A Novel BEM for Modeling and Simulation of 3T Nonlinear Generalized Anisotropic Micropolar-Thermoelasticity Theory with Memory Dependent Derivative

The main aim of this paper is to propose a new memory dependent derivative(MDD)theory which called threetemperature nonlinear generalized anisotropic micropolar-thermoelasticity.The system of governing equations of the problems associated with the proposed theory is extremely difficult or impossible to solve analytically due to nonlinearity,MDD diffusion,multi-variable nature,multi-stage processing and anisotropic properties of the considered material.Therefore,we propose a novel boundary element method(BEM)formulation for modeling and simulation of such system.The computational performance of the proposed technique has been investigated.The numerical results illustrate the effects of time delays and kernel functions on the nonlinear three-temperature and nonlinear displacement components.The numerical results also demonstrate the validity,efficiency and accuracy of the proposed methodology.The findings and solutions of this study contribute to the further development of industrial applications and devices typically include micropolar-thermoelastic materials.

Nonlinear Anisotropic Composite Biomechanical Modeling of Human Skin

A 3D nonlinear anisotropic composite biomechanical modeling of human skin was developed according to existing biomechanical experimental results,which can provide insights into the important structure-function relationship and parameters in skin tissue.A structural approach determines the macroscopic mechanical response of the skin tissue from its underlying structural components.The collagen fibers were embedded into a block of elastic gel matrix.The constitutive matrix of skin tissue consisted of both of collagen fiber and elastic gel block according to the rule that the collagen fibers were undulated with the ability to resist load only when completely straightened.The nonlinear and anisotropic mechanical responses were largely due to varying degree of fiber undulation.Statistical distributions were used to determine the extent of fiber undulation.The comparison of stress-strain plots between the modeling and experimental results showed the good coordination of the both.Some model parameters were discussed to compute the macroscopic mechanical response when the tissue block was subject to a simple deformation mode.

Bauschinger-Like Effect of AZ31 Magnesium Alloy Wide Sheet During the Straightening Process

The Bauschinger-like effect, which showed up in the straightening process of the AZ31 magnesium alloy wide sheet, was investigated through the multi-pass discrete three-point bending–unloading–bending(BUB) experiments. The stress variable, anisotropy, and asymmetry of tension and compression on the straightening process were corresponding to the Bauschingerlike effect. The Bauschinger-like effect in the initial, intermediate, and end of the straightening process was dominated by the twinning, detwinning, and dislocation induced by pyramidal < c + a > slip, respectively. Also, they were responsible for the transformation of the Bauschinger stress parameter(BSP) and Bauschinger energy parameter(BEP). Later, the anisotropic nonlinear kinematic hardening model(ANK model) to describe the Bauschinger-like effect was optimized and simplified.