Dissertations / Theses: 'Finite elements analysis'

1

Karaolani, Persephoni. "Finite elements for image analysis." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240203.

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Monaghan, Dermot James. "Automatically coupling elements of dissimilar dimension in finite element analysis." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326293.

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Berger, Stephanie 1981. "Experimental and finite element analysis of high pressure packer elements." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28879.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004.
Includes bibliographical references (leaf 30).
Packer elements are traditionally rubber seals that can operate under specified downhole conditions and provide a seal for either a short-term, retrievable, or a long-term, permanent, completion. In this case a retrievable 19.7cm (7-3/4") packer element for a high-pressure high-temperature (HPHT) environment was designed and tested. The element created a seal between the mandrel, or tubing, and the casing. At high temperature and pressure rubber needs to be contained so that it will create and maintain an energized seal. In this study only Aflas rubber was tested. Various backup systems were examined; some more traditional designs such as the carbon steel foldback ring were compared to more experimental ideas. Results of theoretical simulations were compared to actual test results in order to gain a greater understanding of element behavior. Experiments were also performed to study the process of element setting, which is difficult to observe due to the high pressures and temperatures required. In a related study alternative materials to rubber such as annealed high-conductivity oxygen-free copper were tested to determine if the properties could be applied for packer element applications. The most successful design was the foldback ring with an anti-extrusion PEEK ring under the gage ring. This design passed a liquid test at 134 MPa (19.5k psi) differential pressure and a gas test at 87.6 MPa (12.7k psi) differential pressure. New designs such as the split ring with mesh and the garter spring with mesh did not pass fixture tests but could be successful with further modifications. FEA was used as an analytical tool to create simulations of the element after a setting force is applied. The modeling was shown to correlate to the actual test results and therefore it would be a good tool to use in future studies.
by Stephanie Berger.
S.M.

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4

Bendickson, Jon M. "Analysis of finite diffractive optical elements." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15424.

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Tseng, Gordon Bae-Ji. "Investigation of tetrahedron elements using automatic meshing in finite element analysis /." Online version of thesis, 1992. http://hdl.handle.net/1850/10699.

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Lai, Zhi Cheng. "Finite element analysis of electrostatic coupled systems using geometrically nonlinear mixed assumed stress finite elements." Diss., Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-05052008-101337/.

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7

Foo, Senglee. "Finline discontinuity analysis using vectorial finite elements." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39311.

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In this thesis, a numerically efficient three-dimensional finite element scheme is used to analyze arbitrarily-shaped discontinuities in inhomogeneous-dielectric-loaded waveguides. Special emphasis is placed on discontinuity problems in finlines and related structures. A simple but accurate recursive algorithm, the boundary-marching method, for modeling uniform waveguides of arbitrarily-shaped cross-section is developed for the analysis. This algorithm is used to generate the matrix representations of various waveguides, including the unilateral finlines. It is shown that, by using the substructure formulation and the matrix representation of the uniform guide, the finite element mesh of the discontinuity problem can be truncated to a proximity very close to the discontinuity without compromising with the result accuracy. Finally, characteristics of inductive strips in unilateral finline are evaluated using the finite element scheme. The scattering parameters of the inductive strips obtained with the finite element method agree with published measurements and other numerical solutions to within a few percent with a relatively small number of elements. Various effects of the manufacturing process, such as the effect of mounting grooves, finite metalization thickness and deflection of dielectric substrate, on the discontinuity parameters are studied in detail using the finite element scheme.

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Shorter, Philip. "Combining finite elements and statistical energy analysis /." Online version, 1998. http://bibpurl.oclc.org/web/23511.

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9

毛生根 and Shenggen Mao. "Symplectic analysis of flexible structures by finite elements." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B3123754X.

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Mao, Shenggen. "Symplectic analysis of flexible structures by finite elements /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19471154.

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Nyaoro, Dalmas Lucas. "Analysis of soil-structure interaction by finite elements." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/8675.

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Onisiphorou, Christakis. "Stochastic analysis of saturated soils using finite elements." Thesis, University of Manchester, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488082.

