S. Liu¹, X. Liu^2,3, Y. Yuan², P. F. He¹, H. A. Mang^2,4

CMC-Computers, Materials & Continua, Vol.39, No.2, pp. 85-112, 2014, DOI:10.3970/cmc.2014.039.085

Abstract Autogenous shrinkage is defined as the bulk deformation of a closed, isothermal, cement-based material system, which is not subjected to external forces. It is associated with the hydration process of the cement paste. From the viewpoint of engineering practice, autogenous shrinkage deformations result in an increase of tensile stresses, which may lead to cracking of early-age concrete. Since concrete is a multi-phase composite with different material compositions and microscopic configurations at different scales, autogenous shrinkage does not only depend on the hydration of the cement paste, but also on the mechanical properties of the constituents and of their distribution. In… More >

V. Filonova¹, Y. Liu¹, M. Bailakanavar¹, J. Fish¹, Z. Yuan²

CMC-Computers, Materials & Continua, Vol.34, No.3, pp. 177-198, 2013, DOI:10.3970/cmc.2013.034.177

Abstract A corotational formulation for reduced order homogenization is presented. While in principle the proposed method is valid for problems with arbitrary large strains, it is computational advantageous over the classical direct computational homogenization method for large rotations but moderate unit cell distortions. We validate the method for several large deformation problems including: (i) hat-section composite beam with two-dimensional chopped tow composite architecture, (ii) polyethylene microstructure consisting of 'hard' and 'soft' domains (segments), and (iii) fiber framework called fiberform either embedded or not in an amorphous matrix. 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 >

Cheng-Te Chi¹, Ming-Hsiao Lee², Wen-Hwa Chen^1,3

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 239-256, 2011, DOI:10.3970/cmc.2011.024.239

Abstract A novel three-dimensional adaptive element-free Galerkin method (EFGM) based on a uniform background grid is proposed to cope with the problems with extremely large deformation. On the basis of this uniform background grid, an interior adaptive strategy through an error estimation within the analysis domain is developed. By this interior adaptive scheme, additional adaptive nodes are inserted in those regions where the solution accuracy needs to be improved. As opposed to the fixed uniform background grid, these inserted nodes can move along with deformation to describe the particular local deformation of the structure. In addition, a triangular surface technique is… More >

V.G.Yakhno¹

CMC-Computers, Materials & Continua, Vol.21, No.1, pp. 1-16, 2011, DOI:10.3970/cmc.2011.021.001

Abstract Homogeneous non-dispersive anisotropic materials, characterized by a positive constant permeability and a symmetric positive definite conductivity tensor, are considered in the paper. In these anisotropic materials, the electric and magnetic dyadic Green's functions are defined as electric and magnetic fields arising from impulsive current dipoles and satisfying the time-dependent Maxwell's equations in quasi-static approximation. A new method of deriving these dyadic Green's functions is suggested in the paper. This method consists of several steps: equations for electric and magnetic dyadic Green's functions are written in terms of the Fourier modes; explicit formulae for the Fourier modes of dyadic Green's functions… More >

N.J. Bartle¹, P.D. Gosling¹

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 19-62, 2010, DOI:10.3970/cmc.2010.020.019

Abstract ETFE cushions are increasingly being used to form high-profile facades and structural forms. This investigation aims to extend an analytical theory of large deformation in order to predict the shape and stress distributions of an un-patterned square ETFE cushion without the need to resort to discretised numerical methods. In order to assess the validity of the theoretical procedure a prototype cushion has been analysed using a finite element simulation. The theoretical procedure is also compared with alternative approximate equations proposed for the design of ETFE cushions. More >

M. Demiral, A. Roy, V. V. Silberschmidt¹

CMC-Computers, Materials & Continua, Vol.19, No.2, pp. 199-216, 2010, DOI:10.3970/cmc.2010.019.199

Abstract Static indentation experiments are typically performed to characterize the mechanical properties of a material of interest by a rigid indenter of known geometry to various depths. In contrast, dynamic indentation of materials has not been fully studied. Evaluating material performance under dynamic loading conditions is a challenge and we demonstrate that various modelling schemes may be appropriate for different flavours of dynamic indentation. In order to compare underlying thermo-mechanics and deformation processes in a static and dynamic indentation process, indentation of a rigid indenter into a workpiece to a fixed chosen penetration is extensively studied. A nonlinear strain rate and… More >

E.J. Sapountzakis¹, J.A. Dourakopoulos¹

CMC-Computers, Materials & Continua, Vol.18, No.2, pp. 121-154, 2010, DOI:10.3970/cmc.2010.018.121

Abstract In this paper a boundary element method is developed for the nonlinear flexural - torsional analysis of Timoshenko beam-columns of arbitrary simply or multiply connected constant cross section, undergoing moderate large deflections under general boundary conditions. The beam-column is subjected to the combined action of an arbitrarily distributed or concentrated axial and transverse loading as well as to bending and twisting moments. To account for shear deformations, the concept of shear deformation coefficients is used. Seven boundary value problems are formulated with respect to the transverse displacements, to the axial displacement, to the angle of twist (which is assumed to… More >

Qunfeng Liu¹, gping Shen²

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 59-76, 2010, DOI:10.3970/cmc.2010.017.059

Abstract Molecular Dynamics (MD) simulations have been performed using the EAM potential to investigate the deformation behaviors and mechanical properties of <100>/{100} gold nanowires with square cross-section at a certain strain rate under different temperatures ranging from 10 K to 700 K. It is found that <100>/{100} gold nanowires at high temperatures tend to form the extended stable nanobridges-Helical Multi-shell Structure (HMS), which is similar to the deformation behavior of <110> gold nanowires at room temperature reported in the previous experimental observations and simulations. The effect of temperature on the mechanical properties and deformation behaviors of gold nanowires was analyzed. The… More >

M.R. Khoshravan¹ and M.A. Setoodeh¹

CMC-Computers, Materials & Continua, Vol.16, No.3, pp. 195-228, 2010, DOI:10.3970/cmc.2010.016.195

Abstract The use of welding to permanently join plates is common in industry due to its high efficiency. But welding creates thermal stresses, which can lead to residual stresses and physical distortion. This phenomenon directly influences the buckling stiffness of the welded structure. The welding distortion not only makes difficult the erection of the project, but also influences the final quality and cost of production. In this research, the thermo-elastic-plastic conditions were simulated by a three-dimensional (3D) finite element model (FE). Mechanical and thermal properties of the material were applied to the model, leading to eigenvalue analysis of the thermal and… More >