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 >

Suzhen Wang¹, Yanpiao Zhang¹, Lu Zhang¹, Ning Cao^{2, *}, Chaoyi Pang³

CMC-Computers, Materials & Continua, Vol.56, No.3, pp. 415-431, 2018, DOI: 10.3970/cmc.2018.03716

Abstract Spark is a fast unified analysis engine for big data and machine learning, in which the memory is a crucial resource. Resilient Distribution Datasets (RDDs) are parallel data structures that allow users explicitly persist intermediate results in memory or on disk, and each one can be divided into several partitions. During task execution, Spark automatically monitors cache usage on each node. And when there is a RDD that needs to be stored in the cache where the space is insufficient, the system would drop out old data partitions in a least recently used (LRU) fashion to release more space. However,… More >

Hsin-Yu Chen¹, Nien-Ti Tsou^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 319-332, 2019, DOI:10.32604/cmes.2019.06447

Abstract Shape memory alloys has been widely applied on actuators and medical devices. The transformation temperature and microstructural evolution play two crucial factors and dominate the behavior of shape memory alloys. In order to understand the influence of the composition of the Ni-Ti alloys on the two factors, molecular dynamics was adopted to simulate the temperature-induced phase transformation. The results were post-processed by the martensite variant identification method. The method allows to reveal the detailed microstructural evolution of variants/phases in each case of the composition of Ni-Ti. Many features were found and having good agreement with those reported in the literature,… More >

X.S. He¹, Q.X. Liu¹, X.C. Huang², Y.M. Chen^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.3, pp. 159-169, 2015, DOI:10.3970/cmes.2015.108.159

Abstract This paper presented dynamic response analysis for an MEMS viscometer. The responses are governed by a set of differential equations containing fractional derivatives. The memory-free Yuan-Agrawal’s approach was extended to solve fractional differential equations containing arbitrary fractional order derivative and then a simple yet efficient numerical scheme was constructed. Numerical examples show that the proposed method can provide very accurate results and computational efforts can be significantly saved. Moreover, the numerical scheme was extended to solve problems with a nonlinear spring. The influences of the nonlinear parameters on the dynamic responses were also efficiently analyzed. The dependence of the angular… More >

Yuping Zhu^1,2, Tao Shi¹, Yuanbing Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.6, pp. 501-517, 2013, DOI:10.3970/cmes.2013.095.501

Abstract Single crystal ferromagnetic shape memory alloy is a kind of new intelligent materials, it shows obvious anisotropy. Micromechanics theory has been used to analyze the whole mechanical behaviors of this material. However, Eshelby’s tensor of this material which plays an important role has still not solved efficiently. Based on the existing micromechanics constitutive model, this paper analyzes the numerical calculation formula of Eshelby’s tensor of anisotropic ferromagnetic shape memory alloy. Adopting the way of Gauss integral, the optimal Gaussian integral points for different inclusion shapes and the corresponding numerical solution of Eshelby’s tensor are obtained.Furthermore, the influence of inclusion shapes… More >

Bingfei Liu¹, Guansuo Dui^2,3, Lijun Xue², Benming Xie¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.3, pp. 239-260, 2013, DOI:10.32604/cmes.2013.094.239

Abstract Analytical solutions are derived for the macroscopic behaviors of a Shape Memory Alloy (SMA) thick-walled cylinder subjected to internal pressure and radial temperature gradient. The Tresca transformation criterion and linear hardening are used. Equations are given for the radial and circumferential stresses, transformation strains and martensite volume fractions at both the elastic step and the transformation step. Numerical results are presented and in good agreement with the finite element simulations. More >

Lijun Xue¹, Guansuo Dui^1,2, Bingfei Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 1-16, 2013, DOI:10.3970/cmes.2013.093.001

Abstract The Functionally Graded Shape Memory Alloy (FG-SMA) is a new kind of functional materials which possesses the excellent properties of both Shape Memory Alloy (SMA) and Functionally Graded Material (FGM). A macro constitutive model of FG-SMA is established by using the theory of the mechanics of composites and the existing SMA model. With this macro constitutive model, the mechanical behavior of a FG-SMA beam composed by elastic material A and SMA subjected to pure bending is investigated. The loading processes including elastic process and phase transformation process are discussed in detail and the analytical solutions are obtained. What is more,… More >

Guanghui Shi¹, Qingsheng Yang^1,2, Xiaoqiao He^3,4, Kim Meow Liew³

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.5, pp. 339-358, 2013, DOI:10.3970/cmes.2013.090.339

Abstract In order to describe the thermomechanical deformation and shape memory effect of shape memory polymers (SMPs), a three-dimensional thermomechanical constitutive model that considers elastic, viscoelastic strain and thermal expansion is proposed for isotropic SMPs. A three-dimensional finite element procedure is developed by implementing the proposed constitutive model into the user material subroutine (UMAT) in ABAQUS program. Numerical examples are used to compare it with existing experimental data in a one dimensional case and to demonstrate the thermomechanical behavior of SMPs with 3D deformation. It is shown that the present constitutive theory and the finite element method can effectively simulate the… More >

Min Ki Kim¹, Seung Jo Kim²

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.4, pp. 297-332, 2012, DOI:10.3970/cmes.2012.084.297

Abstract Hybrid parallelization of multifrontal solution method and its parallel performances in a multicore distributed parallel computing architecture are represented in this paper. To utilize a state-of-the-art multicore computing architecture, parallelization of the multifrontal method for a symmetric multiprocessor machine is required. Multifrontal method is easier to parallelize than other direct solution methods because the solution procedure implies that the elimination of unknowns can be executed simultaneously. This paper focuses on the multithreaded parallelism and mixing distributed algorithm and multithreaded algorithm together in a unified software. To implement the hybrid parallelized algorithm in a distributed shared memory environment, two innovative ideas… More >

Bingfei Liu¹, Guansuo Dui^1,2, Yuping Zhu³

CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.3&4, pp. 247-276, 2011, DOI:10.3970/cmes.2011.078.247

Abstract A constitutive model considering the effect hydrostatic stresses induced by porosity on the macroscopic behavior of porous Shape Memory Alloys (SMAs) is developed in this paper. First, a unit-cell model is adopted to establish the constitutive relations for the porous SMAs with SMA matrix and the porosity taken to be voids. Dilatational plasticity theory is then generalized for the SMA matrix. Based on an approximation of the velocity field and the upper bound theory, an explicit yield function for the porous SMA is derived from micromechanical considerations. Finally, an example for the uniaxial response under compression of a porous Ni-Ti… More >