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Non-uniform rational B-splines (NURBS) are a convenient way to integrate CAD software and analysis codes, saving time from the operator and allowing efficient solution schemes that can be employed in the analysis of complex mechanical problems. In this paper, the Isogeometric Boundary Element Method coupled with Bézier extraction of NURBS and conventional BEM are used for analysis of 2D contact problems under cyclic loads. A node-pair approach is used for the analysis of the slip/stick state. Furthermore, the extent of the contact area is continuously updated to account for the nonlinear geometrical behaviour of the problem. The Newton–Raphson's method is used for solving the non-linear system. A comparison to analytical results is presented to assess the performance and efficiency of the proposed formulation. Both BEM and IGABEM show good agreement with the exact solution when it is available. On most examples, they are equivalent with some advantage for IGABEM, though the former is slightly more accurate in some situations. This is probably due to the smoothness of NURBS not being able to describe sharp edges on tractions. As expected, IGABEM incurs in higher computational cost due to the basis being more complex than conventional Lagrangian polynomials. [ABSTRACT FROM AUTHOR]

The problem of complete frictional contact between a square elastic block and an elastically similar half-plane is considered when the block is first pressed normally into the half-plane and then a monotonically increasing shear force is applied until sliding is achieved. Numerical results show that for moderate levels of shear force (i.e. less than 50% of the sliding condition) very different qualitative behaviour is observed for high and low coefficients of friction. However, for high shear forces (i.e. near to the sliding condition), the response for high and low friction coefficients is similar. [ABSTRACT FROM AUTHOR]

Abstract: Plastic deformation at the scale of microstructure plays an important role in fretting fatigue failure of metals under cyclic loading. In this study, crystal viscoplasticity theory with a planar triple slip idealization is employed to represent crystallographic plasticity in two-dimensional fretting analyses of Ti–6Al–4V. Subsurface deformation maps, fretting maps, and shakedown maps are constructed based on application of J 2 plasticity theory for the polycrystalline substrate. Comparisons are then made with polycrystal viscoplasticity simulations, the latter suggesting that plastic ratchetting plays a significant role in the fretting fatigue process. [Copyright &y& Elsevier]