Papers by Keyword: Elastic-Viscoplastic Material

Abstract: To further study the field of the mixed-mode interface crack tip under compression and shear, we analyze the problem on the quasi-static propagating of the interface crack theoretically and numerically.In this paper,we assumes that the artifical viscosity cofficient is in inverse proportion to power law of the plastic strain rate,and the stress of the interface crack possesses power law singularity. The viscosity of material,the friction touch effection of the crack-tip surface and the load hybrid parameter are considered. The asymptotic solution is established for elastic-viscoplastic field at the mixed-mode propagating crack-tip under comprission and shear.It is shown in numerical results and analysis that for the mixed-mode crack-tip field under compressing and shear is whole plastic without elastic unloaded section;viscosity effection is an important factor when propagating crack-tip field is studied; viscosity coefficient, mach number and singularity exponent are the control factors of singular field at the crack-tip.

Abstract: The existence of viscosity effect at the interface of double dissimilar materials has an important impact to the distribution of interface crack-tip field and the properties variety of the interface itself. The singularity and viscosity are considered in crack-tip, and the elastic-viscoplastic governing equations of double dissimilar materials at interface crack-tip field are established. The displacement potential function and boundary condition of interface crack-tip are introduced, and the numerical analysis of elstic-viscoplastic/rigid interface for mode I are worked out. The stress-strain fields are obtained at the crack-tip and the variation rules of solutions are discussed according to each parameter. The numerical results show that the viscosity effect is a main factor of interface propagating at crack-tip field, and the interface crack-tip is a viscoplastic field that is governed by viscosity coefficient、Mach number and singularity exponent.

Abstract: The existence of viscosity effect at the interface of double dissimilar materials has an important impact to the distribution of interface crack-tip field and the properties variety of the interface itself. The singular is considered in crack-tip, and the elastic-viscoplastic governing equations of double dissimilar materials at quasi-static propagating interface crack-tip field are established. The displacement potential function and boundary condition of interface crack-tip are introduced, and the numerical analysis of rigid-elastic viscoplastic interface for mode II are worked out. The stress-strain fields are obtained at the crack-tip and the variations of solutions are discussed according to each parameter. The numerical results show that the viscosity effect is a main factor of interface propagating crack-tip field, and the interface crack-tip is a viscoplastic field that is governed by viscosity coefficient、Mach number and singular factor.

Abstract: Under the assumption that the viscosity coefficient is in inverse proportion to the power law of the equivalent plastic strain rate. The friction touch effect between viscosity and crack-tip surfaces is considered, the asymptotic solution is established for elastic-viscoplastic field at the mixed-mode quasi static crack-tip under compression and shear. The numerical solution at crack-tip without stress and stain gap is obtained. The variation of numerical solution is discussed for the mixed-mode under compression and shear according to each parameter. Through numerical results and analysis for the mixed-mode crack-tip field under compressing and shear, it is whole plastic without elastic unloaded section, viscosity effect is an important factor when propagating crack-tip field.

Abstract: The viscosity of material is considered at propagating crack-tip. Under the assumption that the artificial viscosity coefficient is in inverse proportion to the power law of the plastic strain rate, an elastic-viscoplastic asymptotic analysis is carried out for moving crack-tip fields in power-hardening materials under plane-strain condition. A continuous solution is obtained containing no discontinuities. The variations of the numerical solution are discussed for mode I crack according to each parameter. It is shown that stress and strain both possess exponential singularity. The elasticity, plasticity and viscosity of material at the crack-tip only can be matched reasonably under linear-hardening condition. The tip field contains no elastic unloading zone for mode I crack.