Hao Sun¹, Timothy Eswothy¹, Kerlin P. Robert¹, Jiaoyan Li², L. G. Zhang¹, James D. Lee^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 75-75, 2019, DOI:10.32604/mcb.2019.07090

Abstract Most biological phenomena commonly involve with mechanics. In this work, we proposed an innovative model that tumor is considered as a pyroelastic medium consisting of two parts: solid and fluid. The variation of solid part depends on whether the drug has been effectively delivered to the tumor site. We derived the governing equations of the tumor, in which large deformation is incorporated. Meanwhile, the finite element equations for coupled displacement field and pressure field are formulated. We proposed two sets of porosity and growth tensor. In both cases the continuum theory and FEM are accompanied by accurate numerical simulations. To… More >

Kerlin P. Robert¹, Jiaoyan Li², James D. Lee^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 74-74, 2019, DOI:10.32604/mcb.2019.07125

Abstract This presentation focuses on the new and upcoming concept of 4D printing and its vast scope and importance in the research and development in industry. The 3D printing object is considered as a layered structure. Each layer may have different orientation. Therefore each layer may behave differently under the change of its environment. We formulate the theoretical shape changing process of 4D printing resulted from (I) the biological growth or swelling, (II) the change of temperature, and (III) the effect of electric field on piezoelectric material of the 3D printing product. Then we illustrate this theory visually through finite element… More >

LI Tao, Gao Jian, ZHANG Yi-ping

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.018.075

Abstract This paper presents a method for the large strain consolidation analysis of soft-clay road embankment with stochastic parameters to random excitation. Based on the large strain theory of continuum material, Biot consolidation theory and Neumann stochastic finite element method (NSFEM), the large strain consolidation NSFEM (LSC-NSFEM) has been established. A program of LSC-NSFEM is designed to analyze soft-clay road embankment. The residue iteration method is used to deal with the nonlinear fluctuating part of stiffness matrix, and the approximate algorithm of the fluctuating part of stiffness matrix is designed to improve LSC-NSFEM program efficiency. More >

H. Wang, P.D. Wu, K.W. Neale

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 23-24, 2011, DOI:10.3970/icces.2011.016.023

Abstract Large strain homogeneous simple shear of Hexagonal Close Packed (HCP) polycrystals is first studied numerically. The analyses are based on the classical Taylor model and the Visco-Plastic Self-Consistent (VPSC) model with various Self-Consistent Schemes (SCSs). In these polycrystal plasticity models, both slip and twinning contribute to plastic deformations. The simple shear results are then extended to the case of solid circular bars under large strain fixed-end torsion, where it is assumed that the solid bar has the same mechanical properties as the element analyzed for large strain simple shear. It is shown that the predicted second-order axial force is very… More >

Igor Karšaj¹, Carlo Sansour², Jurica Sorić¹

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.1, pp. 45-60, 2005, DOI:10.3970/cmes.2005.008.045

Abstract In this paper, a free energy-based formulation incorporating the effect of kinematic hardening is proposed. The formulation is able to reproduce symmetric expressions for the back stress while incorporating the multiplicative decomposition of the deformation gradient. Kinematic hardening is combined with isotropic hardening where an associative flow rule and von Mises yield criterion are applied. An accurate and trivial wise objective integration algorithm employing the exponential map is developed. In order to ensure a high convergence rate in the global iteration approach, an algorithmic tangent operator is derived. The computational algorithm is implemented and applied to a shell finite element… More >

P.D.Gosling^1,2, L. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.3, pp. 203-252, 2011, DOI:10.3970/cmes.2011.071.203

Abstract The analysis of a continuum membrane by means of a discrete network of cables or bars is an efficient and readily tractable approach to the solution of a complex mechanics problem. However, is so doing, compromises are made in the quality of the approximation of the strain field. It is shown in this paper that the original form of the cable-analogy continuum triangle formulation is degraded by an inherent assumption of small strains in the underlying equations, in which the term ßmall" is shown to be "negligibly small". A revised version of this formulation is proposed in which a modification… More >

M. Tanaka^1,2, H. Noguchi¹, M. Fujikawa^3,4, M. Sato³, S. Oi³, T. Kobayashi³, K. Furuichi⁵, S. Ishimaru⁵, C. Nonomura⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.3, pp. 265-290, 2010, DOI:10.3970/cmes.2010.062.265

Abstract This paper describes the development of a proper constitutive model of woven fabrics and its implementation in nonlinear finite shell elements in order to simulate the large deformation behavior of cloth. This work currently focuses on a macroscopic continuum constitutive model that is capable of capturing the realistic mechanical behavior of cloth that is characterized by two families of yarns, i.e., warp and weft. In this study, two strategies are considered. One is a rebar layer model and the other is a polyconvex anisotropic hyperelastic material model. The latter avoids non-physical behavior and can consider the effect of the interaction… More >

Y. Başar, O. Kintzel¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.2, pp. 217-230, 2003, DOI:10.3970/cmes.2003.004.217

Abstract The objective of this contribution is the development of a finite element model for finite rotation and large strain analysis of thin walled shells involving geometry intersections. The shell configuration is described by a linear polynomial in the thickness coordinate. The director of the shell is multiplicatively decomposed into a stretching parameter and an inextensible unit vector whose rotation is accomplished by an updated-rotation formulation. A rotation vector with three independent components is used throughout the shell which permits advantageously to consider smooth shells and compound shells by a unified procedure. This formulation is introduced into an isoparametric four-node element.… More >

H. Wang¹, Y. Wu², P.D. Wu¹, K.W. Neale³

CMC-Computers, Materials & Continua, Vol.19, No.3, pp. 255-284, 2010, DOI:10.3970/cmc.2010.019.255

Abstract Large strain homogeneous simple shear of Hexagonal Close Packed (HCP) polycrystals is first studied numerically. The analyses are based on the classical Taylor model and the Visco-Plastic Self-Consistent (VPSC) model with various Self-Consistent Schemes (SCSs). In these polycrystal plasticity models, both slip and twinning contribute to plastic deformations. The simple shear results are then extended to the case of solid circular bars under large strain fixed-end torsion, where it is assumed that the solid bar has the same mechanical properties as the element analyzed for large strain simple shear. It is shown that the predicted second-order axial force is very… More >