1,722,020 research outputs found
Unified-error Filtered-x LMS Algorithm for On-line Active Noise Control in Time-varying Environment
No full textCollapse Analysis of Space-framed Vehicle Models by Finite Element Limit Analysis
Full text link1998 SAE Int. Congress, Detroit, U.S.A., 1998.The present analysis concerns collapse behavior of vehicles under the quasi-static loading condition as analysis for the initial stage of conceptual design. Collapse analysis of a vehicle model with the space-framed structure is carried out using finite element limit analysis. To improve collapse response and strengthen weak parts, the dimension of the section and the position of the frame are locally changed as design parameters. The results demonstrates that the present analysis can easily predict weak parts of the structure and the change of design parameters enhances the load-carrying capacity of vehicle structures and reduces the deflection toward the passenger compartment
Effects of constrained groove pressing on mechanical properties of a TWIP steel
No full textThe evolution of mechanical properties and microstructure of a twinning induced plasticity (TWIP) steel sheet during constrained groove pressing (CGP) was investigated. It was found that by imposing CGP, the volume fraction of twins, hardness and yield strength increase significantly, while ductility decreases. The results of the pin-on-disk wear test showed that the CGP process improves the wear resistance of the TWIP steel, where oxidation is the main wear mechanism. The effect of annealing treatment at various temperatures on the hardness evolution of the CGP-treated samples was also investigated. Moreover, a modified work-hardening model was applied to predict the flow behaviour of TWIP steel during the severe plastic deformation. The model successfully predicts the flow curve and measured dislocation density and twin evolution. © 2021 Institute of Materials, Minerals and Mining.11Nsciescopu
Study of Geometrically Necessary Dislocations of a Partially Recrystallized Aluminum Alloy Using 2D EBSD
No full textDuring recrystallization, the growth of fresh grains initiated within a deformed microstructure causes dramatic changes in the dislocation structure and density of a heavily deformed matrix. In this paper, the microstructure of a cold rolled and partially recrystallized Al-Mg alloy (AA5052) was studied via electron backscattered diffraction (EBSD) analysis. The structure and density of the geometrically necessary dislocations (GNDs) were predicted using a combination of continuum mechanics and dislocation theory. Accordingly, the Nye dislocation tensor, which determines the GND structure, was estimated by calculation of the lattice curvature. To do so, five components of the Nye dislocation tensor were directly calculated from the local orientation of surface points of the specimen, which was determined by two-dimensional EBSD. The remaining components of GNDs were determined by minimizing a normalized Hamiltonian equation based on dislocation energy. The results show the elimination of low angle boundaries, lattice curvature, and GNDs in recrystallized regions and the formation of low angle boundaries with orientation discontinuities in deformed grains, which may be due to static recovery.11Nsciescopu
Experimental study on volume change of gas hydrate-bearing sediments during gas hydrate dissociation
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A comprehensive analysis procedure for predicting the performance of a molten carbonate fuel cell
No full textConstitutive modeling of deformation behavior of high-entropy alloys with face-centered cubic crystal structure
Full text linkA constitutive model based on the dislocation glide and deformation twinning is adapted to face-centered cubic high-entropy alloys (HEAs) as exemplified by the CrMnFeCoNi system. In this model, the total dislocation density is considered as the only internal variable, while the evolution equation describing its variation during plastic deformation is governed by the volume fraction of twinned material. The suitability of the model for describing the strain hardening behavior of HEAs was verified experimentally through compression tests on alloy CrMnFeCoNi and its microstructure characterization by electron backscatter diffraction and X-ray diffraction using synchrotron radiation. ? 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.1111Ysciescopu
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