Leiting Dong^1,2, Ahmed S. El-Gizawy³, Khalid A. Juhany³, Satya N. Atluri²

CMC-Computers, Materials & Continua, Vol.41, No.3, pp. 163-192, 2014, DOI:10.3970/cmc.2014.041.163

Abstract Following previous work of [Dong, El-Gizawy, Juhany, Atluri (2014)], a simple locking-alleviated 3D 8-node mixed-collocation C0 finite element (denoted as CEH8) is developed in this study, for the modeling of functionally-graded or laminated thick-section composite plates and shells, without using higher-order or layer-wise zig-zag plate and shell theories which are widely popularized in the current literature. The present C0 element independently assumes an 18-parameter linearly-varying Cartesian strain field. The independently assumed Cartesian strains are related to the Cartesian strains derived from mesh-based Cartesian displacement interpolations, by exactly enforcing 18 pre-defined constraints at 18 pre-selected collocation points. The constraints are rationally… More >

Chih-Ping Wu^1,2, Ruei-Yong Jiang¹, Sheng-Yao Tu¹

CMC-Computers, Materials & Continua, Vol.41, No.2, pp. 111-152, 2014, DOI:10.3970/cmc.2014.041.111

Abstract Exact three-dimensional stability and free vibration analyses of simply-supported, multilayered functionally graded material (FGM) circular hollow cylinders and laminated composite ones under axial compression are presented. The material properties of each FGM layer are assumed to obey a power-law distribution of the volume fractions of constituents through the thickness coordinate. The Pagano method, which is based on the principle of virtual displacement and is conventionally used for the analysis of laminated composite structures, is modified to be feasible for the study of multilayered FGM cylinders, in which Reissner's mixed variational theorem, the successive approximation and transfer matrix methods, and the… More >

Jung Soo Lee¹, Sung Yong Park², Keunhee Cho², Jeong-Rae Cho², Seung Hee Kwon^1,3

CMC-Computers, Materials & Continua, Vol.41, No.2, pp. 85-110, 2014, DOI:10.3970/cmc.2014.041.085

Abstract The objective of this study is to investigate the differences between the tensile stress-crack opening relationships of the small size notched beam and the real size beam which were made of two ultra-high performance fiber reinforced concretes (UHPFRCs) having different volume fractions and lengths of fibers. The stress-crack opening relationships of two UHPFRCs were first obtained from the inverse analysis for the small size notched beam tests. In addition, the three types of real size beams were manufactured for each mix: (1) plain beam, (2) beam with tensile reinforcement, and (3) beam with both tensile and compressive reinforcements. The flexural… More >

H. Zheng^1,2, X. Peng^1,2,3,4, N. Hu^1,3,5

CMC-Computers, Materials & Continua, Vol.41, No.1, pp. 55-84, 2014, DOI:10.3970/cmc.2014.041.055

Abstract The Shakedown of a functionally graded (FG) Bree plate subjected to coupled constant mechanical loading and cyclically varying temperature is analyzed with more accurate approaches and optimized with the genetic algorithm method. The shakedown theorem takes into account material hardening. The variation of the material properties in the thickness of a FG Bree plate is characterized with a piecewise exponential distribution, which can replicate the actual distribution with sufficient accuracy. In order to obtain the best distribution of the mechanical properties in the FG plate, the distribution of the reinforcement particle volume fraction is optimized with the genetic algorithm (GA).… More >

Qiubao Ouyang¹, Di Zhang^1,2, Xinhai Zhu³, Zhidong Han³

CMC-Computers, Materials & Continua, Vol.41, No.1, pp. 37-54, 2014, DOI:10.3970/cmc.2014.041.037

Abstract The present work is to investigate the failure mechanisms in the deformation of silicon carbide (SiC) particle reinforced aluminum Metal Matrix Composites (MMCs). To better deal with crack growth, a new numerical approach: the MLPG-Eshelby Method is used. This approach is based on the meshless local weak-forms of the Noether/Eshelby Energy Conservation Laws and it achieves a faster convergent rate and is of good accuracy. In addition, it is much easier for this method to allow material to separate in the material fracture processes, comparing to the conventional popular FEM based method. Based on a statistical method and physical observations,… More >

