A new phenomenological constitutive model is proposed to predict the mechanical behaviour of thermoplastics in current research. The and method determine parameters are introduced. In model, a transition function enable smooth flow stress behaviours under both small-strain large-strain conditions. validating with testing data Polyetheretherketone (PEEK) Polycarbonate (PC), it found that this ab...

Modeling the flow curves of materials at elevated temperatures is the first step in mathematical simulation of the hot deformation processes of them. In this work a comparative study was provided to examine the capability of three different constitutive equations in modeling the hot deformation flow curves of AZ91 magnesium alloy. For this, the Arrhenius equation with strain dependent constants...

The Sherwood-Frost constitutive model is widely used to predict the mechanical behavior of polymer materials, and it a very important material model. In this study, stress-strain curve high-density polyethylene (HDPE) with strain rate ranging from 935 5450 s−1 was obtained through split Hopkinson bar test device. Based on HDPE dynamic performance test, method for determining strain-rate paramet...

The purpose of this paper is to analysis the viscoelastic models under dynamic loading. A five-parameter model is chosen for study exhibits elastic, viscous, and retarded elastic response to shearing stress. The viscoelastic specimen is chosen which closely approximates the actual behavior of a polymer. The module of elasticity and viscosity coefficients are assumed to be space dependent i.e. f...

A new elastic-viscoplastic (EVP) constitutive model is proposed for the analysis of time-dependent behavior of clay. The proposed model is based on the bounding surface plasticity and the concept of viscoplastic consistency framework to establish continuous transition from plasticity to rate dependent viscoplasticity. Unlike the overstress based models, this model will meet the consistency cond...

underground caverns in rock salt deposits are the most secure disposal method and a type of gas-storing facility. gas storage plays a vital role in ensuring that a strategic relationship is secured between an established energy infrastructure provider and a midstream energy company. the fischells brook area is a pillow-shaped body of salts located in the st. george's bay area of southwest newfo...

To compute the stability of underground engineering, a constitutive model of surrounding rock must be identified. Many constitutive models for rock mass have been proposed. In this model identification study, a generalized constitutive law for an elastic-plastic constitutive model is applied. Using the generalized constitutive law, the problem of model identification is transformed to a problem...