Dye-Zone A. Chen, Gang Chen^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3005

Abstract We present a calculation of the thermally generated electromagnetic flux propagating along the in-plane direction of a polar, thin film. The approach is based on fluctuational electrodynamics and the fluctuation-dissipation theorem. We find that for silicon carbide films between 5 nm and 100 nm thick, the thinner films transport more in-plane flux due to the long propagation length of the anti-symmetric surface phonon-polariton mode. Comparison of results obtained from the fluctuation-dissipation approach and the kinetic theory approach shows favorable agreement. More >

Yunjiang Wang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09979

Abstract It is a textbook knowledge that the mechanical properties of crystalline solids are determined by the performances of their defects under certain circumstances of external stress and temperature. However, such a belief in crystals meets difficulty in amorphous solids, in which the concept of defect is hard to define. In this talk, I would like to talk about the unusual structure-property of amorphous metals from three different perspectives – in terms of their structural, vibrational and deformation characteristics. We try to build a super structure-property relationship in the general amorphous solids by machine learning strategy after we realized that their… More >

A.L. Chen, Y.S. Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 239-244, 2008, DOI:10.3970/icces.2008.005.239

Abstract Band gaps and localization phenomenon for both in-plane and anti-plane elastic waves propagating in 2D ordered and disordered phononic crystals are studied in this paper. The localization of wave propagation due to random disorder is discussed by introducing the concept of the localization factor which is calculated by the plane-wave-based transfer-matrix method. More >

Tsung-Tsong Wu¹, Tzung-Chen Wu¹, Jin-Chen Hsu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 9-10, 2009, DOI:10.3970/icces.2009.010.009

Abstract Recently, propagation of bulk and surface acoustic waves in periodic structures called phononic crystals (PCs) has attracted a lot of interests. The existence of band gaps, the frequency ranges in which acoustic wave propagation is forbidden, in such periodic structures has demonstrated many potential applications to acoustic-wave devices, such as filters, resonators, efficient acoustic waveguides, etc.
In this paper, Lamb wave propagation in a thin plate with a periodic stubbed surface is investigated numerically and experimentally. A detailed evolution of how the band structure form the complete band gaps as the increase of the stub height is studied numerically using… More >

Linli Zhu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.1, pp. 116-116, 2019, DOI:10.32604/icces.2019.05318

Abstract Low-dimensional semiconductor structures such as nanofilms and nanowires have stimulated considerable interest due to their potential applications in nanoelectronic or nanomechanical devices. In this presentation, the effects of pre-stress field and surface stress on the phonon and thermal/electrical properties for semiconductor nanostructures are investigated theoretically. The continuum elastic model is employed to calculate the spatially confined phonon properties. The acoustoelastic effects and surface energy effects are taken into account in calculating the phonon properties of nanostructures. Since the thermal and electric properties are associated with phonon properties of semiconductors, the phonon thermal conductivity, electron-acoustic phonon scattering rate and the carrier… More >

V.K. Tewary¹, M. D. Vaudin²

CMC-Computers, Materials & Continua, Vol.25, No.3, pp. 265-290, 2011, DOI:10.3970/cmc.2011.025.265

Abstract A semicontiuum Green's-function-based model is proposed for analysis of averaged mechanical characteristics of Si_xGe_{1 - x}. The atomistic forces in the model are distributed at discrete lattice sites, but the Green's function is approximated by the continuum GF in the far field and by the averaged lattice GF in the near field. Averaging is achieved by replacing Si and Ge atoms by identical hypothetical atoms that are x fraction Si and (1-x) fraction Ge. The parameters of the model are derived using the atomistic model from the interatomic potential between the hypothetical atoms. The interatomic potential is obtained from the… More >

Mao Liu^1,2, Jiawei Xiang¹, Haifeng Gao¹, Yongying Jiang¹, Yuqing Zhou¹, Fengping Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.5, pp. 425-436, 2014, DOI:10.3970/cmes.2014.097.425

Abstract A wavelet finite element method (WFEM) is developed to analyze the dispersion relation for one-dimensional phononic crystals (1DPCs). In order to calculate the band gaps (BGs) of 1DPCs, the wavelet finite element model is constructed using a slender beam element based on B-spline wavelet on the interval (BSWI). Combining with the Bloch-Floquet theorem and ω(k) technique, the model will be simplified as a simple eigenproblem. The performance of the proposed method has been numerically verified by one numerical example. More >

H.F. Gao¹, T. Matsumoto¹, T. Takahashi¹ and H. Isakari¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.4, pp. 283-301, 2013, DOI:10.3970/cmes.2013.090.283

Abstract By its very basis, the block Sakurai-Sugiura (SS) method may be applied to solving nonlinear eigenvalue problem formulated by boundary integral equation. In this paper, the methodology of BEM combined with the block SS method is applied to the computation of band structures of phononic structures for acoustic problems. Since the conventional boundary integral equation yields the real fictitious eigenfrequencies when it is applied to an exterior problem of scatters, Burton-Miller’s method is employed to remove the real fictitious eigenfrequencies resulted by the boundary of the scatterers. The application of the method is demonstrated through analyses of band structures of… More >

Mei-Jiau Huang¹, Tung-Chun Tsai¹, Liang-Chun Liu^1,2, Ming-shan Jeng², Chang-Chung Yang²

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.2, pp. 107-130, 2009, DOI:10.3970/cmes.2009.042.107

Abstract We develop a Monte-Carlo simulator for phonon transport in nanostructured semiconductors, which solves the phonon Boltzmann transport equation under the gray medium approximation. Proper physical models for the phonon transmission/reflection at an interface between two different materials and proper numerical boundary conditions are designed and implemented carefully. Most of all, we take advantage of geometric symmetry that exists in a system to reduce the computational amount. The validity and accuracy of the proposed MC solver was successfully verified via a 1D transient conduction problem and the cross-plane (1D) and in-plane (2D) phonon transport problems associated with Si/Ge superlattice thin films. More >

Zhi-Zhong Yan^1,2, Yue-Sheng Wang^1,3, Chuanzeng Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.38, No.1, pp. 59-88, 2008, DOI:10.3970/cmes.2008.038.059

Abstract In this paper, a numerical method based on the wavelet theory is developed for calculating band structures of 2D phononic crystals consisting of general anisotropic materials. After systematical consideration of the appropriate choice of wavelets, two types of wavelets, the Haar wavelet and Biorthogonal wavelet, are selected. Combined with the supercell technique, the developed method can be then applied to compute the band structures of phononic crystals with point or line defects. We illustrate the advantages of the method both mathematically and numerically. Particularly some representative numerical examples are presented for various material combinations (solid-solid, solid-fluid and fluid-fluid) with complex… More >