The Experts below are selected from a list of 177798 Experts worldwide ranked by ideXlab platform
Seonggu Hong - One of the best experts on this subject based on the ideXlab platform.
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application of Local Stress strain approaches in the prediction of fatigue crack initiation life for cyclically non stabilized and non masing steel
International Journal of Fatigue, 2005Co-Authors: Seonggu HongAbstract:Abstract This study presents a methodology of life prediction of fatigue crack initiation for the cyclically non-stabilized and non-Masing steel. The cyclic behavior of 316L stainless steel was modelled, and the constitutive model was combined with Local Stress–strain approximations at a notch. The Local Stress–strain approximation methods were formulated incrementally to get the notch tip Stress–strain of the non-Masing material. The Local approximations were compared with the FEM results for verification. The prediction of fatigue crack initiation life was carried out by adopting plastic strain energy density (PSED) as a fatigue parameter and all the life prediction results were within factors of two of the experimental results.
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application of Local Stress strain approaches in the prediction of fatigue crack initiation life for cyclically non stabilized and non masing steel
International Journal of Fatigue, 2005Co-Authors: Seonggu HongAbstract:Abstract This study presents a methodology of life prediction of fatigue crack initiation for the cyclically non-stabilized and non-Masing steel. The cyclic behavior of 316L stainless steel was modelled, and the constitutive model was combined with Local Stress–strain approximations at a notch. The Local Stress–strain approximation methods were formulated incrementally to get the notch tip Stress–strain of the non-Masing material. The Local approximations were compared with the FEM results for verification. The prediction of fatigue crack initiation life was carried out by adopting plastic strain energy density (PSED) as a fatigue parameter and all the life prediction results were within factors of two of the experimental results.
Weixing Yao - One of the best experts on this subject based on the ideXlab platform.
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Local Stress strain field intensity approach to fatigue life prediction under random cyclic loading
International Journal of Fatigue, 2001Co-Authors: Deguang Shang, Dakang Wang, Weixing YaoAbstract:Abstract According to the characteristic of the Local behavior of fatigue damage, on the basis of Stress field intensity approach, a theory of Local Stress–strain field intensity for fatigue damage at the notch is developed in this paper, which can take account of the effects of the Local Stress–strain gradient on fatigue damage at the notch. In order to calculate the Local Stress–strain field intensity parameters, an incremental elastic-plastic finite element analysis under random cyclic loading is used to determine the Local Stress–strain response. A Local Stress–strain field intensity approach to fatigue life prediction is proposed by means of elastic-plastic finite element method for notched specimens. This approach is used to predict fatigue crack initiation life, and good correlation was observed with U-shape notched specimens for normalized 45 steel.
Chiara Bisagni - One of the best experts on this subject based on the ideXlab platform.
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fatigue analysis of a post buckled composite single stringer specimen taking into account the Local Stress ratio
Composites Part B-engineering, 2020Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:The fatigue life prediction of post-buckled composite structures represents still an unresolved issue due to the complexity of the phenomenon and the high costs of experimental testing. In this paper, a novel numerical approach, called “Min-Max Load Approach”, is used to analyze the behavior of a composite single-stringer specimen with an initial skin-stringer delamination subjected to post-buckling fatigue compressive load. The proposed approach, based on cohesive zone model technique, is able to evaluate the Local Stress ratio during the delamination growth, performing, in a single Finite Element analysis, the simulation of the structure at the maximum and minimum load of the fatigue cycle. The knowledge of the actual value of the Local Stress ratio is crucial to correctly calculate the crack growth rate. At first, the specimen is analyzed under quasi-static loading conditions, then the fatigue simulation is performed. The results of the numerical analysis are compared with the data of an experimental campaign previously conducted, showing the capabilities of the proposed approach.
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analysis of Local Stress ratio for delamination in composites under fatigue loads
AIAA Journal, 2020Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:An approach based on the cohesive zone model for analyzing delamination in composite laminates under cyclic fatigue loading is presented. The proposed technique, called “min-max load approach,” is able to dynamically capture the Local Stress ratio during the progression of delamination. The possibility to know the Local Stress ratio is relevant in all the situations where its value is different from the applied load ratio and cannot be determined a priori. The methodology analyzes in a single finite element analysis two identical models with two different constant loads, the minimum and the maximum load of the fatigue cycle. The two models interact with each other, exchanging information to calculate the crack growth rate. At first, the approach has been validated in simulations of mode I and mixed-mode propagation using double cantilever beam and mixed-mode bending tests. Then, to prove the effectiveness of the developed methodology, a modified version of the mixed-mode bending test has been analyzed. Mode I and mode II components of the load are decoupled and applied independently, resulting in a Local Stress ratio different from the applied load ratio. The results obtained from the simulations, compared with the analytical model obtained using the corrected beam theory, show that the proposed approach is able to predict the Local Stress ratio and thereby to correctly evaluate the crack growth rate during the propagation of the damage.
