This paper shows a calculation model and a method for predicting the tensile strength of the random distributed short fiber composite.On the basis of Renjie Mao's model,the longitudinal tensile strength of the ali...This paper shows a calculation model and a method for predicting the tensile strength of the random distributed short fiber composite.On the basis of Renjie Mao's model,the longitudinal tensile strength of the aligned short fiber composite is formulated.Considering the transverse tensile strength and in plane shear strength of the unidirectional fiber composite,and the stress transformation relations of two couples of axes,the stress of the unidirectional fiber composite when it is loaded at an arbitrary angle is obtained.With the aid of an equivalence relation,the calculation formulation of the tensile strength of the random short fiber reinforced composite is deduced.展开更多
Based on tensile cracking of SiC_p and decohesion of the interface between SiC_p and Al matrix, a mesomechanical model for tensile deformation of SiC_p/Al composites was developed. The microcracks and multi-scale seco...Based on tensile cracking of SiC_p and decohesion of the interface between SiC_p and Al matrix, a mesomechanical model for tensile deformation of SiC_p/Al composites was developed. The microcracks and multi-scale second phase particles were assumed to distribute homogeneously. A nonlinear quantitative relationship between tensile ductility and volume fraction of SiC_p was established based on the model. The tensile ductility values of 2xxx SiC_p/Al and 6xxx SiC_p/Al composites predicted by the model are in good agreement with the experimental values. The analysis of effects of multi-scale second phases on the ductility of the composites indicates that the ductility decreases with the increase of the volume fraction of SiC_p and precipitates in Al matrix and is almost independent of constituents and dispersoids.展开更多
Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene（reduced graphene oxide） reinforced aluminum...Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene（reduced graphene oxide） reinforced aluminum（Al）matrix composites were fabricated by flaky powder metallurgy. Tensile tests of pure Al matrix and graphene/Al composites with bioinspired layered structures are conducted.By means of an independently developed Python-based structural modeling program, three-dimensional microscopic structural models of graphene/Al composites can be established, in which the size, shape, orientation, location and content of graphene can be reconstructed in line with the actual graphene/Al composite structures. Elastoplastic mechanical properties, damaged materials behaviors, grapheneAl interfacial behaviors and reasonable boundary conditions are introduced and applied to perform the simulations. Based on the experimental and numerical tensile behaviors of graphene/Al composites, the effects of graphene morphology,graphene-Al interface, composite configuration and failure behavior within the tensile mechanical deformations of graphene/Al composites can be revealed and indicated, respectively.From the analysis above, a good understanding can be brought to light for the deformation mechanism of graphene/Al composites.展开更多
文摘This paper shows a calculation model and a method for predicting the tensile strength of the random distributed short fiber composite.On the basis of Renjie Mao's model,the longitudinal tensile strength of the aligned short fiber composite is formulated.Considering the transverse tensile strength and in plane shear strength of the unidirectional fiber composite,and the stress transformation relations of two couples of axes,the stress of the unidirectional fiber composite when it is loaded at an arbitrary angle is obtained.With the aid of an equivalence relation,the calculation formulation of the tensile strength of the random short fiber reinforced composite is deduced.
基金Project(2005CB623704) supported bythe National Basic Research Programof China Project(NCET-04-0753) supportedby the New Century Talented Professionals Programof Chinese Education Ministry
文摘Based on tensile cracking of SiC_p and decohesion of the interface between SiC_p and Al matrix, a mesomechanical model for tensile deformation of SiC_p/Al composites was developed. The microcracks and multi-scale second phase particles were assumed to distribute homogeneously. A nonlinear quantitative relationship between tensile ductility and volume fraction of SiC_p was established based on the model. The tensile ductility values of 2xxx SiC_p/Al and 6xxx SiC_p/Al composites predicted by the model are in good agreement with the experimental values. The analysis of effects of multi-scale second phases on the ductility of the composites indicates that the ductility decreases with the increase of the volume fraction of SiC_p and precipitates in Al matrix and is almost independent of constituents and dispersoids.
基金financial supports by the National Natural Science Foundation (51501111, 51131004)the Ministry of Science and Technology of China (2016YFE0130200)+1 种基金Science & Technology Committee of Shanghai (14DZ2261200, 1452 0710100 and 14JC14033 00)111 Project (B16032)
文摘Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene（reduced graphene oxide） reinforced aluminum（Al）matrix composites were fabricated by flaky powder metallurgy. Tensile tests of pure Al matrix and graphene/Al composites with bioinspired layered structures are conducted.By means of an independently developed Python-based structural modeling program, three-dimensional microscopic structural models of graphene/Al composites can be established, in which the size, shape, orientation, location and content of graphene can be reconstructed in line with the actual graphene/Al composite structures. Elastoplastic mechanical properties, damaged materials behaviors, grapheneAl interfacial behaviors and reasonable boundary conditions are introduced and applied to perform the simulations. Based on the experimental and numerical tensile behaviors of graphene/Al composites, the effects of graphene morphology,graphene-Al interface, composite configuration and failure behavior within the tensile mechanical deformations of graphene/Al composites can be revealed and indicated, respectively.From the analysis above, a good understanding can be brought to light for the deformation mechanism of graphene/Al composites.
