeability source rock. The model may also be adapted to hydraulic fracturing processes, which are of industrial interest in connection with unconventional oil and gas production.
    Physica A: Statistical Mechanics and its Applications 12/2014; · 1.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, the contact of a rigid sinusoid sliding on a viscoelastic half-space is studied. The solution of the problem is obtained by following the path drawn by Hunter for cylindrical contacts. Results show that depending on the remote applied load, a transition from full contact conditions to partial contact may occur depending on the sliding velocity. This effect, which is not observed in smooth single asperity contacts, is related to the viscoelastic stiffening of the material and to the periodicity of the contacts. Frictional properties as well as contact area, displacement and pressure distributions are discussed in detail.
    Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences 07/2014; 470(2169):20140392. · 2.38 Impact Factor