A. Brasiliano¹, W.R. Souza², G.N. Doz³, J.L.V. Brito⁴

Structural Durability & Health Monitoring, Vol.4, No.2, pp. 53-66, 2008, DOI:10.3970/sdhm.2008.004.053

Abstract It can be observed that usually, during structures useful life they are submitted to deterioration processes that, depending on the intensity, may affect their performance and load capacity and, as a result, their safety. In this case, it is necessary to accomplish an inspection in order to evaluate the conditions of the structure and to locate and quantify the intensity of the damage. Another important point is to study the behavior of brittle material beams with cracks, as an attempt of understanding the rupture mechanism and crack propagation phenomenon. In this paper, the Residual Error Method (Genovese, 2000) is applied… More >

Abdulnaser M. Alshoaibi^1,2, M. S. A. Hadi², A. K. Ariffin²

Structural Durability & Health Monitoring, Vol.3, No.1, pp. 15-28, 2007, DOI:10.3970/sdhm.2007.003.015

Abstract An adaptive finite element method is employed to analyze two-dimensional linear elastic fracture problems. The mesh is generated by the advancing front method and the norm stress error is taken as a posteriori error estimator for the h-type adaptive refinement. The stress intensity factors are estimated by a displacement extrapolation technique. The near crack tip displacements used are obtained from specific nodes of natural six-noded quarter-point elements which are generated around the crack tip defined by the user. The crack growth and its direction are determined by the calculated stress intensity factors as the maximum circumference theory is also been… More >

G. Dhondt¹

Structural Durability & Health Monitoring, Vol.1, No.1, pp. 21-34, 2005, DOI:10.3970/sdhm.2005.001.021

Abstract An algorithm is described which allows for the automatic calculation of crack propagation due to cyclic loading under mixed-mode conditions. The core of the procedure deals with the insertion of an arbitrarily formed crack into a virgin 20-node brick element mesh, thereby generating new quadratic bricks. One especially difficult aspect is the extension of the triangulation of the crack surface up to the boundary of the crack front elements. In the present article the technique is applied to linear elastic calculations using the stress intensity factor concept and a Paris-type law. However, other crack propagation parameters and crack propagation laws… More >

A.Y.Chen, J. Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 45-46, 2011, DOI:10.3970/icces.2011.020.045

Abstract The structural reliability of many brittle materials such as nanomaterials relies on the occurrence of intergranular, as opposed to transgranular, fracture in order to induce toughening by crack bridging. The current work examines the role of interface strength and grain size distribution in promoting intergranular fracture in order to maintain high toughening. A layered nanostructural 304SS sheet characterized by periodic distribution of nanocrystalline layers and micron-grained layers with graded grain size evolution has exhibited exceptional properties. The in situ SEM observations illustrate that an intergranular path and the consequent interface bridging process can be partitioned into five distinct regimes, namely:… More >

Ying Wang*, Zhen Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 176-176, 2019, DOI:10.32604/icces.2019.05665

Abstract Due to stress concentration as well as welding residual stress, fracture due to vehicle fatigue loads is easy to occur in the weld and its adjacent position of long-span bridge, especially at the toe of weld between the U-rib and orthotropic steel bridge deck. In order to investigate the fatigue crack propagation mechanism of the toe of weld in long-span bridge, a multi-scale finite element model including the whole bridge, local components, the welding details and cracks was established firstly. And then, based on birth and death element technology, the welding heat and structural coupling process simulation was carried out… More >

Kei Saito^1,*, Tei Hirashima¹, Ninshu Ma², Hidekazu Murakawa²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 174-174, 2019, DOI:10.32604/icces.2019.05406

Abstract Characteristic tensor is a tensor which is derived from the characteristic stress field near to a crack tip and is strongly related to fracture mechanics parameters in principle. Each component of characteristic tensor consists of an invariant quantity which defines intensity of stress singularity, corresponding to the stress component. Since it contains the information about not only intensity but also direction of the singularity, characteristic tensor can be a possible candidate which evaluates characteristics of cracking and its propagation direction under various complex loading conditions we have to assume for the practical analysis. Though parameters based on fracture mechanics have… More >

X.-H. Chen¹, Y.-W. Mai²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.2, pp. 43-50, 2010, DOI:10.3970/icces.2010.014.043

Abstract A general elastoplastic fracture mechanics theory is proposed for applying the Essential-Work-of-Fracture (EWF) Method to quasi-static and impact toughness characterization. Advanced finite element modeling is developed to simulate the EWF Method using the crack-tip opening angle criterion (CTOA) and the constitutive relation of the material under consideration. For Poly(ethylene-terephlate) (PET) films, the load-displacement curves are calculated for the whole crack propagation process of deeply double-edge notched tensile specimens (DENT) with different ligament lengths so as to determine the total work, the essential work and the non-essential work of fracture. The effects of specimen gauge length and ligament length on crack… More >

Weiming Tao¹, Xingwang Yang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.3, pp. 83-84, 2009, DOI:10.3970/icces.2009.012.083

Abstract Laser controlled separation of brittle materials like glass is a promising non-conven\discretionary {-}{}{}tional cutting method. It is an application of the crack propagation driven by thermal stresses induced by laser irradiation. In order to induce and control a crack propagating accurately along predetermined asymmetric trajectory in a brittle plate, an iterative method for effective laser scanning path was presented, and the effect of control parameters on the convergence was investigated. The iterative formulation for laser scanning path was based on PID control theory, which was composed of deviation of the crack from predetermined trajectory and its integral and differential. To… More >

Hsien-Chie Cheng¹, Yu-Chen Hsu², Wen-Hwa Chen²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 73-74, 2009, DOI:10.3970/icces.2009.012.073

Abstract Due to the limitation of fabrication technologies nowadays, initial defects in carbon nanotubes (CNTs) are inevitably perceived particularly during the manufacturing process or chemical treatment. The investigation of the effects of initial defects existing in CNTs on their mechanical properties and fracture behaviors becomes essential for their potentiality in engineering applications.
In this study, the defect effects, including number in percentage, type, and location, are explored using the molecular dynamics (MD) simulation with Tersoff Brenner potential. Results show that the mechanical properties, such as the elastic modulus, failure strength and strain, are strongly affected by the defects. Moreover, the distribution… More >

Dongwoo Sohn¹, Jae Hyuk Lim², Young-Sam Cho³, Seyoung Im¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 53-54, 2009, DOI:10.3970/icces.2009.010.053

Abstract A novel multiscale finite element (FE) scheme is proposed for a simulation of crack propagation in the heterogeneous media including randomly distributed microstructures, such as voids, rigid fibers. A fine scale mesh is employed to capture the singularity of the crack tip and the effect of microstructures at the vicinity of crack tip. On the other hand, a region far from the crack tip is composed of coarse scale mesh, wherein the effect of the microstructures is averaged through the homogenization theory. An interface between the fine scale mesh and the coarse scale mesh is connected by variable-node finite elements… More >