M. C. Song¹, B.V. Sankar¹, G. Subhash¹, C. F. Yen²

CMC-Computers, Materials & Continua, Vol.35, No.1, pp. 67-85, 2013, DOI:10.3970/cmc.2013.035.067

Abstract Delamination initiation and propagation in plain woven laminates and 3D orthogonal woven composites during short beam shear (SBS) test were analyzed using finite element (FE) analyses. Two kinds of 3D woven composites, containing single z-yarns and double z-yarns, were considered. The FE models were guided by experimental observations from SBS tests for the same material systems. A series of mechanisms including creation and evolution of matrix cracks and delaminations were modeled discretely. The force-displacement curves obtained from the FE simulations were compared with those from experiments. Further parametric studies were conducted to investigate the effects of z-yarns and interlaminar fracture… More >

A. Ataş¹, C. Soutis²

CMC-Computers, Materials & Continua, Vol.34, No.3, pp. 199-226, 2013, DOI:10.3970/cmc.2013.034.199

Abstract A strength prediction method is presented for double-lap single fastener bolted joints of cross-ply carbon fibre reinforced plastic (CFRP) composite laminates using cohesive zone elements (CZEs). Three-dimensional finite element models were developed and CZEs were inserted into subcritical damage planes identified from X-ray radiographs. The method makes a compromise between the experimental correlation factors (dependant on lay-up, stacking sequence and joint geometry) and three material properties (fracture energy, interlaminar strength and nonlinear shear stress-strain response). Strength of the joints was determined from the predicted load-displacement curves considering sub-laminate and plylevel scaling effects. The predictions are in a reasonable agreement with… More >

F. Wang^1,2, D.M. Zhang^1,2,3, H.H. Zhu⁴, H.W. Huang^1,2, J.H. Yin⁵

CMC-Computers, Materials & Continua, Vol.34, No.1, pp. 63-81, 2013, DOI:10.3970/cmc.2013.034.063

Abstract This paper studies the impact of overhead excavation on an existing tunnel through both field monitoring and a full 3D numerical model. It is found that the excavation induced longitudinal heave of the tunnel is uneven with maximum heave occurring below the excavation center. Even at the same cross section, the excavation induced heave is not uniform with the most significant heave occurring at the tunnel crown. The bending moments of the tunnel lining is decreased due to the overhead excavation. The axial forces of the tunnel lining generally decrease except at the tunnel invert. The shear forces of the… More >

C. Wang¹, W. Gao¹, C.W. Yang¹, C.M. Song¹

CMC-Computers, Materials & Continua, Vol.25, No.1, pp. 19-46, 2011, DOI:10.3970/cmc.2011.025.019

Abstract The random interval response and probabilistic interval reliability of structures with a mixture of random and interval properties are studied in this paper. Structural stiffness matrix is a random interval matrix if some structural parameters and loads are modeled as random variables and the others are considered as interval variables. The perturbation-based stochastic finite element method and random interval moment method are employed to develop the expressions for the mean value and standard deviation of random interval structural displacement and stress responses. The lower bound and upper bound of the mean value and standard deviation of random interval structural responses… More >

L. Dong¹, S. N. Atluri²

CMC-Computers, Materials & Continua, Vol.24, No.1, pp. 61-104, 2011, DOI:10.3970/cmc.2011.024.061

Abstract A simple procedure to formulate efficient and stable hybrid/mixed finite elements is developed, for applications in macro- as well as micromechanics. In this method, the strain and displacement field are independently assumed. Instead of using two-field variational principles to enforce both equilibrium and compatibility conditions in a variational sense, the independently assumed element strains are related to the strains derived from the independently assumed element displacements, at a finite number of collocation points within the element. The element stiffness matrix is therefore derived, by simply using the principle of minimum potential energy. Taking the four-node plane isoparametric element as an… More >

