Qiufeng Yang¹, Xudong Li², Zhaowei Liu³, Feng Jin^1,*, Yilin Qu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-2, 2023, DOI:10.32604/icces.2023.09073

Abstract Compared to piezoelectric effects restricted to noncentrosymmetric crystalline structures, flexoelectric effects exist universally in all crystalline structures [1,2]. Meanwhile, some crystals, say silicon, are also semiconductive, which raises interest in studying the interactions between mechanical fields and mobile charges in semiconductors with consideration of piezoelectricity or flexoelectricity [3,4]. In order to explain these coupling effects, macroscopic theories on elastic semiconductors considering piezoelectricity or flexoelectricity were proposed by Yang and co-authors [5,6]. For piezoelectric semiconductors, the formulation of finite elements is relatively straightforward since the governing partial derivative equation (PDE) is twice-order. As for elastic semiconductors with consideration of flexoelectricity, it… More >

Mohamed Abdelsabour Fahmy^1,2,*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 931-944, 2021, DOI:10.32604/cmc.2021.018191

Abstract The main objective of this paper is to introduce a new theory called size-dependent thermopiezoelectricity for smart nanostructures. The proposed theory includes the combination of thermoelastic and piezoelectric influences which enable us to describe the deformation and mechanical behaviors of smart nanostructures subjected to thermal, and piezoelectric loadings. Because of difficulty of experimental research problems associated with the proposed theory. Therefore, we propose a new boundary element method (BEM) formulation and algorithm for the solution of such problems, which involve temperatures, normal heat fluxes, displacements, couple-tractions, rotations, force-tractions, electric displacement, and normal electric displacement as primary variables within the BEM… 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 >

Weiqiu CHEN

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.018.125

Abstract We will report a theory of surface piezoelectricity which governs a plane surface of a piezoelectric body. The piezoelectric surface may be endowed with different properties from the bulk material, and can account for the well-known surface effect which becomes increasingly important in micro- or nano-sized structures. In this study, the surface is treated as a piezoelectric thin layer of thickness h, and the state-space formulism is adopted to obtain the transfer relation between the state vectors at the top and bottom surfaces of the layer. The power series of the transfer matrix is then used, which can be truncated… More >

Cristiano Ubessi¹, Federico C. Buroni^2,*, Gabriel Hattori³, Andrés Sáez⁴, Rogério J. Marczak¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.1, pp. 104-104, 2019, DOI:10.32604/icces.2019.05420

Abstract Efficient three-dimensional infinite Green’s function and its first- and second-order derivatives for materials with piezoelectric coupling are studied in this paper. The procedure is based on an explicit solution recently introduced by the authors which presents three valuable characteristics: (i) it is explicit in terms of the Stroh’s eigenvalues, (ii) it remains well-defined when some Stroh’s eigenvalues are repeated (mathematical degeneracy) or nearly equal (quasi-mathematical degeneracy), and (iii) it is exact. Then, this solution is used to compute coefficients for a double Fourier series representation of the Green’s function and its derivatives. These Fourier expansion representations are realvariable which is… More >

Chih-Ping Wu, Jyh-Yeuan Lo, Jyh-Ka Chao¹

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 119-138, 2005, DOI:10.3970/cmc.2005.002.119

Abstract An asymptotic theory of doubly curved laminated piezoelectric shells is developed on the basis of three-dimensional (3D) linear piezoelectricity. The twenty-two basic equations of 3D piezoelectricity are firstly reduced to eight differential equations in terms of eight primary variables of elastic and electric fields. By means of nondimensionalization, asymptotic expansion and successive integration, we can obtain recurrent sets of governing equations for various order problems. The two-dimensional equations in the classical laminated piezoelectric shell theory (CST) are derived as a first-order approximation to the 3D piezoelectricity. Higher-order corrections as well as the first-order solution can be determined by treating the… More >

M. C. Ray¹, L. Dong², S. N. Atluri³

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.5, pp. 437-471, 2016, DOI:10.3970/cmes.2016.111.437

Abstract This paper is concerned with the development of new simple 4-noded locking-alleviated smart finite elements for modeling the smart composite beams. The exact solutions for the static responses of the overall smart composite beams are also derived for authenticating the new smart finite elements. The overall smart composite beam is composed of a laminated substrate conventional composite beam, and a piezoelectric layer attached at the top surface of the substrate beam. The piezoelectric layer acts as the actuator layer of the smart beam. Alternate finite element models of the beams, based on an "equivalent single layer high order shear deformation… More >

T. Lahmer¹, J. Ilg², R. Lerch²

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.2, pp. 105-126, 2015, DOI:10.3970/cmes.2015.106.105

Abstract In the recent years many publications appeared putting emphasis on the simulation-based identification of piezoelectric material parameters from electrical or mechanical measurements and combinations of them. By experience, one is aware of the importance of a single input parameter. However, it is not yet fully understood and in particular quantified to which extend missing knowledge in the single parameters (parameter uncertainty) influences the quality of the model's prognosis. In this paper, we adapt and apply variance-based sensitivity measures to models describing the piezoelectric effect in the linear case and derive global information about the single input parameter's sensitivities. More >

Ying Xu¹, Shuling Hu¹, Shengping Shen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.5, pp. 397-408, 2013, DOI:10.3970/cmes.2013.091.397

Abstract Flexoelectricity presents a strong size effect, and should not be ignored for nanodevices. In this paper, the flexoelectric effect is taken into account to investigate the electrostatic potential distribution in a bent flexoelectric semiconductive nanowire, and the numerical solution is obtained by using the finite difference method. The effect of donor concentration on the electrostatic potential are also investigated. The results show that, the flexoelectricity increases the value of the voltage on the cross section. The flexoelectric effect is varied with the size, i.e. when the radius of the nanowire is small the flexoelectric effect is significant. It is also… More >

B. Yang², V. K. Tewary³

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 165-178, 2006, DOI:10.3970/cmes.2006.015.165

Abstract Green's function (GF) modeling of defects may take effect only if the GF as well as its various integrals over a line, a surface and/or a volume can be efficiently evaluated. The GF is needed in modeling a point defect, while integrals are needed in modeling line, surface and volumetric defects. In a matrix of multilayered, generally anisotropic and linearly elastic and piezoelectric materials, the GF has been derived by applying 2D Fourier transforms and the Stroh formalism. Its use involves another two dimensions of integration in the Fourier inverse transform. A semi-analytical scheme has been developed previously for efficient… More >