In this paper, we developed the theory and algorithm of an elastic one-way boundary element method(BEM) and a corresponding hybrid elastic thin-slab propagator for earth media with sharp boundaries between strong cont...In this paper, we developed the theory and algorithm of an elastic one-way boundary element method(BEM) and a corresponding hybrid elastic thin-slab propagator for earth media with sharp boundaries between strong contrast media. This approach can takes the advantage of accurate boundary condition of BEM and completely overcomes the weak contrast limitation of the perturbationtheory based one-way operator approach. The one-way BEM is a smooth boundary approximation, which avoids huge matrix operations in exact full BEM. In addition, the one-way BEM can model the primary-only transmitted and reflected waves and therefore is a valuable tool in elastic imaging and inversion. Through numerical tests for some simple models,we proved the validity and efficiency of the proposed method.展开更多
Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation.In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid ...Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation.In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid core reduction on thin-slab continuous casting,suggests the fluid-solid coupling method should be used to research the characteristic and patterns of slab deformation during the liquid core reduction process,as well as research liquid core backflows.A material model of the slab shell was obtained through the high-temperature compression test of the cast steel.The analysis of the fluid-solid coupling simulation for liquid core reduction shows that slab deformation concentrates on the narrow side due to the existence of the liquid core.Meanwhile,the stress and strain increases with the increase of the reduction rate and slab thickness.The changing trends of stress and strain are identical under various conditions.The results demonstrate that using greater reduction at the upper part of the slab,which has a higher temperature and thinner slab,is beneficial to the quality of the slab.Moreover,the liquid core is extruded as the reduction is implemented.The quantity of the extrusion increases with the increase of reduction rate and the thickness of thinner shell,which leads to fluctuation of the mould level,making the operation more difficult.展开更多
基金supported by National Scientific Foundation of China with Grant No. 41774067
文摘In this paper, we developed the theory and algorithm of an elastic one-way boundary element method(BEM) and a corresponding hybrid elastic thin-slab propagator for earth media with sharp boundaries between strong contrast media. This approach can takes the advantage of accurate boundary condition of BEM and completely overcomes the weak contrast limitation of the perturbationtheory based one-way operator approach. The one-way BEM is a smooth boundary approximation, which avoids huge matrix operations in exact full BEM. In addition, the one-way BEM can model the primary-only transmitted and reflected waves and therefore is a valuable tool in elastic imaging and inversion. Through numerical tests for some simple models,we proved the validity and efficiency of the proposed method.
文摘Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation.In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid core reduction on thin-slab continuous casting,suggests the fluid-solid coupling method should be used to research the characteristic and patterns of slab deformation during the liquid core reduction process,as well as research liquid core backflows.A material model of the slab shell was obtained through the high-temperature compression test of the cast steel.The analysis of the fluid-solid coupling simulation for liquid core reduction shows that slab deformation concentrates on the narrow side due to the existence of the liquid core.Meanwhile,the stress and strain increases with the increase of the reduction rate and slab thickness.The changing trends of stress and strain are identical under various conditions.The results demonstrate that using greater reduction at the upper part of the slab,which has a higher temperature and thinner slab,is beneficial to the quality of the slab.Moreover,the liquid core is extruded as the reduction is implemented.The quantity of the extrusion increases with the increase of reduction rate and the thickness of thinner shell,which leads to fluctuation of the mould level,making the operation more difficult.
