Jie Qu, Bingye Xu, Quanlin Jin

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 21-22, 2011, DOI:10.3970/icces.2011.016.021

Abstract Large macro-micro coupled constitutive models, which describe metal flow and microstructure evolution during metal forming, are sometimes overparameterized with respect to given sets of experimental datum. This results in poorly identifiable or nonidentifiable model parameters. In this paper, a systemic parameter identification method for the large macro-micro coupled constitutive models is proposed. This method is based on the global and local identifiability analysis, in which two identifiability measures are adopted. The first accounts for the sensitivity of model results to single parameters, and the second accounts for the degree of near-linear dependence of sensitivity functions of parameter subsets. The global… More >

Amiya Kr. Samanta¹, Somnath Ghosh²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.3, pp. 143-150, 2009, DOI:10.3970/icces.2009.009.143

Abstract This paper deals with the implementation of hypo-elasticity based 3D constitutive model on Reinforced Concrete (RC) frame employing finite element technique, which uses lower order isometric solid elements HCiS18 with enhanced assumed strain (EAS) formulation to evaluate load-deformation, internal stresses produced in the elastic regime. Due attention has been paid to model concrete and the reinforcing steel with different physical and mechanical properties, which are combined together to represent its composite behaviour accurately in perfect bond situation. An in-house FORTRAN computer code has been developed for the purpose. The results of the finite element analysis are presented, compared and discussed. More >

H. N. Silva¹, J. B. Soares¹, E. Parente Jr.², P. C. Sousa¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.7, No.4, pp. 181-188, 2008, DOI:10.3970/icces.2008.007.181

Abstract The numerical implementation of the time-dependent linear viscoelastic constitutive model using object-oriented programming is discussed here. This paper is divided in two main parts: (i) a brief discussion of the numerical integration of linear viscoelastic constitutive equations, including the use of Prony series for characterization of viscoelastic materials (e.g. asphalt pavement surfaces) and (ii) the class organization and methods implemented in viscoelastic related classes of an object-oriented framework. The implementation is part of an ongoing development Finite Element (FE) computer system for pavement analysis and research. More >

T. Tanaka¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 251-256, 2007, DOI:10.3970/icces.2007.004.251

Abstract The viscoplastic constitutive relations with kinematic strain hardening-softening model for geomaterials are developed. The constitutive models include strain-rate dependent properties based on the thoery by Duvaut-Lions. The dynamic relaxation method for static problems and the dynamic analysis for earthquake responses are applied to boundary value problems using finite element methods. More >

X. Liu, A. Scarpas¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 57-74, 2005, DOI:10.3970/cmes.2005.009.057

Abstract Numerical investigations of strain localization have been performed on 3D dense fully saturated sand specimens subjected to triaxial loading and simultaneous inflow or outflow conditions. The role of the water suction field on the formation and evolution of strain localization is addressed computationally. It has been shown that, in a porous medium, the fluid (water) phase plays indeed an important role in strain localization. The formation and evolution of strain localization are influenced both by the material behaviour of the solid component and the interaction between components. In this contribution, after a presentation of the incremental formulation of the coupled… More >

Lilan Gao^1,2,*, Qingxian Yuan^1,2, Ruixin Li^3,*, Lei Chen^1,2, Chunqiu Zhang^1,2, Xizheng Zhang^1,2

Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 85-98, 2018, DOI: 10.3970/mcb.2018.00329

Abstract Silk fibroin-typeⅡcollagen scaffold was made by 3D printing technique and freeze-drying method, and its mechanical properties were studied by experiments and theoretical prediction. The results show that the three-dimensional silk fibroin-typeⅡ collagen scaffold has good porosity and water absorption, which is (89.3%+3.26%) and (824.09%+93.05%), respectively. With the given strain value, the stress of scaffold decreases rapidly firstly and then tends to be stable during the stress relaxation. Both initial and instantaneous stresses increase with increase of applied strain value. The creep strains of scaffold with different stress levels show the two stages: the rapidly increasing stage and the second stable… More >

B. Chen^1,2, X. Peng^1,2,3, X. Chen^1,2, J. Wang⁴, H. Wang⁴, N. Hu^1,5,6

CMC-Computers, Materials & Continua, Vol.30, No.2, pp. 145-176, 2012, DOI:10.3970/cmc.2012.030.145

Abstract A three-dimensional phenomenological model for coupled transformation and plastic behavior of shape memory alloys (SMAs) is presented. The strain is separated into elastic, thermal, transformation and plastic strain parts, and two yield functions are adopted to describe respectively the transformation and plastic deformation. An integral algorithm is suggested, including the update of the stress and the tangent stiffness. Numerical examples and the comparison with experimental results show that the proposed approach can well describe the behavior of the SMAs subjected to complicated thermal-mechanical loading, demonstrating the validity of the model in the description of the constitutive behavior of SMAs, including… More >

Shen Shang and Gun Jin Yun^1,1

CMC-Computers, Materials & Continua, Vol.27, No.1, pp. 55-72, 2012, DOI:10.3970/cmc.2012.027.055

Abstract In this paper, the Self-Optimizing Inverse Method (Self-OPTIM) has been experimentally verified by identifying constitutive parameters solely based on prescribed boundary loadings without full-field displacements. Recently the Self-OPTIM methodology was developed as a computational inverse analysis tool that can identify parameters of nonlinear material constitutive models. However, the methodology was demonstrated only by numerically simulated testing with full-field displacement fields and prescribed boundary loadings. The Self-OPTIM is capable of identifying parameters of the chosen class of material constitutive models through minimization of an implicit objective function defined as a function of full-field stress and strain fields in the optimization process.… More >

Ying Xiao¹, Hao-Miao Zhou^1,2,3, Xiao-Wei Ou¹, Chao Li¹

CMC-Computers, Materials & Continua, Vol.27, No.1, pp. 1-22, 2012, DOI:10.3970/cmc.2012.027.001

Abstract Considering the complex strongly nonlinear coupling characteristic of the magnetostrictive strain and magnetization under the excitation of the bias magnetic field and the pre-stress in the giant magnetostrictive material, this paper adopts the nonlinear magnetostrictive constitutive model and the equivalent circuit method to establish a strongly nonlinear resonant magnetoelectric (ME) effect theoretical model for the ME laminate composites compounding by the giant magnetostrictive material and the piezoelectric material. For the L-T mode magnetostrictive/piezoelectric/magnetostrictive (MPM) ME laminate, the predicted results coincide well with the experiment results of the resonant frequency and the resonant ME field coefficient varying with the external magnetic… More >

R. Chen¹, X. Han^1,2, J. Liu¹, W. Zhang¹

CMC-Computers, Materials & Continua, Vol.25, No.2, pp. 135-158, 2011, DOI:10.3970/cmc.2011.025.135

Abstract In this paper, a computational inverse technique is presented to determine the constitutive parameters of concrete based on the penetration experiments. In this method, the parameter identification problem is formulated as an inverse problem, in which the parameters of the constitutive model can be characterized through minimizing error functions of the penetration depth measured in experiments and that computed by forward solver LS-DYNA. To reduce the time for forward calculation during the inverse procedure, radial basis function approximate model is used to replace the actual computational model. In order to improve the accuracy of approximation model, a local-densifying method combined… More >