The Experts below are selected from a list of 12864 Experts worldwide ranked by ideXlab platform
Filippo Cagnetti - One of the best experts on this subject based on the ideXlab platform.
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a vanishing viscosity approach to fracture growth in a cohesive zone model with prescribed Crack Path
Mathematical Models and Methods in Applied Sciences, 2008Co-Authors: Filippo CagnettiAbstract:The existence of Crack evolutions based on critical points of the energy functional is proved, in the case of a cohesive zone model with prescribed Crack Path. It turns out that evolutions of this type satisfy a maximum stress criterion for the Crack initiation. With an explicit example, it is shown that evolutions based on the absolute minimization of the energy functional do not enjoy this property.
Jean-michel Bergheau - One of the best experts on this subject based on the ideXlab platform.
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XFEM investigation of a Crack Path in residual stresses resulting from quenching
Finite Elements in Analysis and Design, 2013Co-Authors: Eric Feulvarch, Mickael Fontaine, Jean-michel BergheauAbstract:The aim of this work is the numerical study of a Crack Path in a residual stress field resulting from a manufacturing process such as quenching. An XFEM technique is proposed to that end and the example illustrating the quenching of a large thick plate is considered so as to demonstrate the capability of the method proposed. Indeed, during the quenching of steels, metallurgical transformations can occur, leading to high residual stresses at room temperature. From the practical point of view, the thick plate must be sawn after quenching. But it is experimentally observed that, under certain quenching conditions, the Crack initiated by the sawing, suddenly propagates through the thickness of the plate and then rotates through an angle of about 90^o. The numerical simulation of quenching is detailed and the results obtained under two operating conditions are given. Then the XFEM technique applied to the Crack propagation in a residual stress field is presented and the Cracking Path obtained on the quenched plate is compared to that obtained using the FEM coupled with a remeshing technique. It is shown that the computed Crack Path justifies experimental observations.
Yoshikazu Nakai - One of the best experts on this subject based on the ideXlab platform.
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evaluation of rolling contact fatigue Crack Path in high strength steel with artificial defects
International Journal of Fatigue, 2014Co-Authors: Taizo Makino, Yutaka Neishi, Daiki Shiozawa, Y Fukuda, Kentaro Kajiwara, Yoshikazu NakaiAbstract:Abstract The objectives of the present paper are to clarify the rolling contact fatigue (RCF) Crack Path in high strength steel with artificial defects using synchrotron radiation micro-computed tomography (SR micro CT) imaging and to discuss the mechanism of RCF Crack propagation by finite element (FE) analysis. Two Crack types, a vertical Crack and a horizontal Crack, were observed around the artificial defect by SR micro CT. The stress intensity factor (SIF) of horizontal Cracks, calculated by FE analysis, increased by the existence of vertical Cracks. The interaction between these two Crack types dominates RCF Crack propagation originating from artificial defects.
Eric Feulvarch - One of the best experts on this subject based on the ideXlab platform.
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XFEM investigation of a Crack Path in residual stresses resulting from quenching
Finite Elements in Analysis and Design, 2013Co-Authors: Eric Feulvarch, Mickael Fontaine, Jean-michel BergheauAbstract:The aim of this work is the numerical study of a Crack Path in a residual stress field resulting from a manufacturing process such as quenching. An XFEM technique is proposed to that end and the example illustrating the quenching of a large thick plate is considered so as to demonstrate the capability of the method proposed. Indeed, during the quenching of steels, metallurgical transformations can occur, leading to high residual stresses at room temperature. From the practical point of view, the thick plate must be sawn after quenching. But it is experimentally observed that, under certain quenching conditions, the Crack initiated by the sawing, suddenly propagates through the thickness of the plate and then rotates through an angle of about 90^o. The numerical simulation of quenching is detailed and the results obtained under two operating conditions are given. Then the XFEM technique applied to the Crack propagation in a residual stress field is presented and the Cracking Path obtained on the quenched plate is compared to that obtained using the FEM coupled with a remeshing technique. It is shown that the computed Crack Path justifies experimental observations.
Hynek Hadraba - One of the best experts on this subject based on the ideXlab platform.
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Effect of residual stresses to the Crack Path in alumina/zirconia laminates
Journal of the European Ceramic Society, 2020Co-Authors: Zdeněk Chlup, Lenka Novotná, Filip Siska, Daniel Drdlik, Hynek HadrabaAbstract:Abstract Laminates with alternating layers are well known from nature. The strongly bonded alumina/zirconia (Al2O3/ZrO2) layers can combine high fracture resistance with high strength and stiffness when properly tailored. The presence of compressive residual stresses formed in Al2O3 layers can suppress and deflect Cracks propagating through the layers. The Crack Path is governed by both the elastic properties and the internal stress field of individual layers. The laminates with various layer-thickness ratios ranging from 0.1 to 3 were used to investigate the effect of residual stresses and influence of Crack formation pattern on the Crack Path development. The indentation surface Cracks observed in various alumina-zirconia laminates exhibit the same Crack deflection independently on the level of internal stresses. The Crack deflection observed on the fracture surfaces of bending specimens was related to the indentations Cracks. The complicated Crack Path was explained experimentally by 3D reconstruction with the support of numerical simulations.