Xiuqing Qian¹, Yanping Cao², Jianyu Zhang¹, Dierk Raabe², Zhenhan Yao³, Binjun Fei¹

CMC-Computers, Materials & Continua, Vol.7, No.1, pp. 33-42, 2008, DOI:10.3970/cmc.2008.007.033

Abstract In this work, an inverse approach based on depth-sensing instrumented indentation tests is proposed to determine the Young's modulus, yield strength and strain hardening exponent of the materials for which the elastoplastic part of the stress-strain curve can be described using a power function. Numerical verifications performed on typical engineering metals demonstrate the effectiveness of the new method. The sensitivity of the method to data noise and some experimental uncertainties are also discussed, which may provide useful information for the application of the method in practice. More >

M. Timmel¹, M. Kaliske¹, S. Kolling², R. Mueller³

CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 161-172, 2007, DOI:10.3970/cmc.2007.005.161

Abstract A damage approach based on a material model with microstructural evolution is presented. In contrast to phenomenological constitutive laws, the material response is given by mechanisms at the microscale. At first, a micromechanical substructure is chosen, which represents the overall material behaviour. Then the system is described using a micromechanical model. A geometrical modification of the microstructure is allowed to minimize the total energy. Consequently, the global stiffness is reduced. In this context, thermodynamical considerations are based on configurational forces. With the help of the discussed approach, void growth phenomena of materials, which lead to softening behaviour, can be taken… More >

S. Smaoui¹, A. Ben Hamida¹, I. Djeran-Maigre², H. Dumontet¹

CMC-Computers, Materials & Continua, Vol.4, No.3, pp. 153-162, 2006, DOI:10.3970/cmc.2006.004.153

Abstract An iterative homogenization approach is proposed in order to predict the nonlinear hydro-mechanical behaviour of porous media. This process is coupled to classical and modified secant extended methods and linear homogenization predictive schemes. At convergence of the iterative process, same equivalent behaviour is obtained for any secant method, any simplified homogenization used for the linear comparison material and for any initial porosity of the media. An application to the study of the nonlinear behaviour of clayey sediments is presented. The model parameters quantification is based on oedometric experimental results for different clays. More >

Chih-Ping Wu¹, Yun-Siang Syu

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 87-108, 2006, DOI:10.3970/cmc.2006.004.087

Abstract Based on the three-dimensional (3D) piezoelectricity, we presented asymptotic solutions for multilayered piezoelectric hollow cylinders using the method of perturbation. The material properties in the general formulation are firstly regarded to be heterogeneous through the thickness, and then specified as the layerwise step functions in the cases of multilayered cylinders. The transverse normal load and normal electric displacement are respectively applied on the lateral surfaces of the cylinders. The boundary conditions of cylinders are considered to be simply supported at the two edges. In the formulation the twenty-two basic equations of piezoelectricity are reduced to eight differential equations in terms… More >

L. Gornet¹, S. Marguet², G. Marckmann³

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 63-74, 2006, DOI:10.3970/cmc.2006.004.063

Abstract The purpose of the present study is to determine the components of the effective elasticity tensor and the failure properties of Nomex^® honeycomb cores. In order to carry out this study, the NidaCore software, a program dedicated to Nomex®Cores predictions, has been developed using the Finite Element tool Cast3M-CEA. This software is based on periodic homogenization techniques and on the modelling of structural instability phenomena. The homogenization of the periodic microstructure is realized thanks to a strain energy approach. It assumes the mechanical equivalence between the microstructures of a RVE and a similar homogeneous macroscopic volume. The key point of… More >

Shang Zhang^{1, *}, Seyedmehdi Karimi², Shahaboddin Shamshirband^{3, 4, *}, Amir Mosavi^5,6

CMC-Computers, Materials & Continua, Vol.58, No.2, pp. 567-583, 2019, DOI:10.32604/cmc.2019.02795

Abstract In the process of eliminating variables in a symbolic polynomial system, the extraneous factors are referred to the unwanted parameters of resulting polynomial. This paper aims at reducing the number of these factors via optimizing the size of Dixon matrix. An optimal configuration of Dixon matrix would lead to the enhancement of the process of computing the resultant which uses for solving polynomial systems. To do so, an optimization algorithm along with a number of new polynomials is introduced to replace the polynomials and implement a complexity analysis. Moreover, the monomial multipliers are optimally positioned to multiply each of the… More >

Ying Xiao^1,2, Haomiao Zhou¹, Xiaofan Gou^2,*

CMC-Computers, Materials & Continua, Vol.54, No.3, pp. 209-228, 2018, DOI:10.3970/cmc.2018.054.209

Abstract In order to predict the performance of magnetostrictive smart material and push its applications in engineering, it is necessary to build the constitutive relations for the magnetostrictive material Galfenol. For Galfenol rods under the action of the pre-stress and magnetic field along the axial direction, the one-dimensional nonlinear magneto-mechanical coupling constitutive model is proposed based on the elastic Gibbs free energy, where the Taylor expansion of the elastic Gibbs free energy is made to obtain the polynomial forms. And then the constitutive relations are derived by replacing the polynomial forms with the proper transcendental functions based on the microscopic magneto-mechanical… More >

Zihao Yang¹, Liang Ma², Qiang Ma³, Junzhi Cui^1,4, Yufeng Nie¹, Hao Dong¹, Xiaohong An⁵

CMC-Computers, Materials & Continua, Vol.53, No.3, pp. 219-248, 2017, DOI:10.32604/cmc.2017.053.235

Abstract This paper reports a multiscale analysis method to predict the thermo-mechanical coupling performance of composite structures with quasi-periodic properties. In these material structures, the configurations are periodic and the material coefficients are quasi-periodic, i.e., they depend not only on the microscale information but also on the macro location. Also, a mutual interaction between displacement and temperature fields is considered in the problem, which is our particular interest in this study. The multiscale asymptotic expansions of the temperature and displacement fields are constructed and associated error estimation in nearly pointwise sense is presented. Then, a finite element-difference algorithm based on the… More >

L.S. Melro^1,2, L.R. Jensen¹

CMC-Computers, Materials & Continua, Vol.53, No.2, pp. 109-127, 2017, DOI:10.3970/cmc.2017.053.111

Abstract Molecular dynamics simulations were applied in order to calculate the Young’s modulus of graphene functionalized with carboxyl, hydroxyl, carbonyl, hydrogen, methyl, and ethyl groups. The influence of the grafting density with percentages of 3, 5, 7, and 10% and the type of distribution as a single cluster or several small clusters were also studied. The results show that the elastic modulus is dependent on the type of functional groups. The increasing coverage density also evidenced a decrease of the Young’s modulus, and the organization of functional groups as single cluster showed a lesser impact than for several small clusters. Furthermore,… More >

H. Khellafi¹, H.M. Meddah¹, B. Ould Chikh¹, B. Bouchouicha², M. Benguediab², M. Bendouba³

CMC-Computers, Materials & Continua, Vol.49-50, No.1, pp. 31-45, 2015, DOI:10.3970/cmc.2015.049.031

Abstract The polyvinyl chloride PVC is a polymer material widely used for a large variety of applications. The present work focuses on the identification of the physical processes responsible for the mechanical properties of the PVC containing different crystallinities rate applied in large deformation and different strain rates. In order to understand the behavior of the PVC, a thermodynamic modeling is needed. Therefore, the contribution of this approach was demonstrated by experiment and numerical modeling. This comparative study demonstrates that the proposed model provides better agreement with experimental evidence. More >