In this Thesis, the problem of the Free Vibrations Analysis of Doubly Stiffened Composite, Orthotropic and/or Isotropic, Base Plates or Panels (with Orthotropic Stiffening Plate Strips) is investigated. The composite plate or panel system is made of an Orthotropic and/or Isotropic Base Plate stiffened or reinforced by adhesively bonded Upper and Lower Orthotropic Stiffening Plate Strips. The plates are assumed to be the Mindlin Plates connected by relatively very thin adhesive layers. The general problem under study is considered in terms of three problems, namely Main PROBLEM I Main PROBLEM II and Main PROBLEM III. The theoretical formulation of the Main PROBLEMS is based on a First Order Shear Deformation Plate Theory (FSDPT) that is, in this case, the Mindlin Plate Theory. The entire composite system is assumed to have simple supports along the two opposite edges so that the Classical Levy&#039 / s Solutions can be applied in that direction. Thus, the transverse shear deformations and the rotary moments of inertia of plates are included in the formulation. The very thin, yet elastic deformable adhesive layers are considered as continua with transverse normal and shear stresses. The damping effects in the plates and the adhesive layers are neglected. The sets of the systems of equations of the Mindlin Plate Theory are reduced to a set of the Governing System of First Order Ordinary Differential Equations in the state vector form. The sets of the Governing System for each Main PROBLEM constitute a Two-Point Boundary Value Problem in the y-direction which is taken along the length of the plates. Then, the system is solved by the Modified Transfer Matrix Method (with Interpolation Polynomials and/or Chebyshev Polynomials)which is a relatively semi-analytical and numerical technique. The numerical results and important parametric studies of the natural modes and the corresponding frequencies of the composite system are presented.

Elastic layers bonded to reinforcing sheets are widely used in many engineering applications, e.g., as elastic foundations to machinery, as seismic isolators to structures, etc. Because of its practical importance, the behavior of bonded elastic layers under some basic deformation modes (e.g., compression, bending and shear modes) has attracted the attention of many researchers. However, the analytical works available in literature involve, with the object of obtaining design formulas, many simplifying assumptions. In this dissertation, a new formulation is developed for the analysis of bonded elastic layers, which removes most of the assumptions used in the earlier formulations. Since the displacement boundary conditions are included in the formulation itself, there is no need to start the formulation with some assumptions on stress and/or displacement distributions or with some limitations on geometrical and/or material properties. For this reason, the solutions derived from this formulation are valid not only for &ldquo / thin&rdquo / layers of strictly/nearly incompressible materials but also for &ldquo / thick&rdquo / layers and/or compressible materials. The advanced solutions obtained within the framework of the new formulation are used to study the behavior of bonded elastic layers under basic deformation modes. The effects of three key parameters, shape factor, Poisson&rsquo / s ratio and reinforcement flexibility, on effective layer moduli, displacement/stress distributions, and location/magnitude of maximum stresses are investigated. It is shown that the stress assumptions of the &ldquo / pressure&rdquo / method are inconsistent with the results obtained for thick layers and/or compressible materials and/or flexible reinforcements, and that the assumption &ldquo / plane sections remain plane&rdquo / is not valid, in general.

The Poiseuille Flow is the flow of a viscous incompressible fluid in a channel between two infinite parallel plates. The behaviour of flow is properly described by the well-known Navier-Stokes Equations. The fact that Navier-Stokes equations are partial differential equations makes their solution difficult. They can rarely be solved in closed form. On the other hand, numerical techniques can be applied successfully to the well-posed partial differential equations. In the present study pseudo-spectral method is implemented to analyze the Poiseuille Flow. The pseudo-spectral method is a high-accuracy numerical modelling technique. It is an optimum choice for the Poiseuille flow analysis due to the flows simple geometry. The method makes use of Fourier Transform and by handling operations in the Fourier space reduces the difficulty in the solution. Fewer terms are required in a pseudo-spectral orthogonal expansion to achieve the same accuracy as a lower order method. Karhunen-Lo&egrave / ve (KL) decomposition is widely used in computational fluid dynamics to achieve reduced storage requirements or construction of relatively low-dimensional models. In this study the KL basis is extracted from the flow field obtained from the direct numerical simulation of the Poiseuille flow.

This study presents the investigation and the verification of the modal parameters of a plate-like structure by using different modal analysis methods. A fin-like structure which is generally used in aircraft is selected as a subcategory of a plate-like test structure. In the first part of the thesis, the natural frequencies and the corresponding mode shapes of the fin are extracted by Finite Element Analysis method. Classical Modal Analysis and Testing methods comprising both impact hammer and modal shaker applications are then applied in order to obtain the modal parameters such as / resonance frequencies, mode shapes and damping ratios. In the second part, a recent modal analysis technique, Operational Modal Analysis, is also applied in the laboratory environment. Since Operational Modal Analysis method does not require any information of input forcing, the fin structure is tested under both mechanical and acoustical types of excitations without measuring the given input forces. Finally, Operational Modal Analysis and Testing is also performed under various flow conditions generated in the wind tunnel which may simulate the real operating environment for the fin structure. The modal parameters extracted under these flow conditions are then compared with the previously obtained Finite Element, Classical and Operational Modal Analyses results.

