In this paper instability of planar anisotropic sheet metal during a few forming processes is investigated for the first time. For this reason components of the constitutive tangent tensor for planar anisotropic sheets are developed. By using the above tensor location of necking is predicted. Direction of the shear band is also predicted using the acoustic tensor. A finite element program is pr...

Background: There is no consistent data on the mechanical properties of sheep intestine. OBJECTIVES: We performed a series of biaxial strain measurement experiments and extracted the constitutive model to describe the mechanical characteristics of the sheep intestinal tissue. METHODS: Eleven specimens were obtained freshly from sacrificed  sheep and the planar biaxial tests were performed on th...

A framework for development of constitutive models based on semi-micromechanical aspects of plasticity is proposed. The resulting of this model for material employed friction type failure criterion, sub-loading surface, and associated flow rule. This model is capable of predicting effects of the rotation of principal stress/strain axes and consequent plastic flow, induced anisotropy of strength...

When an anisotropic material is subject to creep conditions and a complex state of stress, an anisotropic creep damage behavior is observed. Previous research has focused on the anisotropic creep damage behavior of isotropic materials but few constitutive models have been developed for anisotropic creeping solids. This paper describes the development of a new anisotropic tertiary creep damage c...

A new elasto-plastic constitutive model for jointed rock mass, which can consider the persistence ratio in different visual angle and anisotropic increase of plastic strain, is proposed. The proposed the yield strength criterion, which is anisotropic, is not only related to friction angle and cohesion of jointed rock masses at the visual angle but also related to the intersection angle between ...

A constitutive multi-laminate based elastic-plastic model developed to be capable of accounting induced anisotropic behavior of granular material such as sand. The fabric feature or grain orientation characteristic effects through medium are considered in a rational way under any complex stress path, including cyclic loading. The salient feature of the developed model is a non-associative on pl...

Many rubber like materials present a stress-softening phenomenon known as Mullins effect. It is characterized by a difference of behavior between the first and second loading and by a residual strain after a first loading. Moreover according to the literature this stress softening is anisotropic. A new constitutive equation is proposed. It relies on the decomposition of the macromolecular netwo...

Abstract: In order to solve the convergence problem of concrete constitutive in the softening phase, an anisotropic nonlinear elastic constitutive model (ANECM) was proposed, which was developed based on the uniaxial concrete constitutive relation in the Chinese code for design of concrete structures (GB 50010-2010). The user material subroutine (UMAT) based on ANECM is developed in ABAQUS soft...