The Experts below are selected from a list of 6459 Experts worldwide ranked by ideXlab platform
Liang Wang - One of the best experts on this subject based on the ideXlab platform.
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micromechanics based progressive failure analysis of carbon fiber epoxy composite vessel under combined internal pressure and thermomechanical loading
Composites Part B-engineering, 2016Co-Authors: Chuanxiang Zheng, Liang Wang, Shuang Wei, Zongxi WeiAbstract:Abstract A progressive failure analysis algorithm based on micromechanics of failure (MMF) theory and material property degradation method (MPDM) is developed, wherein the MMF is used to predict the failure initiation at constituent level and the MPDM is employed to account for the post failure behavior of the Damaged materials. The progress of Damage is controlled by a linear Damage Evolution Law, which is based on the fracture energy dissipating during the process. This micromechanics-based approach is implemented by a user-material subroutine (UMAT) in ABAQUS, which is sufficiently general to predict the ultimate strength and complex failure behaviors of the composite vessel subject to both high pressure and thermal loading. In addition, the predictions of the model are also compared with those by experiment and traditional finite element analysis.
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continuum Damage modeling and progressive failure analysis of carbon fiber epoxy composite pressure vessel
Composite Structures, 2015Co-Authors: Liang Wang, Chuanxiang ZhengAbstract:Abstract This paper presents a progressive Damage model, which is sufficiently general to predict the ultimate load-bearing ability and complex failure behaviors of the aluminum–carbon fiber/epoxy composite vessel structure. The model is implemented in the commercial finite element software ABAQUS based on the integration of material property degradation method (MPDM) and cohesive element (CE) method. The MPDM is implemented by ABAQUS user subroutine UMAT to model the intralaminar failure of composite laminates, while CEs are employed to simulate the delamination initiation and Evolution at the interfaces. The progression of Damage is controlled by a linear Damage Evolution Law, which is based on the fracture energy dissipating during the process. In addition, the predictions of the model are also compared with experiments and reasonably good agreements are obtained.
Reza Hojjatitalemi - One of the best experts on this subject based on the ideXlab platform.
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prediction of fretting fatigue crack initiation in double lap bolted joint using continuum Damage mechanics
International Journal of Fatigue, 2015Co-Authors: A Ferjaoui, Tongyan Yue, Abdel M Wahab, Reza HojjatitalemiAbstract:Abstract In fretting fatigue, the combination of small oscillatory motion, normal pressure and cyclic axial loading develops a noticeable stress concentration at the contact zone leading to accumulation of Damage in fretted region, which produces micro cracks, and consequently forms a leading crack that can lead to failure. In fretting fatigue experiments, it is very difficult to detect the crack initiation phase. Damages and cracks are always hidden between the counterpart surfaces. Therefore, numerical modeling techniques for analyzing fretting fatigue crack initiation provide a precious tool to study this phenomenon. This article gives an insight in fretting fatigue crack initiation. This is done by means of an experimental set up and numerical models developed with the Finite Element Analysis (FEA) software package ABAQUS. Using Continuum Damage Mechanics (CDM) approach in conjunction with FEA, an uncoupled Damage Evolution Law is used to model fretting fatigue crack initiation lifetime of Double Bolted Lap Joint (DBLJ). The predicted fatigue lifetimes are in good agreement with the experimentally measured ones. This comparison provides insight to the contribution of Damage initiation and crack propagation in the total fatigue lifetime of DBLJ test specimens.
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fretting fatigue crack initiation lifetime predictor tool using Damage mechanics approach
Tribology International, 2013Co-Authors: Reza Hojjatitalemi, Magd Abdel WahabAbstract:Abstract Fretting fatigue is a combination of two complex mechanical phenomena. Fretting appears between components that are subjected to small relative oscillatory motions. Once these connected components undergo cyclic fatigue load, fretting fatigue occurs. In general, fretting fatigue failure process can be divided into two main portions, namely crack initiation and crack propagation. Fretting fatigue crack initiation characteristics are very difficult to detect because Damages such as micro-cracks are always hidden between two contact surfaces. In this paper Continuum Damage Mechanics (CDM) approach in conjunction with Finite Element Analyses (FEA) is used to find a predictor tool for fretting fatigue crack initiation lifetime. For this purpose an uncoupled Damage Evolution Law is developed to model fretting fatigue crack initiation lifetime at various fretting condition such as contact geometry, axial stress, normal load and tangential load. The predicted results are validated with published experimental data from literature.
Tomasz Wierzbicki - One of the best experts on this subject based on the ideXlab platform.
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prediction of plane strain fracture of ahss sheets with post initiation softening
International Journal of Solids and Structures, 2010Co-Authors: Tomasz WierzbickiAbstract:Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening Law and the incremental Damage Evolution Law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell elements and plane strain elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D plane strain element and shell element models.
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prediction of plane strain fracture of ahss sheets with post initiation softening
International Journal of Solids and Structures, 2010Co-Authors: Yaning Li, Tomasz WierzbickiAbstract:Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening Law and the incremental Damage Evolution Law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell elements and plane strain elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D plane strain element and shell element models.
