Open Access
ARTICLE
S. Liu1, X. Liu2,3, Y. Yuan2, H. A. Mang4
CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.3, pp. 157-200, 2014, DOI:10.3970/cmes.2014.100.157
Abstract A nonlinear viscoelastic constitutive model for early age concrete is presented in this paper. In this model, time-dependent properties, such as the elastic modulus, and thermal and autogenous shrinkage deformations, are computed by a stochastic multi-scale method, in which three different scales are specified according to the requirement of separation of scales, and different scales are linked by means of the asymptotic expansion theory with the help of specific representative volume elements (RVE). Thus, a cross-scale research from the cement paste to the macro structure of concrete is realized, and performance-based optimization of cement-based materials becomes possible. The developed constitutive… More >
Open Access
ARTICLE
Da-Guang Zhang1,2, Hao-Miao Zhou1
CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.3, pp. 201-222, 2014, DOI:10.3970/cmes.2014.100.201
Abstract A model of FGM beams resting on nonlinear elastic foundations is put forward by physical neutral surface and high-order shear deformation theory. Material properties are assumed to be temperature dependent and von Kármán strain-displacement relationships are adopted. Nonlinear bending and thermal postbuckling are given by multi-term Ritz method, and influences played by different supported boundaries, thermal environmental conditions, different elastic foundations, and volume fraction index are discussed in detail. It is worth noting that the effect of nonlinear elastic foundation increases with increasing deflection. More >
Open Access
ARTICLE
Q.W. Yang1,2, S.G. Du1, C.F. Liang1, L.J. Yang1
CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.3, pp. 223-248, 2014, DOI:10.3970/cmes.2014.100.223
Abstract Although the model-independent damage localization algorithms have been extensively developed in recent years, the theoretical relationship between these damage indicators and the definition of damage is not clear. Moreover the existing damage localization methods are usually dependent on the boundary conditions and the type of structure. In view of this, the paper presents a universal model-independent algorithm for structural damage localization. To this end, the explicit relationship between the damage and damage-induced displacement variation is firstly clarified by using the well-known Sherman-Morrison and Woodbury formulas. A theorem is then presented for structural damage localization. According to the theorem, the universal… More >
Open Access
ARTICLE
T.A. Elgohary1,2, L. Dong3, J.L. Junkins2,4, S.N. Atluri1,4
CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.3, pp. 249-275, 2014, DOI:10.3970/cmes.2014.100.249
Abstract In this study, we consider Initial Value Problems (IVPs) for strongly nonlinear dynamical systems, and study numerical methods to analyze short as well as long-term responses. Dynamical systems characterized by a system of second-order nonlinear ordinary differential equations (ODEs) are recast into a system of nonlinear first order ODEs in mixed variables of positions as well as velocities. For each discrete-time interval Radial Basis Functions (RBFs) are assumed as trial functions for the mixed variables in the time domain. A simple collocation method is developed in the time-domain, with Legendre-Gauss-Lobatto nodes as RBF source points as well as collocation points.… More >