Stress/Strain Induced Void?

Abstract

Fracture micro mechanisms of ductile porous solids are substantially researched worldwide since last 60 years through different experiments, theories, thermodynamics and computer models. It is still attracting immense interests to the scientists/engineers as evidenced by a slew of many interesting and innovative techniques, different perceptions and philosophies to elucidate ductile fracture micro mechanisms of materials. The damage accumulation (i.e., void volume fraction, fv) inside a ductile material under tensile deformation is strongly dependent on many engineering/metallurgical variables with their complex and unknown interactions. The role of micro void nucleation and growth during ductile fracture of materials under different environments and loading conditions is well established and documented, but the details of some micro mechanisms governing this fracture process are not still clearly understood. Such as, the coalescence of micro voids has not been clarified clearly, since it is an unstable and rapidly occurred phenomenon in materials. A comprehensive and exhaustive literature review has been performed to realize these facts completely. This article also critically reviews the standard computational methods often widely used for fracture mechanics analysis, which have been proposed/developed by eminent scientists to simulate the ductile fracture of materials. Many studies monitoring the damage accumulation during tensile deformation of different ductile alloys which are, in principle, affected by the imposed stress triaxiality, applied stress and the resulting plastic strains, are already available in the open published literatures. But it is still not clear in these circumstances, whether this damage accumulation is stress assisted or strain induced. In the current investigation, it has been demonstrated through experiments, modeling and reviewing from existing literature that damage accumulation inside a material can be effectively explained by imposed stress triaxiality. This article would be truly being a gift to the structural materials and solid mechanics communities as a whole.