http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
신동욱,Viswanathan S. Saji,Ravindra K. Gupta,조용수 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.11
The variations of physical and dielectric properties of low temperature dielectrics based on typical aluminoborosilicate glasses modified with several divalent oxides were investigated. The divalent oxides studied here included CaO, MgO, BaO, SrO and ZnO. All samples containing either 35 wt% or 45 wt% alumina filler were prepared at the same processing condition and then fired at 850oC for 30 min. The resultant characteristics of fired samples depended on the choice of the divalent ion and the content of the alumina filler. Except for the ZnO modification, all other samples containing 35 wt% filler demonstrated promising densification as they exhibited reasonably high densities of 3.07-3.31 g/cm3 and high shrinkages of 14.0-16.4%. Particularly, the sample containing ZnO was distinguished with large variations compared to the base sample, which can be highlighted with earlier densification and crystallization at unexpectedly low temperatures. The negative effects of the ZnO modification on densification and dielectric properties were thought to be associated with earlier crystallization potentially by influencing effective densification via viscous flow. As an optimum composition, the sample containing only CaO showed the most promising characteristics such as k~8.05 and tanδ~0.0018 when 35 wt% alumina filler was used.
K.K.Viswanathan,Z. A. Aziz,Saira Javed,Y. Yaacob,Babuji Pullepu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.5
Free vibration of symmetric angle-ply laminated truncated conical shell is analyzed to determine the effects of frequency parameterand angular frequencies under different boundary condition, ply angles, different material properties and other parameters. The governingequations of motion for truncated conical shell are obtained in terms of displacement functions. The displacement functions are approximatedby cubic and quintic splines resulting into a generalized eigenvalue problem. The parametric studies have been made and discussed.
K.K.Viswanathan,Saira Javed,Zainal Abdul Aziz 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2
Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness is analyzed under shear deformation theory with different boundary conditions by applying collocation with spline approximation. Linear and exponential variation in thickness of layers are assumed in axial direction. Displacements and rotational functions are approximated by Bickley-type splines of order three and obtained a generalized eigenvalue problem. This problem is solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration of three and five–layered conical shells, made up of two different type of materials are considered. Parametric studies are made for analysing the frequencies of the shell with respect to the coefficients of thickness variations, length-to-radius ratio, length-to-thickness ratio and ply angles with different combination of the materials. The results are compared with the available data and new results are presented in terms of tables and graphs.
Viswanathan, K.K.,Javed, Saira,Aziz, Zainal Abdul Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2
Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness is analyzed under shear deformation theory with different boundary conditions by applying collocation with spline approximation. Linear and exponential variation in thickness of layers are assumed in axial direction. Displacements and rotational functions are approximated by Bickley-type splines of order three and obtained a generalized eigenvalue problem. This problem is solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration of three and five-layered conical shells, made up of two different type of materials are considered. Parametric studies are made for analysing the frequencies of the shell with respect to the coefficients of thickness variations, length-to-radius ratio, length-to-thickness ratio and ply angles with different combination of the materials. The results are compared with the available data and new results are presented in terms of tables and graphs.
Viswanathan, K.K.,Kim, Kyung Su,Lee, Jang Hyun,Lee, Chang Hyun,Lee, Jae Beom Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6
Free axisymmetric vibrations of layered cylindrical shells of variable thickness are studied using spline function approximation techniques. Three different types of thickness variations are considered namely linear, exponential and sinusoidal. The equations of axisymmetric motion of layered cylindrical shells, on the longitudinal and transverse displacement components are obtained using Love's first approximation theory. A system of coupled differential equations on displacement functions are obtained by assuming the displacements in a separable form. Then the displacements are approximated using Bickley-spline approximation. The vibrations of two-layered cylindrical shells, made up of several types of layered materials and different boundary conditions are considered. Parametric studies have been made on the variation of frequency parameter with respect to the relative layer thickness, length ratio and type of thickness variation parameter.
K.K. Viswanathan,김경수,이장현,이창현,이재범 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6
Free axisymmetric vibrations of layered cylindrical shells of variable thickness are studied using spline function approximation techniques. Three different types of thickness variations are considered namely linear, exponential and sinusoidal. The equations of axisymmetric motion of layered cylindrical shells, on the longitudinal and transverse displacement components are obtained using Love’s first approximation theory. A system of coupled differential equations on displacement functions are obtained by assuming the displacements in a separable form. Then the displacements are approximated using Bickley-spline approximation. The vibrations of two-layered cylindrical shells, made up of several types of layered materials and different boundary conditions are considered. Parametric studies have been made on the variation of frequency parameter with respect to the relative layer thickness, length ratio and type of thickness variation parameter.
K. K.Viswanathan,김경수,이장현,고희성,이재범 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.11
The spline function technique is used to analyze the vibration of multi-layered circular cylindrical shells with crossply walls including first-order shear deformation theory. Both antisymmetric and symmetric cross-ply laminations are considered in this analysis. The governing equilibrium equations are obtained in terms of displacement and rotational functions. A system of coupled ordinary differential equations in terms of displacement and rotational functions are obtained by assuming the solution in a separable form. These functions are approximated by using Bickley-type splines of suitable order to obtain the generalized eigenvalue problem by applying point collocation techniques with appropriate boundary conditions. Parametric studies are performed to analyze the frequency response of the shell with reference to the material properties, number of layers, fiber orientation, thickness to radius ratio, length to radius ratio and circumferential node number. Reasonable agreement is found with existing results obtained by FEM and other methods. Valuable results are presented as graphs and discussed.