An approximate analysis for free vibration of a laminated curved panel(shell)with four edges simply supported(SS2),is presented in this paper.The transverse shear deformation is considered by using a higher-order shea...An approximate analysis for free vibration of a laminated curved panel(shell)with four edges simply supported(SS2),is presented in this paper.The transverse shear deformation is considered by using a higher-order shear deformation theory.For solving the highly coupled partial differential governing equations and associated boundary conditions,a set of solution functions in the form of double trigonometric Fourier series,which are required to satisfy the geometry part of the considered boundary conditions,is assumed in advance.By applying the Galerkin procedure both to the governing equations and to the natural boundary conditions not satisfied by the assumed solution functions,an approximate solution,capable of providing a reliable prediction for the global response of the panel,is obtained.Numerical results of antisymmetric angle-ply as well as symmetric cross-ply and angle-ply laminated curved panels are presented and discussed.展开更多
For the development of high-strength Mg alloys,active use of Laves phases such as C14-type Mg_(2)Yb and Mg_(2)Ca is strongly expected.However,the brittleness of the Laves phases is the biggest obstacle to it.We first ...For the development of high-strength Mg alloys,active use of Laves phases such as C14-type Mg_(2)Yb and Mg_(2)Ca is strongly expected.However,the brittleness of the Laves phases is the biggest obstacle to it.We first found that kink-band formation can be induced in directionally solidified Mg/Mg_(2)Yb and Mg/Mg_(2)Ca eutectic lamellar alloys when a stress is applied parallel to the lamellar interface,leading to a high yield stress accompanied with ductility.That is,microstructural control can induce a new deformation mode that is not activated in the constituent phases,thereby inducing ductility.It was clarified that the geometric relationship between the operative slip plane in the constituent phases and the lamellar interface,and the microstructural features that provide kink-band nucleation sites are important factors for controlling kink-band formation.The obtained results show a possibility to open the new door for the development of novel high-strength structural material using the kink bands.展开更多
This study performed the time-resolved and in-situ observation of unidirectional solidification of A1-Cu and Sn-Bi alloys under a static magnetic field up to 0.45 T.Irt the case of Sn-Bi alloy,the static magnetic fiel...This study performed the time-resolved and in-situ observation of unidirectional solidification of A1-Cu and Sn-Bi alloys under a static magnetic field up to 0.45 T.Irt the case of Sn-Bi alloy,the static magnetic field reduced the local convection around the primary dendrite arms.No thermoelectric convection was detected.On the other hand,the thermoelectric convection was clearly observed in Al-Cu alloy.The observed convection was consistently explained by the thermoelectric magnetic convection.According to a simplified model,the thermoelectric magnetic convection can be induced if the difference in the thermoelectric power between the solid and the liquid phases is in the order of 1 μV/K and temperature gradient is several K/mm.展开更多
It has been reported that an anisotropic magnetic field could produce the three-dimensional alignment of fine single-crystal particles with the orthorhombic crystal structure.However,the three-dimensional alignment wa...It has been reported that an anisotropic magnetic field could produce the three-dimensional alignment of fine single-crystal particles with the orthorhombic crystal structure.However,the three-dimensional alignment was achieved only in suspensions.Fabrication of bulk 'single' materials that have the three-dimensional alignment of grains has been desired.This study proposes a procedure for the fabrication,which consists of slip casting under an oscillating magnetic field and sintering.Optimization of casting and sintering conditions achieved the three-dimensionally aligned bulk β-FeSi_2.展开更多
文摘An approximate analysis for free vibration of a laminated curved panel(shell)with four edges simply supported(SS2),is presented in this paper.The transverse shear deformation is considered by using a higher-order shear deformation theory.For solving the highly coupled partial differential governing equations and associated boundary conditions,a set of solution functions in the form of double trigonometric Fourier series,which are required to satisfy the geometry part of the considered boundary conditions,is assumed in advance.By applying the Galerkin procedure both to the governing equations and to the natural boundary conditions not satisfied by the assumed solution functions,an approximate solution,capable of providing a reliable prediction for the global response of the panel,is obtained.Numerical results of antisymmetric angle-ply as well as symmetric cross-ply and angle-ply laminated curved panels are presented and discussed.
基金supported by Japan Society for the Promotion of Science (JSPS) KAKENHI for Scientific Research on Innovative Areas "MFS Materials Science" (Grant Numbers: JP18H05478 and JP18H05475)partly supported by the Light Metals Educational Foundation of Japan。
文摘For the development of high-strength Mg alloys,active use of Laves phases such as C14-type Mg_(2)Yb and Mg_(2)Ca is strongly expected.However,the brittleness of the Laves phases is the biggest obstacle to it.We first found that kink-band formation can be induced in directionally solidified Mg/Mg_(2)Yb and Mg/Mg_(2)Ca eutectic lamellar alloys when a stress is applied parallel to the lamellar interface,leading to a high yield stress accompanied with ductility.That is,microstructural control can induce a new deformation mode that is not activated in the constituent phases,thereby inducing ductility.It was clarified that the geometric relationship between the operative slip plane in the constituent phases and the lamellar interface,and the microstructural features that provide kink-band nucleation sites are important factors for controlling kink-band formation.The obtained results show a possibility to open the new door for the development of novel high-strength structural material using the kink bands.
基金supported in part by a Grant-in-Aidfor Scientific Research (A) & (S) and the Global COE Program from the Ministry of Education+3 种基金CultureSportsScience and TechnologyJapan
文摘This study performed the time-resolved and in-situ observation of unidirectional solidification of A1-Cu and Sn-Bi alloys under a static magnetic field up to 0.45 T.Irt the case of Sn-Bi alloy,the static magnetic field reduced the local convection around the primary dendrite arms.No thermoelectric convection was detected.On the other hand,the thermoelectric convection was clearly observed in Al-Cu alloy.The observed convection was consistently explained by the thermoelectric magnetic convection.According to a simplified model,the thermoelectric magnetic convection can be induced if the difference in the thermoelectric power between the solid and the liquid phases is in the order of 1 μV/K and temperature gradient is several K/mm.
基金supported by Grant-in-Aid for Scientific Research (Challenging Exploratory Research) (A) and (S)
文摘It has been reported that an anisotropic magnetic field could produce the three-dimensional alignment of fine single-crystal particles with the orthorhombic crystal structure.However,the three-dimensional alignment was achieved only in suspensions.Fabrication of bulk 'single' materials that have the three-dimensional alignment of grains has been desired.This study proposes a procedure for the fabrication,which consists of slip casting under an oscillating magnetic field and sintering.Optimization of casting and sintering conditions achieved the three-dimensionally aligned bulk β-FeSi_2.