M. Al-Ajmi¹, A. Benjeddou²

CMC-Computers, Materials & Continua, Vol.23, No.3, pp. 265-286, 2011, DOI:10.3970/cmc.2011.023.265

Abstract A new discrete layer finite element (DLFE) is presented for electro-mechanically coupled analyses of moderately thick piezoelectric adaptive composite plates. The retained kinematics is based on layer-wise first-order shear deformation theory, and considers the plies top and bottom surfaces in-plane displacements and the plate transverse deflection as mechanical unknowns. The former are assumed in-plane Lagrange linear, while the latter is assumed in-plane full (Lagrange) quadratic; this results in a nine nodes quadrangular (Q9) DLFE. The latter is validated in free-vibrations, first numerically against ANSYS three-dimensional piezoelectric finite elements for a cantilever moderately thick aluminum plate with two co-localized piezoceramic patches,… More >

Xiaonan Hou¹, Hong Hu¹, Yanping Liu¹, Vadim Silberschmidt²

CMC-Computers, Materials & Continua, Vol.23, No.2, pp. 119-134, 2011, DOI:10.3970/cmc.2011.023.119

Abstract Compressibility of warp-knitted spacer fabrics is one of their important mechanical properties with regard to many special applications such as body protection, cushion and mattresses. Due to specific structural features of the fabric and a non-linear mechanical behavior of monofilaments, the compression properties of this kind of fabrics are very complicated. Although several studies have been performed to investigate their compression behavior, its mechanism has not well been understood yet. This work is concerned with a study of compression mechanism of a selected warp-knitted spacer fabric with a given sandwich structure. Both experimental and numerical methods are used to study… More >

Yihua Xiao¹, Xu Han^1,2, Dean Hu¹

CMC-Computers, Materials & Continua, Vol.23, No.1, pp. 9-34, 2011, DOI:10.3970/cmc.2011.023.009

Abstract For impact computations, it is efficient to model small and large deformation regions by Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH), respectively. However, it requires an effective algorithm to couple FEM and SPH calculations. To fulfill this requirement, an alternative coupling algorithm is presented in this paper. In the algorithm, the coupling between element and particle regions are achieved by treating elements as imaginary particles and applying equivalent tractions to element sides on coupling interfaces. In addition, an adaptive coupling technique is proposed based on the algorithm to improve the computational efficiency of FEM-SPH coupling further. For this… More >

Smitha Gopinath^1,2, A. Ramach,ra Murthy¹, Nagesh R. Iyer¹

CMC-Computers, Materials & Continua, Vol.22, No.1, pp. 55-72, 2011, DOI:10.3970/cmc.2011.022.055

Abstract This paper presents the mathematical modeling techniques for nonlinear finite element analysis of RC structure to incorporate uniform corrosion effects. Effect of corrosion has been simulated as reduction in effective cross-sectional area of reinforcing bar, reduction in bonding phenomena and as reduction in material properties of reinforcing bar such as yield strength and elastic modulus. Appropriate constitutive laws for (i) corroded rebar elements and (ii) bond slip with corroded bar have been described. Procedure has been outlined to determine the global damage indicator by secant stiffness based approach. A corroded RC beam has been analysed to validate the proposed model… More >

Wenqing Wang¹, Thomas Schnicke², Olaf Kolditz³

CMC-Computers, Materials & Continua, Vol.21, No.3, pp. 217-236, 2011, DOI:10.3970/cmc.2011.021.217

Abstract This work focuses on parallel finite element simulation of thermal hydraulic and mechanical (THM) coupled processes in porous media, which is a common phenomenon in geological applications such as nuclear waste repository and CO2 storage facilities. The Galerkin finite element method is applied to solve the derived partial differential equations. To deal with the coupling terms among the equations, the momentum equation is solved individually in a monolithic manner, and moreover their solving processes are incorporated into the solving processes of nonisothermal hydraulic equation and heat transport equation in a staggered manner. The computation task arising from the present method… More >