The Experts below are selected from a list of 399 Experts worldwide ranked by ideXlab platform
Antonio Marques - One of the best experts on this subject based on the ideXlab platform.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part i constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation: Part I – Constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, Pedro P. Camanho, F.m. Andrade Pires, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part ii numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation: Part II – Numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, Pedro P. Camanho, F.m. Andrade Pires, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.
Sina Eskandari - One of the best experts on this subject based on the ideXlab platform.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part i constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation: Part I – Constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, Pedro P. Camanho, F.m. Andrade Pires, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part ii numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation: Part II – Numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, Pedro P. Camanho, F.m. Andrade Pires, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.
Stephen R Hallett - One of the best experts on this subject based on the ideXlab platform.
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interaction of inter and Intralaminar Damage in scaled quasi static indentation tests part 1 experiments
Composite Structures, 2016Co-Authors: Emmanuelle Abisset, Federica Daghia, Michael R Wisnom, Stephen R HallettAbstract:The evaluation of the predictive capabilities of models proposed in the literature for laminated composites calls for experimental testing providing detailed results of both the global and local response in terms of degradation mechanisms, such as delamination, transverse cracking and fibre breaking. Scaled tests, in which one or more characteristic dimensions are modified, allow variation of the different mechanisms. In this paper, a unique series of scaled indentation tests are performed on quasi-isotropic composite plates, and a detailed assessment of the Damage evolution is carried out through non-destructive techniques, including ultrasonic C-scan and X-ray Computed Tomography (CT). Four different configurations are tested, presenting changes in both in-plane dimensions and fully three dimensional scaled cases. The latter are performed with sublaminate and ply scaling to show the effect of ply thickness on response. A detailed set of results for both global behaviour and the Damage evolution is provided to demonstrate the mechanisms controlling behaviour and to create a reference set of data for model validation. The scaling effects observed are also discussed making use of simplified analytical models.
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Interaction of inter- and Intralaminar Damage in scaled quasi-static indentation tests: Part 1 – Experiments
Composite Structures, 2016Co-Authors: Emmanuelle Abisset, Federica Daghia, Michael R Wisnom, Stephen R HallettAbstract:The evaluation of the predictive capabilities of models proposed in the literature for laminated composites calls for experimental testing providing detailed results of both the global and local response in terms of degradation mechanisms, such as delamination, transverse cracking and fibre breaking. Scaled tests, in which one or more characteristic dimensions are modified, allow variation of the different mechanisms. In this paper, a unique series of scaled indentation tests are performed on quasi-isotropic composite plates, and a detailed assessment of the Damage evolution is carried out through non-destructive techniques, including ultrasonic C-scan and X-ray Computed Tomography (CT). Four different configurations are tested, presenting changes in both in-plane dimensions and fully three dimensional scaled cases. The latter are performed with sublaminate and ply scaling to show the effect of ply thickness on response. A detailed set of results for both global behaviour and the Damage evolution is provided to demonstrate the mechanisms controlling behaviour and to create a reference set of data for model validation. The scaling effects observed are also discussed making use of simplified analytical models.
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interaction of inter and Intralaminar Damage in scaled quasi static indentation tests part 2 numerical simulation
Composite Structures, 2016Co-Authors: Michael R Wisnom, Stephen R HallettAbstract:Abstract A numerical study, accompanied by the experimental data from Part 1 of this paper, provides a clear picture of the global Damage behaviour and local response of four scaled Carbon Fibre Reinforced Polymer (CFRP) laminates under quasi-static transverse loading. Interface elements with a cohesive formulation are employed to model delamination, matrix cracks and their interaction. The predictive Damage from different numerical simulations with different levels of detail is presented, and the validity is illustrated both qualitatively and quantitatively. Specifically the number of inserted potential Intralaminar crack paths is varied from no cracks, through single, then double, to multiple cracks. It is shown that the models with the capability to simulate multiple matrix cracks best predict the key aspects of barely visible Damage of composite laminate during quasi-static loading.
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Interaction of inter- and Intralaminar Damage in scaled quasi-static indentation tests: Part 2 – Numerical simulation
Composite Structures, 2016Co-Authors: Michael R Wisnom, Stephen R HallettAbstract:Abstract A numerical study, accompanied by the experimental data from Part 1 of this paper, provides a clear picture of the global Damage behaviour and local response of four scaled Carbon Fibre Reinforced Polymer (CFRP) laminates under quasi-static transverse loading. Interface elements with a cohesive formulation are employed to model delamination, matrix cracks and their interaction. The predictive Damage from different numerical simulations with different levels of detail is presented, and the validity is illustrated both qualitatively and quantitatively. Specifically the number of inserted potential Intralaminar crack paths is varied from no cracks, through single, then double, to multiple cracks. It is shown that the models with the capability to simulate multiple matrix cracks best predict the key aspects of barely visible Damage of composite laminate during quasi-static loading.
P P Camanho - One of the best experts on this subject based on the ideXlab platform.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part i constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part ii numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.
F Andrade M Pires - One of the best experts on this subject based on the ideXlab platform.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part i constitutive model
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract The nonlinear behavior of fiber-reinforced composite materials is investigated in the presence of both Damage evolution and fiber rotation. While Damage mechanisms usually decrease the stiffness of the material and cause premature failure, fiber rotation can lead to a stiffening of the material, due to the reorientation of the fiber towards the loading direction, and delay failure. In this paper, fiber rotation is modeled by an analytical solution and incorporated in Maimi Damage model. The predictions of the model with and without fiber rotation are analyzed and compared with the experimental results of IM7/8552 carbon–epoxy composite. The results show the importance of including fiber rotation in the constitutive equations and the accuracy of the overall model in predicting final failure of the specimens.
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Intralaminar Damage in polymer composites in the presence of finite fiber rotation part ii numerical analysis and validation
Composite Structures, 2016Co-Authors: Sina Eskandari, F Andrade M Pires, P P Camanho, Antonio MarquesAbstract:Abstract In this paper the effects of fiber rotation inclusion in the continuum Damage model are studied. Firstly, transverse compression case for unidirectional laminate composites is considered and the ability of the model to predict the final failure strength and fiber rotation angle for different initial fiber angles is analyzed using experimental data, and compared to the Damage model excluding fiber rotation. Some Damage analysis also carried out by means of X-ray images of Damaged specimens. In addition, the ability of the models to be used for failure analysis of the thermoplastic matrix composites is evaluated. This type of composites reveals high level of fiber rotation, that makes them a good candidate to be investigated under this context. The study suggests the importance of fiber rotation inclusion in the Damage analysis and highlights its advantages over not regarding it. Besides, it reveals the capability of the rotation considered model to be used for thermoplastic-based composites while the original Damage model is not useful in this case.