Qifeng Fan¹, Yaping Zhang², Leiting Dong^1,3, Shu Li¹, Satya N. Atluri⁴

CMC-Computers, Materials & Continua, Vol.47, No.2, pp. 65-88, 2015, DOI:10.3970/cmc.2015.047.065

Abstract A very simple displacement-based hexahedral 32-node element (denoted as DPH32), with over-integration in the thickness direction, is developed in this paper for static and dynamic analyses of laminated composite plates and shells. In contrast to higher-order or layer-wise higher-order plate and shell theories which are widely popularized in the current literature, the proposed method does not develop specific theories of plates and shells with postulated kinematic assumptions, but simply uses the theory of 3-D solid mechanics and the widely-available solid elements. Over-integration is used to evaluate the element stiffness matrices of laminated structures with an arbitrary number of laminae, while… More >

N. Ma^1,2, K. Sato³, K. Takada⁴

CMC-Computers, Materials & Continua, Vol.46, No.3, pp. 195-219, 2015, DOI:10.3970/cmc.2015.046.195

Abstract The local mechanical behaviors of advanced high strength steels undergoing a very large strain from uniform plastic deformation to fracture were investigated with the aid of a measured displacement field and a measurement based FEM. As a measurement method, a digital image grid method (DIGM) was developed and the three-direction transient displacement field on uniaxial tensile test pieces was measured. Combining the measured transient displacement field with the finite element method, a measurement based FEM (M-FEM) was developed for the computation of distribution of the local strains, local stresses and ductile damage accumulation in a tensile test piece. Furthermore, the… More >

Yuvaraj P¹, A Ramachra Murthy², Nagesh R Iyer³, S.K. Sekar⁴, Pijush Samui⁵

CMC-Computers, Materials & Continua, Vol.41, No.3, pp. 193-214, 2014, DOI:10.3970/cmc.2014.041.193

Abstract This paper presents fracture mechanics based Artificial Neural Network (ANN) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (Gf), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). Failure load of the beam (Pmax) is also predicated by using ANN model. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack tip opening displacement have been outlined. Back-propagation training technique has been employed for updating… More >

L. N. McCartney¹

CMC-Computers, Materials & Continua, Vol.35, No.3, pp. 183-227, 2013, DOI:10.3970/cmc.2013.035.183

Abstract Analytical stress transfer models are described that enable estimates to be made of the stress and displacement fields that are associated with fibre fractures or matrix cracks in unidirectional fibre reinforced composites. The models represent a clear improvement on popular shear-lag based methodologies. The model takes account of thermal residual stresses, and is based on simplifying assumptions that the axial stress in the fibre is independent of the radial coordinate, and similarly for the matrix. A representation for both the stress and displacement fields is derived that satisfies exactly the equilibrium equations, the required interface continuity equations for displacement and… More >

Yi Xiao¹, Qing H. Qin¹

CMC-Computers, Materials & Continua, Vol.34, No.2, pp. 95-115, 2013, DOI:10.3970/cmc.2013.034.095

Abstract In this paper, we propose a new approach of optical full-field measurement for displacement calculation on the surface of a cellular solid. Cell boundary points are sampled as nodes in the analysis. To find the nodal values of displacements the nodes are to be mapped onto their corresponding points in the deformed cell boundary by shape based point matching. A thin plate spline based robust point matching (TPS-RPM) approach is used instead of correlation of intensity pattern between two regions in traditional displacement measurement methods. The proposed approach involves multiple-step image processing including cell region segmentation, cell region matching and… More >

S. N.V.R.K. Kurapati¹, Y. C. Lu¹, F. Yang²

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.020.001

Abstract The spherical indentation of elastic film /substrate structures is analyzed using the finite element method. The load-displacement curves of the film /substrate structures of various configurations are obtained and analyzed. A generalized power law relation is established, which can be used to analyze the load-displacement curve of elastic film /substrate systems under spherical indentations. The indentation load is dependent on the modulus ratio of the film to the substrate and film thickness. A semi-analytical expression for the power of the power law relation is also obtained as a function of the normalized film thickness and normalized film modulus, which can… More >

Chih-Ping Wu^1,2, Hao-Yuan Li²

CMC-Computers, Materials & Continua, Vol.19, No.2, pp. 155-198, 2010, DOI:10.3970/cmc.2010.019.155

Abstract The Reissner mixed variational theorem (RMVT)- and principle of virtual displacements (PVD)-based finite layer methods (FLMs) are developed for the quasi-three-dimensional (3D) free vibration analysis of simply-supported, multilayered composite and functionally graded material (FGM) plates. The material properties of the FGM layers are assumed to obey either an exponent-law exponentially varied with the thickness coordinate or the power-law distributions of the volume fractions of the constituents. In these formulations, the plate is divided into a number of finite layers, where the trigonometric functions and Lagrange polynomials are used to interpolate the in- and out-of-plane variations of the field variables of… More >

Dein Shaw^1,2, Chih-Ren Huang², Li-Cheng Huang²

CMC-Computers, Materials & Continua, Vol.11, No.3, pp. 229-242, 2009, DOI:10.3970/cmc.2009.011.229

Abstract In this study, a method for designing an in-plane, free-form, beam-type spring for use in a lower-limb orthosis was developed. A spring designed by this method follows a predefined relationship between loading and displacement. To facilitate the analysis of the spring, it was divided into several beam segments. The stiffness equations related to loading (including moment and force) and displacements (linear and rotation) of each beam segment were found to follow a modified (non-linear) Castigliano's second theorem (NCST) and were assembled by using the continuity of nodal points of neighbouring curve segments. Using the proposed method, a spring designer can… More >

E.J. Sapountzakis¹, V.G. Mokos²

CMC-Computers, Materials & Continua, Vol.10, No.1, pp. 1-40, 2009, DOI:10.3970/cmc.2009.010.001

Abstract In this paper the boundary element method is employed to develop a displacement solution for the general transverse shear loading problem of composite beams of arbitrary constant cross section. The composite beam (thin or thick walled) consists of materials in contact, each of which can surround a finite number of inclusions. The materials have different elasticity and shear moduli and are firmly bonded together. The analysis of the beam is accomplished with respect to a coordinate system that has its origin at the centroid of the cross section, while its axes are not necessarily the principal bending ones. The transverse… More >