Chein-Shan Liu¹, Satya N. Atluri²

CMC-Computers, Materials & Continua, Vol.41, No.1, pp. 1-36, 2014, DOI:10.3970/cmc.2014.041.001

Abstract In this paper, we adopt the viewpoint of a nonlinear complementarity problem (NCP) to derive an index-one differential algebraic equations (DAEs) system for the problem of elastic-plastic wave propagation in an elastic-plastic solid undergoing small deformations. This is achieved by recasting the pointwise complementary trio in the elastic-plastic constitutive equations into an algebraic equation through the Fischer-Burmeister NCP-function. Then, for an isotropicallyhardening/ softening material under prescribed impulse loadings on a thin-walled tube with combined axial-torsional stresses, we can develop a novel algorithm based on the Lie-group differential algebraic equations (LGDAE) method to iteratively solve the resultant DAEs at each time… More >

Xue-Qian Fang^1,2, Hong-Wei Liu¹, Yong-Mao Zhao¹, Guo-Quan Nie^1,1 and Jin-Xi Liu¹

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 145-164, 2014, DOI:10.3970/cmc.2014.040.145

Abstract Electro-elastic surface/interface around nano-sized piezoelectric inclusions shows great effect on the response of piezoelectric nano-structures. In this paper, a theoretical model is proposed to examine the surface/interface effect on the electromechanical responses around a nano-sized elliptical piezoelectric inclusion embedded in an infinite piezoelectric matrix under far-field loading with an arbitrary angle, and the effect of loading angle is considered Combining the conformal mapping technique and electro-elastic surface/interface theory, a closed form solution of this problem is obtained and the interactive effect between the surface/interface and the aspect ratio of the elliptical inclusion is examined. More >

Raveendranath U. Nair, Preethi D.S, R. M. Jha

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 131-144, 2014, DOI:10.3970/cmc.2014.040.131

Abstract Controllable artificial dielectrics are used in the design of radomes to enhance their electromagnetic (EM) performance. The fabrication of such radome wall structures with controllable dielectric parameters seems to be an arduous task. Further even minor fluctuations of dielectric properties of radome wall due to fabrication uncertainties tend to result in drastic degradation of radome performance parameters. In the present work, a novel inhomogeneous radome with graded variation of dielectric parameters is proposed which limits the constraints on fabrication and facilitates excellent EM performance characteristics. This radome wall consists of five dielectric layers cascaded such that the middle layer has… More >

Trenton M. Ricks¹, Thomas E. Lacy, Jr.^1,2, Brett A. Bednarcyk³, Steven M.Arnold³, John W. Hutchins¹

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 99-130, 2014, DOI:10.3970/cmc.2014.040.099

Abstract A multiscale modeling methodology was developed for continuous fiber composites that incorporates a statistical distribution of fiber strengths into coupled multiscale micromechanics/ finite element (FE) analyses. A modified twoparameter Weibull cumulative distribution function, which accounts for the effect of fiber length on the probability of failure, was used to characterize the statistical distribution of fiber strengths. A parametric study using the NASA Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) was performed to assess the effect of variable fiber strengths on local composite failure within a repeating unit cell (RUC) and subsequent global failure. The NASA code FEAMAC… More >

Lianhua Ma¹, Qingsheng Yang²

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 79-98, 2014, DOI:10.3970/cmc.2014.040.079

Abstract Honeycombs are widely used in aerospace structures due to their low density and high specific strength. In this paper, effective electromagnetic properties of irregular honeycombs are investigated, by using the three dimensional homogenization theory and corresponding computational procedure. This homogenization method, being the extension of two-scale asymptotic approach, is employed to determine the expressions of the effective dielectric permittivity, magnetic permeability and electrical conductivity. To verify and validate the proposed model and procedure, effective permittivities of a typical irregular honeycomb are studied and compared with those of semi-empirical formulae. Moreover, the effect of geometry of honeycomb's unit cell on effective… More >