The Experts below are selected from a list of 14019 Experts worldwide ranked by ideXlab platform
Hiroshi Noguchi - One of the best experts on this subject based on the ideXlab platform.
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Microstructural mechanisms of fatigue crack non-propagation in TRIP-maraging steels
International Journal of Fatigue, 2018Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasan, Hiroshi NoguchiAbstract:Abstract In contrast to conventional martensitic steels, transformation-induced plasticity (TRIP)-maraging steels exhibit exceptional high ductility without sacrificing strength and excellent fatigue property owing to the retained austenite/maraging martensite Laminated Structure. In this study, TRIP-maraging steel (Fe-9Mn-3Ni-1.4Al-0.01C, wt.%) with fine grained austenite was used to investigate the mechanism of high cycle fatigue resistance. Our analyses revealed that soft austenite region acts as a preferential crack propagation path, but the plastic deformation during crack opening involves martensitic transformation, resisting subsequent crack growth via transformation-induced local hardening or crack closure. Moreover, crack growth along the laminates and across the block boundary forms a zigzag crack path, which would act as roughness-induced crack closure. The combined effect of these factors plays an important role in resisting fatigue crack growth at high cycle fatigue.
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effects of lamella size and connectivity on fatigue crack resistance of trip maraging steel
International Journal of Fatigue, 2017Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasa, Hiroshi NoguchiAbstract:Abstract The effect of austenitization time on the fatigue crack resistance of transformation-induced plasticity (TRIP)-maraging steel was investigated by observing the crack initiation site, propagation path and fracture surface. Our analyses show that austenitization for a longer time increases austenite/martensite lamella size and connectivity of austenite. Simultaneously, increasing lamella size leads to a reduction in austenite hardness; higher austenite connectivity accelerates crack propagation. In addition, remarkable roughness on the crack surface associated with the Laminated Structure was observed in both steels, which caused roughness-induced crack closure.
Qing Han - One of the best experts on this subject based on the ideXlab platform.
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research on finite element model modification of carbon fiber reinforced plastic cfrp Laminated Structures based on correlation analysis and an approximate model
Materials, 2019Co-Authors: Yizheng Zhang, Yue Yang, Qing HanAbstract:Carbon fiber reinforced plastic (CFRP) Laminated Structures have been widely used in modern engineering due to their excellent material properties, especially in the aerospace and shipping industries. This requires a high-accuracy finite element model of CFRP Laminated Structures. However, it is difficult to master the mechanical properties of CFRP Structures comprehensively and accurately due to influences from multiple aspects, such as dispersion of material properties, uncertainty of manufacturing technologies, etc. Therefore, a finite element model modification method of CFRP Laminated Structures based on correlation analysis and an approximate model was proposed. Aiming at minimizing the difference between the analysis model and the measured inherent frequency, the proposed method improves the finite element modeling accuracy of CFRP Laminated Structures, by iterative optimization based on a global optimization algorithm. In order to solve the problem of high spatial dimension and slow searching in modification of CFRP Laminated Structure models, the Pearson correlation analysis method was used to screen the material parameters which exert significant impacts on frequency characteristics to reconstruct the searching space. Based on significance parameters, an approximate response model of the CFRP Laminated structural system was established. Meanwhile, the modeling accuracy of different orders of response surface models (RSM) and a radial basis function (RBF) neural network model was analyzed, and the best approximate modeling scheme was obtained. The approximate model was updated based on the multi-island genetic algorithm (MIGA) to modify the finite element model of the CFRP Laminated Structure model. The maximum error and mean error of the updated model are 1.47% and 0.45%. It was proved that the material parameters modified by the proposed method are applicable to simulation analysis of the CFRP Laminated Structure.
Meimei Wang - One of the best experts on this subject based on the ideXlab platform.
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Microstructural mechanisms of fatigue crack non-propagation in TRIP-maraging steels
International Journal of Fatigue, 2018Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasan, Hiroshi NoguchiAbstract:Abstract In contrast to conventional martensitic steels, transformation-induced plasticity (TRIP)-maraging steels exhibit exceptional high ductility without sacrificing strength and excellent fatigue property owing to the retained austenite/maraging martensite Laminated Structure. In this study, TRIP-maraging steel (Fe-9Mn-3Ni-1.4Al-0.01C, wt.%) with fine grained austenite was used to investigate the mechanism of high cycle fatigue resistance. Our analyses revealed that soft austenite region acts as a preferential crack propagation path, but the plastic deformation during crack opening involves martensitic transformation, resisting subsequent crack growth via transformation-induced local hardening or crack closure. Moreover, crack growth along the laminates and across the block boundary forms a zigzag crack path, which would act as roughness-induced crack closure. The combined effect of these factors plays an important role in resisting fatigue crack growth at high cycle fatigue.