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This thesis has investigated the static liquefaction failure, during construction, of the Nerlerk underwater berm. This hydraulically-placed sandfill structure was designed to form part of an artificial caisson island, intended for use as a year-round exploration drilling platform in the Canadian Beaufort Sea. The aim of the investigation has been to examine how liquefaction was possible in a fill which, according to CPT data, was predominantly dilative; in particular, to study the influence, on stability, of 'pockets' of liquefiable material in the sandfill. Instead of a conventional deterministic approach, based on mean strengths, a stochastic type of approach has been necessary, in order to accurately model material heterogeneity. For this research, the double-hardening constitutive model Monot has been used, this being capable of modelling a wide range of material behaviour, from liquefiable to strongly dilative. The material parameters have been calibrated from an extensive laboratory database and expressed in terms of density via the state parameter for sands. The state parameter statistics have been derived, based on a detailed statistical evaluation of an extensive CPT database from the Tarsiut and Nerlerk island sites. These statistics were used for generating uni-variate random fields of state parameter, from which the Monot material parameters could then be backfigured, in order to model the spatial variability in the fill (i.e. heterogeneity). A number of sophisticated stochastic investigations have been performed, using an advanced two-dimensional finite element algorithm encompassing Monot. The results have shown that liquefaction of the Nerlerk berm is consistent with CPT data: i.e. it may be possible for a predominantly dilative fill to liquefy, under static loading conditions, due to the presence of semi-continuous loose zones arising from deposition-induced anisotropy. For such problems, in which material anisotropy is present, a deterministic approach is not appropriate and can be misleading, as this was shown to represent an upper bound response to the stochastic simulations.

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Bakhtiari, Siamak. "Stochastic finite element slope stability analysis." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/stochastic-finite-element-slope-stability-analysis(c1b451d9-8bf6-43ff-9c10-7b5209fb45c1).html.

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In this thesis, the failures that occurred during the construction of the Jamuna Bridge Abutment in Bangladesh have been investigated. In particular, the influence of heterogeneity on slope stability has been studied using statistical methods, random field theory and the finite element method. The research is divided into three main parts: the statistical characterization of the Jamuna River Sand, based on an extensive in-situ and laboratory database available for the site; calibration of the laboratory data against a double-hardening elastoplastic soil model; and stochastic finite element slope stability analyses, using a Monte Carlo simulation, to analyse the slope failures accounting for heterogeneity. The sand state has been characterised in terms of state parameter, a meaningful quantity which can fully represent the mechanical behaviour of the soil. It was found that the site consists of predominantly loose to mildly dilative material and is very variable. Also, a Normal distribution was found to best represent the state parameter and a Lognormal distribution was found to best represent the tip resistance.The calibration of the constitutive model parameters was found to be challenging, as alternative approaches had to be adopted due to lack of appropriate test results available for the site. Single-variate random fields of state parameter were then linked to the constitutive model parameters based on the relationships found between them, and a parametric study of the abutment was then carried out by linking finite elements and random field theory within a Monte Carlo framework.It was found that, as the degree of anisotropy of the heterogeneity increases, the range of structural responses increases as well. For the isotropic cases, the range of responses was relatively smaller and tended to result in more localised failures. For the anisotropic cases, it was found that there are two different types of deformation mechanism. It was also found that, as the vertical scale of fluctuation becomes bigger, the range of possible structural responses increases and failure is more likely. Finally, it was found that the failed zones observed during the excavation of the West Guide Bund of the Jamuna Bridge Abutment could be closely predicted if heterogeneity was considered in the finite element analyses. In particular, it was found that, for such a natural deposit, a large degree of anisotropy (in the range of 20) could account for the deformation mechanisms observed on site.

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Iosilevich, Alexander G. "An analysis of finite elements for plate bending problems." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38152.

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Warren, Gregory S. "The analysis of numerical dispersion in the finite-element method using nodal and tangential-vector elements." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/13271.

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He, Xiaoming. "Bilinear Immersed Finite Elements For Interface Problems." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/27819.

