M.R. Akbari¹, J. Ghanbari^1,2

CMC-Computers, Materials & Continua, Vol.45, No.3, pp. 187-202, 2015, DOI:10.3970/cmc.2015.045.187

Abstract Exact analytical solution for functionally graded hollow discs under internal pressure, thermal load and rotation are provided in this paper. Material properties of discs, i.e. elastic modulus, density and thermal expansion coefficient are assumed to vary in radial direction. Two power functions are assumed for property dependency to study various types of functional grading of materials in the discs. Assuming small deformations, a differential equation is obtained and solved for the Airy stress function. The effects of various grading functions on the stress and deformation distribution are studied and an optimum value for the power is obtained. More >

D. Pandit¹, N. Thomas², Bhakti Patel¹, S.M. Srinivasan¹

CMC-Computers, Materials & Continua, Vol.45, No.2, pp. 127-144, 2015, DOI:10.3970/cmc.2015.045.127

Abstract In this paper, a class of problems involving space constrained loading on thin beams with large deflections is considered. The loading is such that, the locus of the force application point moves along an arbitrarily predefined path, fixed in space. Both linear elastic as well as elastic-perfectly plastic materials are considered. A simplification is realized using the moment-curvature relationship directly. The governing equation obtained is highly non-linear owing to inclusion of both material and geometric non-linearity. A general algorithm is described to solve the governing equation using an incremental formulation coupled with Runge Kutta 4^th order initial value explicit solver.… More >

M. Marin^1,2, A.M. Abd-Alla^3,4, D. Raducanu¹, S.M. Abo-Dahab^3,5

CMC-Computers, Materials & Continua, Vol.45, No.2, pp. 107-126, 2015, DOI:10.3970/cmc.2015.045.107

Abstract Our study is dedicated to mixed initial boundary value problem for porous micropolar bodies. We prove that the solution of this problem depends continuously on coefficients which couple the micropolar deformation equations with the equations that model the evolution of voids. The evaluation of this dependence is made by using an appropriate measure. More >

Qingsheng Yang^1,2, Shaochong Yang^1,3, Xiaohu Lin⁴

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 57-74, 2015, DOI:10.3970/cmc.2015.045.057

Abstract An equivalent continuum model of an isogrid structure is utilized to analyze the impact response of isogrid structures and stiffened structures. The parameters of the equivalent model are determined, and the comparison between the equivalent continuous structure and the real grid structure are examined to validate the reliability of the equivalent model. Then, the impact responses of stiffened cylindrical shells with and without an elliptical hole are investigated by using the equivalent model of grid structures. For a different location and geometry of the elliptical hole, the deformation and load-bearing capacity of the grid-stiffened cylindrical shells are studied. The numerical… More >

Neeraj Dubey¹, Geeta Agnihotri¹

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 39-56, 2015, DOI:10.3970/cmc.2015.045.039

Abstract In this paper, midrib of coconut palm leaves (MCL) was investigated for the purpose of development of natural fiber reinforced polymer matrix composites. A new natural fiber composite as MCL/polyester is developed by the hand lay-up method, and the material and mechanical properties of the fiber, matrix and composite materials were evaluated. The effect of fiber content on the tensile, flexural, impact, compressive strength and heat distortion temperature (HDT) was investigated. It was found that the MCL fiber had the maximum tensile strength, tensile modulus flexural strength, flexural modulus and Izod impact strength of 177.5MPa, 14.85GPa, 316.04MPa and 23.54GPa, 8.23KJ/m²… More >

Leiting Dong^1,2, Robert Haynes³, Satya N. Atluri²

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 1-16, 2015, DOI:10.3970/cmc.2015.045.001

Abstract In this study, we propose to approximate the a－n relation as well as the da/dn－∆K relation, in fatigue crack propagation, by using the Moving Least Squares (MLS) method. This simple approach can avoid the internal inconsistencies caused by the celebrated Paris’ power law approximation of the da/dn－∆K relation, as well as the error caused by a simple numerical differentiation of the noisy data for a－n measurements in standard fatigue tests. Efficient, accurate and automatic simulations of fatigue crack propagation can, in general, be realized by using the currently developed MLS law as the “fatigue engine” [da/dn versus ∆K], and using… More >

Zhicheng Ou¹, Xiaohu Yao¹, Xiaoqing Zhang^1,2, Xuejun Fan³

CMC-Computers, Materials & Continua, Vol.44, No.3, pp. 205-222, 2014, DOI:10.3970/cmc.2014.044.205

Abstract The buckling of a thin film on a compressible compliant substrate in large deformation is studied. A finite-deformation theory is developed to model the film and the substrate under different original strain-free configurations. The neo-Hookean constitutive relation is applied to describe the substrate. Through the perturbation analysis, the analytical solution for this highly nonlinear system is obtained. The buckling wave number, amplitude and critical condition are obtained. Comparing with the traditional linear model, the buckling amplitude decreases. The wave number increases and relates to the prestrain. With the increment of Poisson’s ratio of the substrate, the buckling wave number increases,… More >

G. Q. Xie^1,2, M. X. Chi¹

CMC-Computers, Materials & Continua, Vol.44, No.2, pp. 123-140, 2014, DOI:10.3970/cmc.2014.044.123

Abstract Dynamic response sensitivity of a simply supported functionally graded magneto-electro-elastic plates have been studied by combining analytical method with finite element method. The functionally graded material parameters are assumed to obey exponential law in the thickness direction. A series solution of double trigonometric function agreed with the simply supported boundary condition is adopted in the plane of the plate and finite element method is used across the thickness of the plate. The finite element model is established based on energy variational principle. The coupled electromagnetic dynamic characteristics of a simply supported functionally graded magneto- electro-elastic plate are decided by its… More >

Vishal Shreyans Shah¹, Henyl Rakesh Shah², Pijush Samui³, A. Ramachra Murthy⁴

CMC-Computers, Materials & Continua, Vol.44, No.2, pp. 73-84, 2014, DOI:10.3970/cmc.2014.044.073

Abstract This paper deals with the development of models for prediction of facture parameters, namely, fracture energy and ultimate load of high strength and ultra high strength concrete based on Minimax Probability Machine Regression (MPMR) and Extreme Learning Machine (ELM). MPMR is developed based on Minimax Probability Machine Classification (MPMC). ELM is the modified version of Single Hidden Layer Feed Foreword Network (SLFN). MPMR and ELM has been used as regression techniques. Mathematical models have been developed in the form of relation between several input variables such as beam dimensions, water cement ratio, compressive strength, split tensile strength, notch depth, and… More >

Weijie Li¹, Haiming Huang^1,2, Bangcheng Ai³, Ye Tian¹

CMC-Computers, Materials & Continua, Vol.43, No.3, pp. 175-196, 2014, DOI:10.3970/cmc.2014.043.175

Abstract Physical and mathematical models are the key to analyze thermal behavior of charring materials in the thermal protection system of reentry vehicles subjected to aerodynamic heating. To explore the thermal behavior of charring ablator, we developed and compared two models (pyrolysis interface model and pyrolysis layer model) with pyrolysis and surface recession. Taking AVCOAT composites as an example, its nonlinear thermal behavior, which are caused by temperature dependent thermal properties, moving interfaces and moving boundary, were simulated using the calculation codes written respectively on the basis of the pyrolysis layer model and the pyrolysis interface model. Numerical results indicate that… More >