In this thesis, the free vibration analysis of anisotropic laminated composite shells of revolution (ALCSOR) is studied. The governing equations are kinematic, constitutive, and motion equations. Geometrically linear strain-displacement equations of Reissner-Naghdi shell theory in combination with first-order shear deformation theory in which transverse shear and rotatory inertia effects are taken into consideration. The constitutive relations are for macrosopically ALCSOR in which statically equivalent force and moment resultants, instead of internal stresses for a single layer, are introduced. Equations of motion for the free vibration problem are obtained by the Hamilton&amp / #8217 / s principle. The derived governing equations for the free vibration analysis of ALCSOR are initially formulated into a system of partial differential equations in terms of fundamental variables. Then, those partial differential equations are reduced to a system of first order ordinary differential equations by applying finite exponential Fourier Transform method resulting in a two point boundary value problem. It has been demonstrated that the application of the finite exponential Fourier transform made it possible to solve the governing equations, comprising the full anisotropic form of the constitutive equations, which was otherwise impossible to solve with the classical Fourier decomposition method. First, the boundary value problem formulated is reduced to a series of initial value problems, then the multisegment numerical integration is used in combination with the frequency trial method in order to find the critical modes within a given range of natural frequencies. A computer code DALSOR is written for the solution of the natural frequencies and mode shapes of mascroscopically ALCSOR. DALSOR is applicable to any general boundary condition at both ends of the shell, and allows for variation of all elastic and geometric properties in the meridional direction. Numerical results are presented, and mainly discussions on the method of solution and the effect of macroscopic anisotropy on modal characteristics, mainly natural frequencies, are made. Various case studies are performed primarily on cylindrical shells in order to investigate the effects of mainly fiber orientation angle, stacking sequence, arbitrary boundary conditions at the edges of the shell, thickness-to-radius ratio on the modal characteristics, mainly natural frequencies. Application of the method of solution has also been demonstrated for a truncated composite spherical shell.

In my diploma work I concentrated on various forms of work with foster-families focused on prevention, consultancy and special help. Regional authorities are obliged to arrange them as a part of so-called consultations on foster care practice according to para. 4 of section 11 of Act No.359/1999 Coll. on Social and Legal protection of children. I tried to map the way the particular regional authorities fill this paragraph. In more detail I attended to activity of south-bohemian regional authority in this field. In terms of the research I found that the importance of foster-families meetings consists in experience exchange, feeling of sharing and gaining new information. From that point of view more days meetings are the most popular with both fosterers and social workers when there is more time for it.

This dissertation examines the different interpretations of the secondary sources for Alexander the Great by three modern historians, Nicholas Hammond, Peter Green and Mary Renault. The Introduction looks briefly at the lost primary Alexander-histories, the extant works of Diodorus Siculus, Quintus Curtius, Plutarch and Arrian and includes an abbreviated curriculum vltae of each modern author. Chapter X concerns modern interpretations of the controversial circumstances surrounding the accession of Alexander and the assassination of Philip. Chapter II covers the elimination of possible rivals, Attalus, Alexander Lyncestes and Amyntas son of Perdiccas, two major conspiracies - the Philotas Affair and the death of Parmenio, the conspiracy of the Royal Pages and death of Callisthenes - and the killing of Cleitus the Black. Chapter III deals with modern explanations of the death of Alexander. The Conclusion highlights significant theories and trends presented by the modern historians, which influence their interpretations of the ancient sources. / History / M.A. (Ancient History)

This dissertation examines the different interpretations of the secondary sources for Alexander the Great by three modern historians, Nicholas Hammond, Peter Green and Mary Renault. The Introduction looks briefly at the lost primary Alexander-histories, the extant works of Diodorus Siculus, Quintus Curtius, Plutarch and Arrian and includes an abbreviated curriculum vltae of each modern author. Chapter X concerns modern interpretations of the controversial circumstances surrounding the accession of Alexander and the assassination of Philip. Chapter II covers the elimination of possible rivals, Attalus, Alexander Lyncestes and Amyntas son of Perdiccas, two major conspiracies - the Philotas Affair and the death of Parmenio, the conspiracy of the Royal Pages and death of Callisthenes - and the killing of Cleitus the Black. Chapter III deals with modern explanations of the death of Alexander. The Conclusion highlights significant theories and trends presented by the modern historians, which influence their interpretations of the ancient sources. / History / M.A. (Ancient History)