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In this dissertation we discuss bilinear immersed finite elements (IFE) for solving interface problems. The related research works can be categorized into three aspects: (1) the construction of the bilinear immersed finite element spaces; (2) numerical methods based on these IFE spaces for solving interface problems; and (3) the corresponding error analysis. All of these together form a solid foundation for the bilinear IFEs. The research on immersed finite elements is motivated by many real world applications, in which a simulation domain is often formed by several materials separated from each other by curves or surfaces while a mesh independent of interface instead of a body-fitting mesh is preferred. The bilinear IFE spaces are nonconforming finite element spaces and the mesh can be independent of interface. The error estimates for the interpolation of a Sobolev function in a bilinear IFE space indicate that this space has the usual approximation capability expected from bilinear polynomials, which is O(h²) in L² norm and O(h) in H¹ norm. Then the immersed spaces are applied in Galerkin, finite volume element (FVE) and discontinuous Galerkin (DG) methods for solving interface problems. Numerical examples show that these methods based on the bilinear IFE spaces have the same optimal convergence rates as those based on the standard bilinear finite element for solutions with certain smoothness. For the symmetric selective immersed discontinuous Galerkin method based on bilinear IFE, we have established its optimal convergence rate. For the Galerkin method based on bilinear IFE, we have also established its convergence. One of the important advantages of the discontinuous Galerkin method is its flexibility for both p and h mesh refinement. Because IFEs can use a mesh independent of interface, such as a structured mesh, the combination of a DG method and IFEs allows a flexible adaptive mesh independent of interface to be used for solving interface problems. That is, a mesh independent of interface can be refined wherever needed, such as around the interface and the singular source. We also develop an efficient selective immersed discontinuous Galerkin method. It uses the sophisticated discontinuous Galerkin formulation only around the locations needed, but uses the simpler Galerkin formulation everywhere else. This selective formulation leads to an algebraic system with far less unknowns than the immersed DG method without scarifying the accuracy; hence it is far more efficient than the conventional discontinuous Galerkin formulations.
Ph. D.

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17

Silveira, André Rodrigues Garcia da. "Determinação analítica da correção de hélice em um par engrenado devido ao efeito da flexo-torção." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3151/tde-23062016-112942/.

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O foco do presente trabalho é estudar a intensificação da pressão de contato entre os dentes de duas engrenagens cilíndricas de dentes retos, que ocorre por causa do deslocamento dos componentes de um redutor de velocidades. Essa intensificação ocorre inclusive em um redutor fabricado sem quaisquer erros de usinagem ou de montagem. A correção de hélice é uma usinagem realizada na superfície do dente da engrenagem que compensa os deslocamentos dos eixos e engrenagens, devido à flexão e à torção, e os deslocamentos dos dentes das engrenagens, devido à flexão e à pressão de contato. Foram estudados efeitos importantes para essa correção de hélice em um redutor de velocidades. Com isso, foi desenvolvido um modelo analítico que calcula a correção necessária para diminuir esse intensificador de pressão de contato em função dos deslocamentos citados acima. Esse modelo analítico foi comparado com um modelo analítico da literatura e com o software comercial RIKOR®. Os resultados de correção de hélice propostos são similares aos da literatura e do RIKOR® com exceção das bordas das engrenagens, aonde existem algumas divergências. Posteriormente, foi desenvolvido um modelo sólido de engrenagem com o perfil evolvente e com as correções de hélice calculadas analiticamente. Este modelo tridimensional (3D) foi elaborado usando os softwares SolidWorks® e Inventor® e simulado por elementos finitos por meio do software ANSYS®. Verificou-se que as três correções de hélice - a proposta, a da literatura e a do RIKOR® - realmente diminuem a intensificação de pressão de contato no flanco do dente da engrenagem. Por fim, foi possível visualizar que a correção proposta nesta dissertação é 3% mais efetiva que a proposta pela literatura e pelo RIKOR® para o caso analisado.
This work will study the contact pressure intensifier between two spur gears teeth, which exists due to the displacement of the components of the gearbox. This effect occurs even in gearboxes manufactured without any machining and/or assembling errors. The lead correction is a machining operation conducted at the gear tooth surface that compensates the displacement of shafts and gears, due to bending and torsion, and the gear teeth displacement, due to bending and contact pressure. Factors that are important to the lead correction in gearboxes were studied. An analytical model was proposed in order to evaluate the lead correction necessary to diminish the contact pressure intensifier as a function of the displacements mentioned above. This analytical model was compared to a literature one and to the commercial software RIKOR®. The results of the proposed lead correction are similar to the literature and RIKOR® ones, although there are differences at the borders of the gears. This work also describes the development of a solid model of the gears and shafts with the involute profile and the lead correction evaluated analytically. This model is tridimensional (3D) and was designed using SolidWorks® and Inventor software. It was simulated using finite element analysis software ANSYS® and it was possible to verify that the three lead corrections - proposed, from literature and from RIKOR® - diminished the contact pressure intensifier at the gears tooth flank. It was also possible to verify that the lead correction proposed is 3% more effective than the other ones for the case analyzed.

