FINITE ELEMENT ANALYSIS OF MECHANICAL BEHAVIOR OF MECHANICAL COMPONENTS UNDER COMPRESSION

Abstract

First, finite element analysis is used to numerically investigate the influence of superimposed hydrostatic pressure on ductility and fracture strain of compressed rings, using the ABAQUS/Explicit solver. As hydrostatic pressure increases, the stress state at the cross-section of the ring changes, and the tensile radial and tangential stress components become compressive. Decreasing stress triaxiality results in higher values of fracture strain. Radial stresses at the ring’s cross-section are more easily affected by hydrostatic pressure. The numerical results show that strain to fracture increases linearly with the hydrostatic pressure regardless of the shape factor or geometry of the rings. Second, the effects of strain rate sensitivity on fracture of laminated rings under dynamic compressive loading are numerically investigated. Adding layers of rate-sensitive material at the outer wall enhances the ductility of the rings. The topographic arrangement and layer thickness play an important role in the crack initiation and propagation path. In the case of having layers of brittle materials inside the cross-section, the cracks initiate in the brittle layers first, from the inner layers at the cross-sections. When the layer thickness is relatively high, a delamination-like behavior occurs at the interface of hard and soft materials. Third, responses of cubic shear–compression models are analyzed numerically. A set of approximate analytical relations are determined to obtain effective stress and effective strain of the material from the displacements of the gauge section and reaction force. A universal prediction model is determined, based on the analyses of 125 simulations, and its performance is tested. The predicted stress–strain curves are in good agreement with the input stress–strain curves of the material with an average error of approximately 3%. These numerical results set a basis for determining stress–strain curve of materials directly from the force–displacement curves of shear–compression tests.