A. Ramachandra Murthy¹, Nagesh R. Iyer¹, B.K. Raghu Prasad²

CMC-Computers, Materials & Continua, Vol.30, No.2, pp. 177-194, 2012, DOI:10.3970/cmc.2012.030.177

Abstract This paper presents the details of nonlinear finite element analysis (FEA) of three point bending specimens made up of high strength concrete (HSC, HSC1) and ultra high strength concrete (UHSC). Brief details about characterization and experimentation of HSC, HSC1 and UHSC have been provided. Cracking strength criterion has been used for simulation of crack propagation by conducting nonlinear FEA. The description about FEA using crack strength criterion has been outlined. Bi-linear tension softening relation has been used for modeling the cohesive stresses ahead of the crack tip. Numerical studies have been carried out on fracture More >

Zhanqi Cheng¹, Zhenyu Wang¹, Zhongtao Luo^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 509-527, 2019, DOI:10.31614/cmes.2019.04339

Abstract In this work, a bond-based peridynamics (PD) model was built to analyze the dynamic fracture of shale material. Both the the convergence studies and the result of dynamic crack propagation were presented. As well-known, crack propagation, aggregation, and bifurcation play an critical role in the failure analysis of brittle materials such as shale. The dynamic crack propagation and branching analysis of shale by using the PD method were discussed. Firstly, the valid and accuracy of the PD model for the rock materials was verified by comparing with the existed numerical results. Secondly, we discussed the More >

Y. J. Guo¹, J. A. Nairn²

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.3, pp. 141-156, 2006, DOI:10.3970/cmes.2006.016.141

Abstract This paper describes algorithms for three-dimensional dynamic stress and fracture analysis using the material point method (MPM). By allowing dual velocity fields at background grid nodes, the method provides exact numerical implementation of explicit cracks in a predominantly meshless method. Crack contact schemes were included for automatically preventing crack surfaces from interpenetration. Crack-tip parameters, dynamic$J$-integral vector and mode I, II, and III stress intensity factors, were calculated from the dynamic stress solution. Comparisons to finite difference method (FDM), finite element method (FEM), and boundary element method (BEM), as well as to static theories showed that More >

N. Vu-Bac¹, H. Nguyen-Xuan², L. Chen³, S. Bordas⁴, P. Kerfriden⁴, R.N. Simpson⁴, G.R. Liu⁵, T. Rabczuk¹

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.4, pp. 331-356, 2011, DOI:10.3970/cmes.2011.073.331

Abstract This paper aims to incorporate the node-based smoothed finite element method (NS-FEM) into the extended finite element method (XFEM) to form a novel numerical method (NS-XFEM) for analyzing fracture problems of 2D elasticity. NS-FEM uses the strain smoothing technique over the smoothing domains associated with nodes to compute the system stiffness matrix, which leads to the line integrations using directly the shape function values along the boundaries of the smoothing domains. As a result, we avoid integration of the stress singularity at the crack tip. It is not necessary to divide elements cut by cracks More >

Letícia Fleck Fadel Miguel¹, Ignacio Iturrioz², Jorge Daniel Riera³

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.1, pp. 1-16, 2010, DOI:10.3970/cmes.2010.056.001

Abstract Numerical predictions of the failure load of large structures, accounting for size effects, require the adoption of appropriate constitutive relations. These relations depend on the size of the elements and on the correlation lengths of the random fields that describe material properties. The authors proposed earlier expressions for the tensile stress-strain relation of concrete, whose parameters are related to standard properties of the material, such as Young's modulus or specific fracture energy and to size. Simulations conducted for a typical concrete showed that as size increases, the effective stress-strain diagram becomes increasingly linear, with a… More >

W. J. Feng¹, X. Han², Y.S. Li³

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.1, pp. 1-26, 2009, DOI:10.3970/cmes.2009.048.001

Abstract The two-dimensional (2D) fracture problem of nonhomogeneous mag -neto-electro-thermo-elastic materials under dynamically thermal loading is investigated by the meshless local Petrov-Galerkin (MLPG) method. The material parameters are assumed to vary in either the height or width direction of the plates. The Laplace-transform technique is utilized to solve the time-dependent problems. In this MLPG analysis, the moving least squares (MLS) method is adopted to approximate the physical quantities, and the Heaviside step function is taken as a test function. The validity and efficiency of the MLPG method are firstly examined. The crack problem of a nonhomogeneous More >

A. Rama Ch,ra Murthy^1,2, G.S. Palani¹, Nagesh R. Iyer^1,3, M Srinivasa Pavan¹, Smitha Gopinath¹

CMC-Computers, Materials & Continua, Vol.19, No.2, pp. 135-154, 2010, DOI:10.3970/cmc.2010.019.135

Abstract This paper presents methodologies for fracture analysis of concrete structural components with and without considering tension softening effect. Stress intensity factor (SIF) is computed by using analytical approach and finite element analysis. In the analytical approach, SIF accounting for tension softening effect has been obtained as the difference of SIF obtained using linear elastic fracture mechanics (LEFM) principles and SIF due to closing pressure. Superposition principle has been used by accounting for non-linearity in incremental form. SIF due to crack closing force applied on the effective crack face inside the process zone has been computed… More >