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ductile fracture characterization of aluminum alloy 2024 t351 using Damage plasticity theory
International Journal of Applied Mechanics, 2009Co-Authors: Liang Xue, Tomasz WierzbickiAbstract:This paper presents the calibration procedure for aluminum alloy 2024-T351 using a recently developed Damage plasticity theory. The Damage plasticity theory consists of a full three dimensional Damage Evolution Law where the pressure sensitivity and the Lode angle dependence are included in a fracture envelope and the equivalent plastic strain is used as a time-like variable to determine the Damage rate. Because of the coupled nature of the plastic strain and the Damage, material parameters are calibrated from a parallel study of numerical simulations and experimental measurements. A set of 10 tests that cover a wide range stress states for both the hydrostatic pressure and the Lode angle are conducted in order to capture the fracture envelope in the interested stress range. The experimental setups include un-notched and notched round bars with three different notch radii, a doubly grooved flat plate and compressed cylinders of three different heights at two friction conditions. The detailed numerical and experimental procedure of calibration is demonstrated by using four of these tests. The accuracy of the calibrated material parameters is further assessed by the remainder of tests. Notch sensitivity in tensile round bars and the friction conditions in upsetting tests are discussed in detail. Good agreement in the tested load conditions is achieved for both the fracture patterns and the load-displacement curves.
Magd Abdel Wahab - One of the best experts on this subject based on the ideXlab platform.
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Numerical Estimation of Fretting Fatigue Lifetime Using Damage and Fracture Mechanics
Tribology Letters, 2013Co-Authors: Reza Hojjati-talemi, Eugenio Giner, Magd Abdel Wahab, Mohamad SabsabiAbstract:Fretting fatigue is a complex tribological phenomenon that can cause premature failure of connected components that have small relative oscillatory movement. The fraction of fretting fatigue lifetime spent in crack initiation and in crack propagation depends on many factors, e.g., contact stresses, amount of slip, frequency, environmental conditions, etc., and varies from one application to another. Therefore, both crack initiation and propagation phases are important in analysing fretting fatigue. In this investigation, a numerical approach is used to predict these two portions and estimate fretting fatigue failure lifetime under a conformal contact configuration. For this purpose, an uncoupled Damage Evolution Law based on principles of continuum Damage mechanics is developed for modelling crack initiation. The extended finite element method approach is used for calculating crack propagation lifetimes. The estimated results are validated with previously reported experimental data and compared with other available methods in the literature.
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fretting fatigue crack initiation lifetime predictor tool using Damage mechanics approach
Tribology International, 2013Co-Authors: Reza Hojjatitalemi, Magd Abdel WahabAbstract:Abstract Fretting fatigue is a combination of two complex mechanical phenomena. Fretting appears between components that are subjected to small relative oscillatory motions. Once these connected components undergo cyclic fatigue load, fretting fatigue occurs. In general, fretting fatigue failure process can be divided into two main portions, namely crack initiation and crack propagation. Fretting fatigue crack initiation characteristics are very difficult to detect because Damages such as micro-cracks are always hidden between two contact surfaces. In this paper Continuum Damage Mechanics (CDM) approach in conjunction with Finite Element Analyses (FEA) is used to find a predictor tool for fretting fatigue crack initiation lifetime. For this purpose an uncoupled Damage Evolution Law is developed to model fretting fatigue crack initiation lifetime at various fretting condition such as contact geometry, axial stress, normal load and tangential load. The predicted results are validated with published experimental data from literature.
Chuanxiang Zheng - One of the best experts on this subject based on the ideXlab platform.
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micromechanics based progressive failure analysis of carbon fiber epoxy composite vessel under combined internal pressure and thermomechanical loading
Composites Part B-engineering, 2016Co-Authors: Chuanxiang Zheng, Liang Wang, Shuang Wei, Zongxi WeiAbstract:Abstract A progressive failure analysis algorithm based on micromechanics of failure (MMF) theory and material property degradation method (MPDM) is developed, wherein the MMF is used to predict the failure initiation at constituent level and the MPDM is employed to account for the post failure behavior of the Damaged materials. The progress of Damage is controlled by a linear Damage Evolution Law, which is based on the fracture energy dissipating during the process. This micromechanics-based approach is implemented by a user-material subroutine (UMAT) in ABAQUS, which is sufficiently general to predict the ultimate strength and complex failure behaviors of the composite vessel subject to both high pressure and thermal loading. In addition, the predictions of the model are also compared with those by experiment and traditional finite element analysis.
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continuum Damage modeling and progressive failure analysis of carbon fiber epoxy composite pressure vessel
Composite Structures, 2015Co-Authors: Liang Wang, Chuanxiang ZhengAbstract:Abstract This paper presents a progressive Damage model, which is sufficiently general to predict the ultimate load-bearing ability and complex failure behaviors of the aluminum–carbon fiber/epoxy composite vessel structure. The model is implemented in the commercial finite element software ABAQUS based on the integration of material property degradation method (MPDM) and cohesive element (CE) method. The MPDM is implemented by ABAQUS user subroutine UMAT to model the intralaminar failure of composite laminates, while CEs are employed to simulate the delamination initiation and Evolution at the interfaces. The progression of Damage is controlled by a linear Damage Evolution Law, which is based on the fracture energy dissipating during the process. In addition, the predictions of the model are also compared with experiments and reasonably good agreements are obtained.