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a numerical approach for the evaluation of the Local Stress ratio in fatigue driven delamination analysis
AIAA Scitech 2019 Forum, 2019Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:An approach based on the cohesive zone model for analyzing fatigue-driven delamination in composite structures under cyclic loading is presented. The proposed technique, called “Min-Max Load Approach”, is able to dynamically capture the Local Stress ratio during the evolution of damage. The possibility to know the Local Stress ratio is relevant in all the situations where its value is different from the applied load ratio and cannot be determined a priori. In a single Finite Element analysis, two identical models are analyzed with two different constant loads, the minimum and the maximum load during the fatigue cycle. The implemented methodology allows the two models to interact with each other, by exchanging information to correctly calculate the crack growth rate. At first, the approach has been validated in simulations of mode I and mixed-mode propagation by using Double Cantilever Beam and Mixed-Mode Bending. Then, to prove the effectiveness of the developed methodology, a modified version of the Mixed-Mode Bending test has been numerically investigated. In this test, the mode I and mode II components of the load are decoupled and applied independently, resulting in a Local Stress ratio different from the applied load ratio.
Deguang Shang - One of the best experts on this subject based on the ideXlab platform.
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Local Stress strain field intensity approach to fatigue life prediction under random cyclic loading
International Journal of Fatigue, 2001Co-Authors: Deguang Shang, Dakang Wang, Weixing YaoAbstract:Abstract According to the characteristic of the Local behavior of fatigue damage, on the basis of Stress field intensity approach, a theory of Local Stress–strain field intensity for fatigue damage at the notch is developed in this paper, which can take account of the effects of the Local Stress–strain gradient on fatigue damage at the notch. In order to calculate the Local Stress–strain field intensity parameters, an incremental elastic-plastic finite element analysis under random cyclic loading is used to determine the Local Stress–strain response. A Local Stress–strain field intensity approach to fatigue life prediction is proposed by means of elastic-plastic finite element method for notched specimens. This approach is used to predict fatigue crack initiation life, and good correlation was observed with U-shape notched specimens for normalized 45 steel.
Antonio Raimondo - One of the best experts on this subject based on the ideXlab platform.
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fatigue analysis of a post buckled composite single stringer specimen taking into account the Local Stress ratio
Composites Part B-engineering, 2020Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:The fatigue life prediction of post-buckled composite structures represents still an unresolved issue due to the complexity of the phenomenon and the high costs of experimental testing. In this paper, a novel numerical approach, called “Min-Max Load Approach”, is used to analyze the behavior of a composite single-stringer specimen with an initial skin-stringer delamination subjected to post-buckling fatigue compressive load. The proposed approach, based on cohesive zone model technique, is able to evaluate the Local Stress ratio during the delamination growth, performing, in a single Finite Element analysis, the simulation of the structure at the maximum and minimum load of the fatigue cycle. The knowledge of the actual value of the Local Stress ratio is crucial to correctly calculate the crack growth rate. At first, the specimen is analyzed under quasi-static loading conditions, then the fatigue simulation is performed. The results of the numerical analysis are compared with the data of an experimental campaign previously conducted, showing the capabilities of the proposed approach.
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analysis of Local Stress ratio for delamination in composites under fatigue loads
AIAA Journal, 2020Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:An approach based on the cohesive zone model for analyzing delamination in composite laminates under cyclic fatigue loading is presented. The proposed technique, called “min-max load approach,” is able to dynamically capture the Local Stress ratio during the progression of delamination. The possibility to know the Local Stress ratio is relevant in all the situations where its value is different from the applied load ratio and cannot be determined a priori. The methodology analyzes in a single finite element analysis two identical models with two different constant loads, the minimum and the maximum load of the fatigue cycle. The two models interact with each other, exchanging information to calculate the crack growth rate. At first, the approach has been validated in simulations of mode I and mixed-mode propagation using double cantilever beam and mixed-mode bending tests. Then, to prove the effectiveness of the developed methodology, a modified version of the mixed-mode bending test has been analyzed. Mode I and mode II components of the load are decoupled and applied independently, resulting in a Local Stress ratio different from the applied load ratio. The results obtained from the simulations, compared with the analytical model obtained using the corrected beam theory, show that the proposed approach is able to predict the Local Stress ratio and thereby to correctly evaluate the crack growth rate during the propagation of the damage.
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a numerical approach for the evaluation of the Local Stress ratio in fatigue driven delamination analysis
AIAA Scitech 2019 Forum, 2019Co-Authors: Antonio Raimondo, Chiara BisagniAbstract:An approach based on the cohesive zone model for analyzing fatigue-driven delamination in composite structures under cyclic loading is presented. The proposed technique, called “Min-Max Load Approach”, is able to dynamically capture the Local Stress ratio during the evolution of damage. The possibility to know the Local Stress ratio is relevant in all the situations where its value is different from the applied load ratio and cannot be determined a priori. In a single Finite Element analysis, two identical models are analyzed with two different constant loads, the minimum and the maximum load during the fatigue cycle. The implemented methodology allows the two models to interact with each other, by exchanging information to correctly calculate the crack growth rate. At first, the approach has been validated in simulations of mode I and mixed-mode propagation by using Double Cantilever Beam and Mixed-Mode Bending. Then, to prove the effectiveness of the developed methodology, a modified version of the Mixed-Mode Bending test has been numerically investigated. In this test, the mode I and mode II components of the load are decoupled and applied independently, resulting in a Local Stress ratio different from the applied load ratio.
