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Elastic-plastic response is greatly involved in the failure of wire ropes. Based on the derivation of the local deformation parameters of individual wire, an analytical model characterizing the elastic-plastic behavior for both wire strands and multi-strand ropes is developed in this paper. Also, the contact status within a multilayered strand is carefully studied to achieve a full understanding of wire stresses. Details of the surface strain fields of ropes are captured by 3D digital image correlation (3D-DIC) technique and the results agree well with the prediction of the present model. Varying loading conditions are considered to analyze the yielding and failure behavior of wire strands. It is found that the rotation of ropes (no matter its positive or negative) will increase the overall stress level over the wire cross section, however, restraining the rope ends leads to higher contact stress. Increasing the helix angle moderately may be an effective method to reduce the contact pressure of strand wires. Our model provides straightforward prediction of the elastic-plastic response of wire ropes and proves an effective tool for rope design due to a great reduction of time consuming in numerical simulations. [ABSTRACT FROM AUTHOR]

A new model characterizing the response of a multi-strand wire rope subjected to axial tension and axial torque is presented in this paper. Apart from most of previous approaches which deal with a straight wire strand, the present model fully considers the double-helix structure in multi-strand configuration. To be further, a new method to compute local deformation parameters (two curvatures and a twist defined by Love, 1944) of each wire is introduced. The proposed model well predicts the global stiffness of the rope. It is found that different friction states between adjacent wires can lead to quite a different distribution of local bending and torsion deformation of double-helix wire. The variations of stresses in double-helix wires along the rope axis are analyzed and the results show that torsion stress of a double-helix wire can be neglected when the rope is subjected to axial tension (axial torsion is restrained). The present model provides a new way to estimate the local deformation and stresses at the wire level, which sheds new insight into the understanding of the fatigue and failure behavior of the wire rope. [ABSTRACT FROM AUTHOR]

Abstract: The elastic solutions for a mixed dislocation in a general multilayer with N dissimilar anisotropic layers are obtained via a generalized image decomposition method. The original problem is decomposed into N homogeneous subproblems with strategically placed continuously distributed image (virtual) dislocations which satisfy the consistency conditions for degenerate N − M (M < N) layer problems. The image dislocations are used to satisfy the interface or free surface conditions, and represent the unknowns of the problem. The resulting singular Cauchy integral equations are transformed into non-singular Fredholm integral equations of the second kind using certain H- and I-integral transforms. The Fredholm integral equations are then solved via the classical Nyström method. The general decomposition and the elimination of all singular integrals yield an exact formulation of the problem; the approximation arises only in the Nyström method. The dislocation mixity and the number of layers dissimilar in thickness and elastic anisotropy can be handled without difficulty, constrained only by the number of linear algebraic equations in the Nyström method for large N. For the numerical study, image forces on a dislocation in two- and three-layer systems are calculated. The accuracy of the results is verified by checking the boundary conditions and by comparison with previous results. The dependence of the image force on the dislocation position and mixity, and on the layer thicknesses and elastic anisotropies, is also illustrated via numerical investigations. [Copyright &y& Elsevier]