The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Marek-jerzy Pindera - One of the best experts on this subject based on the ideXlab platform.
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Local/global stiffness Matrix Formulation for composite materials and structures
Composites Engineering, 1991Co-Authors: Marek-jerzy PinderaAbstract:Abstract An efficient algorithm is outlined for solving boundary-value problems involving laminated composite materials and structures that require satisfaction of both continuity of tractions and displacements along common interfaces. The method is based on the systematic construction of a global stiffness Matrix for the entire laminated structure in terms of local stiffness matrices of the individual layers. The local stiffness Matrix relates the traction components at the upper and lower (or inner and outer) surface of a given layer to the corresponding displacements. The assembly of local stiffness matrices into a global stiffness Matrix is carried out by enforcing continuity conditions along the interfaces which, in effect, leads to reFormulation of the problem in terms of interfacial displacements as the basic unknown variables. This, in turn, results in the elimination of certain redundant continuity conditions and thus reduction in the number of simultaneous algebraic equations that need to be solved. An additional advantage of the local/global stiffness Matrix Formulation is the ease with which certain mixed boundary-value problems can be reduced to singular integral equations of the Fredholm type for the determination of unknown quantities such as the contact pressure in the case of contact problems and the crack-opening displacement in the case of interfacial crack problems.
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local global stiffness Matrix Formulation for composite materials and structures
Composites Engineering, 1991Co-Authors: Marek-jerzy PinderaAbstract:Abstract An efficient algorithm is outlined for solving boundary-value problems involving laminated composite materials and structures that require satisfaction of both continuity of tractions and displacements along common interfaces. The method is based on the systematic construction of a global stiffness Matrix for the entire laminated structure in terms of local stiffness matrices of the individual layers. The local stiffness Matrix relates the traction components at the upper and lower (or inner and outer) surface of a given layer to the corresponding displacements. The assembly of local stiffness matrices into a global stiffness Matrix is carried out by enforcing continuity conditions along the interfaces which, in effect, leads to reFormulation of the problem in terms of interfacial displacements as the basic unknown variables. This, in turn, results in the elimination of certain redundant continuity conditions and thus reduction in the number of simultaneous algebraic equations that need to be solved. An additional advantage of the local/global stiffness Matrix Formulation is the ease with which certain mixed boundary-value problems can be reduced to singular integral equations of the Fredholm type for the determination of unknown quantities such as the contact pressure in the case of contact problems and the crack-opening displacement in the case of interfacial crack problems.
Jeremiah Brackbill - One of the best experts on this subject based on the ideXlab platform.
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Mass Matrix Formulation of the FLIP particle-in-cell method
Journal of Computational Physics, 1992Co-Authors: D. Burgess, Deborah Sulsky, Jeremiah BrackbillAbstract:A refinement of FLIP [Brackbill and Ruppel, J. Comput. Phys. 65, 314 (1986)] is described which uses a mass Matrix Formulation to achieve greater accuracy and less numerical diffusion over the previous version. Without the refinement, there is a significant dissipation of energy in modeling elastic vibrations of a solid. Moreover, in modeling an initial flow discontinuity there are sub-grid-scale oscillations in the particle velocity field in the neighborhood of the discontinuity. These difficulties are eliminated using the mass Matrix. In addition, the mass Matrix Formulation conserves kinetic energy, linear and angular momentum, and is Galilean invariant.
Peter E. Latham - One of the best experts on this subject based on the ideXlab platform.
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The scattering Matrix Formulation for overmoded coaxial cavities
IEEE Transactions on Microwave Theory and Techniques, 1992Co-Authors: W. Lawson, Peter E. LathamAbstract:The scattering Matrix Formulation for complex right-circular activities is extended to coaxial circuits with variable inner radii. The modified eigenvectors, which include the TEM wave, and the modified boundary conditions are presented. The properties of several configurations are examined and transmission measurements are shown to be in good agreement with theory. >
Kara Peters - One of the best experts on this subject based on the ideXlab platform.
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Modified transfer Matrix Formulation for bragg grating strain sensors
Journal of Lightwave Technology, 2004Co-Authors: Mohanraj Prabhugoud, Kara PetersAbstract:This paper presents a Formulation for the application of the transfer Matrix method to Bragg grating strain sensors. A modified T-Matrix representation is detailed for the sensor problem based on an effective period derived from the coupling coefficients. This modified T-Matrix Formulation is shown to converge to the coupled-mode equations solution for a large number of grating segments, even in the presence of significant strain gradients. Several numerical examples are presented to demonstrate the importance of inclusion of the strain gradient in the calculation. In addition, the current Formulation is validated by application to previously published experimental data.
George W. Kattawar - One of the best experts on this subject based on the ideXlab platform.
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On the far field in the Lorenz–Mie theory and T-Matrix Formulation
Journal of Quantitative Spectroscopy and Radiative Transfer, 2010Co-Authors: Ping Yang, George W. KattawarAbstract:Abstract The far field within the context of the Lorenz–Mie theory and the T-Matrix Formulation is usually expressed on the basis of the asymptotic properties of vector spherical waves. The radiation condition is taken into account by employing proper vector spherical functions as the expansion basis of the scattered field. The asymptotic behavior of the Hankel function is obtained from differential equations. The asymptotic far field can also be obtained from the Kirchhoff surface integral equation, in which the radiation condition has been implemented when it is derived from the Maxwell equations. This note is to present an explicit establishment of the relationship between the asymptotic far field and the near field in the Lorenz–Mie theory and the T-Matrix Formulation through the Kirchhoff surface integral.