S. Nishida¹, N. Hattori¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.3, pp. 179-186, 2007, DOI:10.3970/icces.2007.004.179

Abstract The authors have experimentally confirmed that the non-propagating microcracks are observed in the low carbon plain specimens subjected to the stress of fatigue limit by 1×107 cycles and not observed in those of pure copper and aluminum alloys etc.. In addition, there exists clear fatigue limit in typical austenitic stainless steel SUS304 but not exist the non-propagating micro-cracks subjected to the stress of fatigue limit by 1×107 cycles. On the other hand, there exist not only clear fatigue limit but also non-propagating micro-cracks in the high manganese austenitic steel (HMA 0.20%C steel). Then, the authors have focused to the existence… More >

H.K. Lee¹, J.W. Ju²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 123-128, 2007, DOI:10.3970/icces.2007.004.123

Abstract This paper summarizes the results of an analytical study (Lee and Ju, 2006) conducted to develop an approximate micromechanical analytical formulation to accommodate all the possible second-order, ensemble-volume averaged perturbations due to the interactions of randomly located microcracks and inclusions in brittle composites. To account for the three-dimensional effects of interactions among constituents, an approximate solution of a micromechanical framework considering the pairwise microcrack interactions, the pairwise inclusion interactions and the interactions between microcracks and inclusions have been systematically presented. The proposed pairwise interacting micromechanical damage models are compared to illustrate the influence of constituent interactions on effective elastic-damage moduli… More >

J. Bernal¹, S. Kanaun², V. Romero¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.4, pp. 189-194, 2007, DOI:10.3970/icces.2007.003.189

Abstract A new numerical method for the solution of integral equations of the theory of elasticity for bodies with cracks is developed. The method is based on a class of Gaussian approximating functions that simplify essentially the construction of the final matrix of the linear algebraic system of the discretized problem. The results of the application of the method to some plane problems of elasticity were compared with the exact solutions and some other numerical solutions that exist in literature. More >

A. Tadeu¹, L. Godinho¹, J. António¹, P. Amado Mendes¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.3, pp. 163-168, 2007, DOI:10.3970/icces.2007.003.163

Abstract This paper evaluates the 3D wave propagation in an elastic slab containing cracks whose geometry does not change along the direction parallel to the formation surfaces. Two different formulations are used and compared: the Traction Boundary Element Method (TBEM) and the Method of Fundamental Solutions (MFS). Both approaches are developed in the frequency domain and surmount the thin-body difficulty posed by the classical Boundary Element Method (BEM). The TBEM models the crack as a single line. The resulting hypersingular integrals are evaluated analytically. For the MFS, the solution is approximated in terms of a linear combination of fundamental solutions, generated… More >

Qingjia Chi*, Xinge Geng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.1, pp. 118-118, 2019, DOI:10.32604/icces.2019.05168

Abstract The binding of DNA to protein in the cellular nucleus is a common phenomenon. DNA molecules will soften at the binding region when they adhere to proteins. Softening will affect the mechanical properties significantly. However, the mechanism underlying the mechanical softening remains to be explored. To understand the changes in the mechanical properties of DNA, the peridynamics technique can effectively capture the stress of the softened DNA under tensile forces. And later the results were verified by finite element computations. Utilizing the computations of perydynamics to reveal the stretch of the double-stranded DNA. The results demonstrated DNA was easy to… More >

J. Scheel^∗, A. Ricoeur

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 9-9, 2019, DOI:10.32604/icces.2019.05030

Abstract The heterogeneous state of stress in composite materials and the possible damage in interfaces, lead to a complicated problem concerning matrix crack tip loading analysis and crack path prediction. A powerful and accurate tool for calculating crack tip loadings is the J-integral, which was independently introduced by Rice and Cherepanov. The calculation of crack deflection angles using the J-integral criterion is enabled by the J-integral vector formulation, whereupon the calculation of matrix crack tip loadings and also interface crack tip loadings is possible. The J-integral and the crack tip opening displacement, as crack tip loading quantity of cohesive zone models,… More >

Masanori Kikuchi¹, Yoshitaka Wada², Hitomi Suyama³, YuLong Li⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 222-224, 2009, DOI:10.3970/icces.2009.009.222

Abstract Prediction of fatigue crack growth in mechanical component is one of the most important problems to prevent catastrophic fracture accident. FEM is generally used for this purpose, but as crack shape changes during growing process, it is necessary to re-mesh for new crack shape. It is time consuming and is very difficult especially for 3-d. problem.
In this study, S-version FEM^[1][2] is employed to solve this problem, and fully automatic crack growth simulation system is made by combining with automatic mesh generationsystem. In the 3-d. field, crack tip stressconditionbecomes under mixed mode condition, and three stress intensity factor, K_I,K_II and… More >

E. Schnack¹, A. Dimitrov², F.-G. Buchholz³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.4, pp. 139-146, 2007, DOI:10.3970/icces.2007.001.139

Abstract In fracture mechanics, we have to discuss corner and edge singularities for two- and three-dimensional problems in isotropic and layered anisotropic continua. To say something about the behavior of crack propagation starting from corners and edges, we need the information about stress asymptotics in the vicinity of three-dimensional corner points. Thus, in this paper we can study two aspects: the interface crack in layered unisotropic materials with re-entrant corners and surface cracks for the homogeneous isotropic continua. To study the effect of geometrical singularities on the stress intensity factors, we have to define generalized stress intensity factors. We are starting… More >

B.K. Raghu Prasad¹, Renuka Devi M.V.²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 55-60, 2007, DOI:10.3970/icces.2007.001.055

Abstract The concepts associated with concrete crack formation and propagation is discussed in the light of fractal and probability theories. These concepts are employed to model the tortuous crack path in a highly heterogeneous medium of concrete. Fictitious Crack Model (FCM)[1] is extended to analyze plain concrete beams with such tortuous cracks. The parametric study has been carried out in order to obtain the influence of various fracture parameters on the beam response. More >

De Xie¹, Anthony M. Waas^1,2, Khaled W. Shahwan³, Jessica A. Schroeder⁴, Raymond G. Boeman⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.6, pp. 515-524, 2004, DOI:10.3970/cmes.2004.006.515

Abstract A numerical method based on the virtual crack closure technique (VCCT) [Rybicki and Kanninen (1977)] and in conjunction with the finite element (FE) method is presented to compute strain energy release rates for cracks that kink. The method partitions the strain energy release rate and provides an efficient means to compute values of the mode I (G_I) and mode II (G_II) energy release rate at the tip of a kinking crack. The solution procedure is shown to be computationally efficient and operationally simple, involving only the nodal forces and displacements near the crack tip. Example problems with kinking cracks in… More >