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18

鍾偉昌 and Wai-cheong Chung. "Geometrically nonlinear analysis of plates using higher order finite elements." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B31207601.

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19

Mian, M. Abid. "Application of finite elements to stress analysis of laminated plates." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282789.

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Chung, Wai-cheong. "Geometrically nonlinear analysis of plates using higher order finite elements /." [Hong Kong : University of Hong Kong], 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12225022.

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Cho, Seong Wook. "On mixed-interpolated general shell finite elements for nonlinear analysis." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/60728.

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22

Madapur, Uma. "Integrated structural analysis and design using 3-D finite elements." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43407.

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When structural analysis is performed via iterative solution technique it is possible to integrate the analysis and design iterations in an integrated analysis and design procedure. The present work seeks to apply an integrated analysis and design approach due to Rizk to the problem of hole shape optimization in thick plates.

The plates are modeled by three dimensional eight noded elements. An element by element (EBE) preconditioned conjugate gradient (PCG) method is used for the structural analysis, because this method is well suited for poorly banded three dimensional problems. The plates were optimized so as to minimize the stress concentration near the hole measured by the ratio of the Von Mises stress to the applied boundary stress. The analysis program was validated by comparision to a commercial finite-element program as well as photoelastically obtained stress concentrations. Similarly, the optinlization procedure was checked against plates optimized by a photoelastic technique. Good agreement was observed.

The integrated analysis and design approach tested here is based on partially converged solutions of the EBE-PCG iterative process. A study of the effect of the number of iterations on analysis and derivative accuracy was performed. Based on this analysis a choice was made for the number of iterations to be used in the integrated analysis and design procedure. It was found that the cost of the design could be significantly reduced with only minimal effects on the final shape and stress concentration factor.

Master of Science

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23

Savage, Joe Scott. "Vector finite elements for the solution of Maxwell's equations." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/13901.

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Grizatouline, Vadim D. "Mathematical modelling of piezo active elements." Thesis, De Montfort University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391854.

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25

Hauber, Robert J. "Finite element analysis of an integrally molded fiber reinforced polymer bridge." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321369004.

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Charkas, Hasan Farouk. "Devising smart finite elements for adaptive analysis of inverse structural problems /." Search for this dissertation online, 2005. http://wwwlib.umi.com/cr/ksu/main.

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Iu, Vai-pan, and 姚偉彬. "Nonlinear vibration analysis of multilayer sandwich structure by incremental finite elements." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1985. http://hub.hku.hk/bib/B31230623.

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Bouzeghoub, M. C. "Investigation and implementation of hybrid finite elements for plane stress analysis." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/804426/.

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Iu, Vai-pan. "Nonlinear vibration analysis of multilayer sandwich structure by incremental finite elements /." [Hong Kong : University of Hong Kong], 1985. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12322945.

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SANTANA, WLASMIR CAVALCANTI DE. "H-ADAPTATIVE FINITE ELEMENTS IN THE ANALYSIS OF PLANE ELASTIC PROBLEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1993. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24913@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Apresenta-se neste trabalho a implementação de um método adaptativo de refinamento automático de malhas de Elementos de Finitos. O método aplica-se a problemas planos de elasticidade linear. Elementos triangulares e quadrilaterais (lineares e quadráticos) são utilizados. Estimativas de erro a-posteriori são obtidas através do estimador de erro proposto por Zienkiewicz-Zhu, empregando-se uma técnica de recuperação da solução numérica fornecida pelo MEF (superconvergent patch recovery technique). A metodologia da adaptação da malha emprega o conceito de remalhamento do domínio na forma proposta por Peraire e Zhu para malhas de elementos triangulares e quadrilaterais, respectivamente. Implementa-se um esquema de localização de singularidades presentes no domínio baseado no conceito de concentração da energia de deformação. O uso deste esquema combinado com a metodologia de adaptação permite um processo automático sem intervenção do usuário durante os ciclos de refinamento da malha. Para demonstrar-se a performance do método são analisados três problemas: uma viga curta em balanço sob carregamento distribuído, uma placa quadrada com furo quadrado e uma placa quadrada com dupla trinca.
This work presentes the theory and the implementation techniques for na automatic h-adaptive procedure of finite elemento mesh refinements. Themetodology is applied to plane problems inlinear elasticity using triangular and quadrilateral shape elements with linear and quadratic lagrangian interpolation functions. Solution errors are a-posteriori evaluated using the Zienkiewicz- Zhu error estimator based on numerical solutions recovered from the finite element method solution – superconvergent patch recovery technique. For the mesh adaptivity of triangular and quadrilateral elements the remeshing concepts proposed by. Peraire and Zhu employed, respectively. The presence of solution singularities and their intensity is identified throughout the finite cloment mesh from the evaluation of the strain energy concentration, considering the numerical solution obtained. This scheme combined with adaptivity methodology allows for fully automatic procedure of mesh refinement/derefinement at the cycle of solution searching. Three examples are considered to demonstrate the procedure ability in handling elasticity problems: a cantiliver short beam under transverse distributed loading, a square plate with a middle square hole under inplace traction distributed loading and a double notch square plate under in plane distributed loading.