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effects of lamella size and connectivity on fatigue crack resistance of trip maraging steel
International Journal of Fatigue, 2017Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasa, Hiroshi NoguchiAbstract:Abstract The effect of austenitization time on the fatigue crack resistance of transformation-induced plasticity (TRIP)-maraging steel was investigated by observing the crack initiation site, propagation path and fracture surface. Our analyses show that austenitization for a longer time increases austenite/martensite lamella size and connectivity of austenite. Simultaneously, increasing lamella size leads to a reduction in austenite hardness; higher austenite connectivity accelerates crack propagation. In addition, remarkable roughness on the crack surface associated with the Laminated Structure was observed in both steels, which caused roughness-induced crack closure.
Zhao Zhang - One of the best experts on this subject based on the ideXlab platform.
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Microstructural mechanisms of fatigue crack non-propagation in TRIP-maraging steels
International Journal of Fatigue, 2018Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasan, Hiroshi NoguchiAbstract:Abstract In contrast to conventional martensitic steels, transformation-induced plasticity (TRIP)-maraging steels exhibit exceptional high ductility without sacrificing strength and excellent fatigue property owing to the retained austenite/maraging martensite Laminated Structure. In this study, TRIP-maraging steel (Fe-9Mn-3Ni-1.4Al-0.01C, wt.%) with fine grained austenite was used to investigate the mechanism of high cycle fatigue resistance. Our analyses revealed that soft austenite region acts as a preferential crack propagation path, but the plastic deformation during crack opening involves martensitic transformation, resisting subsequent crack growth via transformation-induced local hardening or crack closure. Moreover, crack growth along the laminates and across the block boundary forms a zigzag crack path, which would act as roughness-induced crack closure. The combined effect of these factors plays an important role in resisting fatigue crack growth at high cycle fatigue.
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effects of lamella size and connectivity on fatigue crack resistance of trip maraging steel
International Journal of Fatigue, 2017Co-Authors: Zhao Zhang, Motomichi Koyama, Meimei Wang, Kaneaki Tsuzaki, Cemal Cem Tasa, Hiroshi NoguchiAbstract:Abstract The effect of austenitization time on the fatigue crack resistance of transformation-induced plasticity (TRIP)-maraging steel was investigated by observing the crack initiation site, propagation path and fracture surface. Our analyses show that austenitization for a longer time increases austenite/martensite lamella size and connectivity of austenite. Simultaneously, increasing lamella size leads to a reduction in austenite hardness; higher austenite connectivity accelerates crack propagation. In addition, remarkable roughness on the crack surface associated with the Laminated Structure was observed in both steels, which caused roughness-induced crack closure.
Yizheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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research on finite element model modification of carbon fiber reinforced plastic cfrp Laminated Structures based on correlation analysis and an approximate model
Materials, 2019Co-Authors: Yizheng Zhang, Yue Yang, Qing HanAbstract:Carbon fiber reinforced plastic (CFRP) Laminated Structures have been widely used in modern engineering due to their excellent material properties, especially in the aerospace and shipping industries. This requires a high-accuracy finite element model of CFRP Laminated Structures. However, it is difficult to master the mechanical properties of CFRP Structures comprehensively and accurately due to influences from multiple aspects, such as dispersion of material properties, uncertainty of manufacturing technologies, etc. Therefore, a finite element model modification method of CFRP Laminated Structures based on correlation analysis and an approximate model was proposed. Aiming at minimizing the difference between the analysis model and the measured inherent frequency, the proposed method improves the finite element modeling accuracy of CFRP Laminated Structures, by iterative optimization based on a global optimization algorithm. In order to solve the problem of high spatial dimension and slow searching in modification of CFRP Laminated Structure models, the Pearson correlation analysis method was used to screen the material parameters which exert significant impacts on frequency characteristics to reconstruct the searching space. Based on significance parameters, an approximate response model of the CFRP Laminated structural system was established. Meanwhile, the modeling accuracy of different orders of response surface models (RSM) and a radial basis function (RBF) neural network model was analyzed, and the best approximate modeling scheme was obtained. The approximate model was updated based on the multi-island genetic algorithm (MIGA) to modify the finite element model of the CFRP Laminated Structure model. The maximum error and mean error of the updated model are 1.47% and 0.45%. It was proved that the material parameters modified by the proposed method are applicable to simulation analysis of the CFRP Laminated Structure.
