dc.contributor.author Kokkinos, Filis-Triantaphyllos T. en dc.date.accessioned 2014-03-14T21:09:26Z en dc.date.available 2014-03-14T21:09:26Z en dc.date.issued 1995-12-15 en dc.identifier.other etd-02132009-170805 en dc.identifier.uri http://hdl.handle.net/10919/37340 en dc.description.abstract A hybrid method is presented for the analysis of layers, plates, and multi-layered systems consisting of isotropic and linear elastic materials. The problem is formulated for the general case of a multi-layered system using a total potential energy formulation and employing the layerwise laminate theory of Reddy. A one-dimensional finite element model is used for the analysis of the multi-layered system through its thickness, and integral Fourier transforms are used to obtain the exact solution for the in-plane problem. Explicit expressions are obtained for the fundamental solution of the typical infinite layer, which are applied in the two-dimensional boundary integral equation model to produce the integral representation of the solution. The boundary integral equation model is two-dimensional, displacement-based and assumes piecewise continuous distribution of the displacement components through the system's thickness. The developed model describes the three-dimensional displacement field, the stress field, the strains and the interlaminar stresses over the entire domain of the problem as continuous functions of the position. This detailed three-dimensional analysis is achieved by incorporating only contour integrals. The boundary integral equations are discretized using the boundary element method and a numerical model is developed for the single numerical layer (element). This model is extended to the case of a multilayered system by introducing appropriate continuity conditions at the interfaces between the layers (firmly bonded layers, or separation, slip and friction between the layers). Assembly of the element matrices yields the global system of equations, which can be solved via iterative techniques. In addition, numerical techniques are developed for the evaluation of the boundary and domain integrals involved in the construction of the element matrices. The singular boundary integrals are computed using a special coordinate transformation, along with a subdivision of the boundary element and a transformation of the Gauss points. The domain integrals (regular, singular or near-singular) are transformed to regular definite integrals along the boundary through a semi-analytical approach. The proposed method provides a simple, efficient, and versatile model for a three-dimensional analysis of thick plates or multilayered systems. It can also be used to study plates resting on elastic foundations or plates with internal supports. The proposed method can be applied in an obvious manner to anisotropic materials and vibration problems. en dc.format.extent xi, 177 leaves en dc.format.medium BTD en dc.format.mimetype application/pdf en dc.language.iso en en dc.publisher Virginia Tech en dc.relation.isformatof OCLC# 34647247 en dc.relation.haspart LD5655.V856_1995.K71.pdf en dc.rights In Copyright en dc.rights.uri http://rightsstatements.org/vocab/InC/1.0/ en dc.subject finite element models en dc.subject fundamental solutions en dc.subject thick plates en dc.subject laminated plates en dc.subject sandwich plates en dc.subject layerwise theory en dc.subject boundary element models en dc.subject BEM and FEM coupling en dc.subject.lcc LD5655.V856 1995.K71 en dc.title Three-dimensional layerwise modeling of layered media with boundary integral equations en dc.type Dissertation en dc.contributor.department Engineering Mechanics en dc.description.degree Ph. D. en thesis.degree.name Ph. D. en thesis.degree.level doctoral en thesis.degree.grantor Virginia Polytechnic Institute and State University en thesis.degree.discipline Engineering Mechanics en dc.contributor.committeechair Reddy, Junuthula N. en dc.contributor.committeemember Griffin, Odis Hayden Jr. en dc.contributor.committeemember Hendricks, Scott L. en dc.contributor.committeemember Ragab, Saad A. en dc.contributor.committeemember Renardy, Yuriko Y. en dc.contributor.committeemember Katsikadelis, J. T. en dc.type.dcmitype Text en dc.identifier.sourceurl http://scholar.lib.vt.edu/theses/available/etd-02132009-170805/ en dc.date.sdate 2009-02-13 en dc.date.rdate 2009-02-13 en dc.date.adate 2009-02-13 en
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