Hydrostatic stress

About: Hydrostatic stress is a research topic. Over the lifetime, 1568 publications have been published within this topic receiving 37773 citations.

Rock strength criterion considering the effect of hydrostatic stress on lode angle effect

Abstract: 1State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, China 2State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, China 3Deep Earth Energy Research Laboratory, Department of Civil Engineering, Monash University, Melbourne, Victoria, Australia 4Department of Civil and Mineral Engineering, University of Toronto, Toronto, Ontario, Canada

A Constitutive Model for Porous Shape Memory Alloys Considering the Effect of Hydrostatic Stress

Abstract: A constitutive model considering the effect hydrostatic stresses induced by porosity on the macroscopic behavior of porous Shape Memory Alloys (SMAs) is developed in this paper. First, a unit-cell model is adopted to establish the constitutive relations for the porous SMAs with SMA matrix and the porosity taken to be voids. Dilatational plasticity theory is then generalized for the SMA matrix. Based on an approximation of the velocity field and the upper bound theory, an explicit yield function for the porous SMA is derived from micromechanical considerations. Finally, an example for the uniaxial response under compression of a porous Ni-Ti SMA material under isothermal condition is supplied by using the dense Ni-Ti SMA parameters. Good agreement between the theoretical predictions of the proposed model and published experimental data is observed, and the model can be available to different porosities.

Simulation of hydride-induced steady-state crack growth in metals – Part II: general near tip field

Abstract: Hydride-induced steady-state crack propagation in metals is investigated under conditions of constant temperature, plane strain, small-scale yielding and small-scale hydride precipitation, by taking into account the coupling of the operating physical processes It is shown that the near-tip field depends on a normalized stress intensity factor, which incorporates both effects of the applied stress intensity factor and the crack velocity According to Part I of the present study, when the normalized stress intensity factor tends to zero, the crack-tip field near the threshold stress intensity factor is produced, which is characterized by a constant hydrostatic stress in the hydride precipitation zone As the value of the normalized stress intensity factor increases, the evolution of the near-tip field for crack propagation from stage-I to stage-II regime is produced: the actual size of the hydride precipitation zone decreases, the hydrostatic stress increases, deviating from the level of the plateau, and the near-tip field tends to that of a hydrogen-free metal The near-tip field depends strongly on hydrogen concentration, far from the crack tip The stage-II crack growth velocity is predicted and the experimentally observed effect of metal yield stress and temperature on crack velocity is confirmed

Method for predicting molding defect in spinning machining

Abstract: PROBLEM TO BE SOLVED: To develop a spinning-machined product in a short development period at small development cost by calculating and predicting molding defects in spinning molding. SOLUTION: Meshes for FEM analysis representing a base material shape and a metal mold shape are prepared (11) and used, molding conditions are set, and drawing simulation of spinning machining by the FEM analysis by a dynamic explicit solution method is performed (13); and hydrostatic stress, equivalent stress, and equivalent strain for every unit time in a molding process are found (14), the value I of a decision parameter is found from the found hydrostatic stress, equivalent stress, and equivalent strain for every unit time by using an Oyane's theoretical crack decision expression (15), and on the basis of the found theoretical crack decision parameter value I, the occurrence of a molding defect is predicted.