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Attanayake, Champike. "Finite Elements and Practical Error Analysis of Huxley and EFK Equations." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1215437536.

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Pennington, Derek Steven. "Nonlinear heat transfer and thermo mechanical stress analysis using finite elements." Master's thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/7602.

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This thesis deals with the development, implementation and testing of numerical procedures for the heat transfer and thermo-mechanical analysis of sol id continua. Steady state conduction heat transfer is developed as a particular case of the general field equation. Internal heat generation and the boundary conditions of specified temperatures, flux, convection. and radiation are included. The stress - strain - temperature relationships for a corresponding body are not coupled to the heat transfer relationships for steady state conditions. The heat transfer problem is thus solved prior to, and independently of, the mechanical problem. The resulting temperature field is adopted for the solution of the thermal deformation problem. Finite element formulations using a common discretization are developed for these problems using Galerkin' s method. The formulations are implemented in an existing temperature independent nonlinear finite element stress analysis code. Four, eight and nine noded isoparametric continuum finite elements with the option of the plane stress, plane strain and axisymetric cases are utilized. Nonlinear heat transfer due to temperature dependent thermal conductivity and/or internal heat generation is solved using an iterative method based on the Newton-Raphson algorithm. Thermal deformations and stresses are determined by calculating equivalent nodal loads corresponding to the thermal strains which result from the temperature field. These are then applied to the mechanical model. The implementation is illustrated by three examples whose solutions compare favourably with analytical solutions taken from the literature.

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Lim, Lian Hoon. "Transient analysis of cage induction machines using time-stepping finite elements." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/8781.

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Sugimoto, Rie. "Special wave finite and infinite elements for the solution of the Helmholtz equation." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/3142/.

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The theory and the formulation of the special wave finite elements are discussed, and the special integration schemes for the elements are developed. Then the special wave infinite elements, a new concept of the mapped wave infinite elements with multiple wave directions, are developed. Computational models using these elements coupled together are tested by the applications of wave problems. In the special wave finite elements, the potential at each node is expanded in a discrete series of approximating plane waves propagating in different directions. Because of this a single element can contain many wavelengths, unlike the standard finite elements. This is a great advantage in the reduction of the degree of freedom of the problem, however the computational cost of the numerical integration over an element becomes high due to the oscillatory shape functions. Therefore the special semi-analytical integration schemes for the special wave finite elements are developed. The schemes are independent of wavenumber and efficient for short waves problems. In many cases of wave problems, it is practical to consider the domain as being infinite. However the finite element method can not deal with infinite domains. Infinite elements are an extension of the concept of finite elements in which the element has an infinite extent in one or more directions to address this limitation. In the special wave infinite element developed in this study multiple waves propagating in different directions are considered, in contrast to conventional infinite elements in which only a single wave propagating in the radial direction is considered. The shape functions of the special wave infinite elements contain trigonometric functions to describe multiple waves, and the amplitude decay factor to satisfy the radiation condition. The special wave infinite elements become a straightforward extension to the special wave finite elements for wave problems in an unbounded domain.

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Park, Gi-Ho. "p-Refinement Techniques for Vector Finite Elements in Electromagnetics." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/10602.

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The vector finite element method has gained great attention since overcoming the deficiencies incurred by the scalar basis functions for the vector Helmholtz equation. Most implementations of vector FEM have been non-adaptive, where a mesh of the domain is generated entirely in advance and used with a constant degree polynomial basis to assign the degrees of freedom. To reduce the dependency on the users' expertise in analyzing problems with complicated boundary structures and material characteristics, and to speed up the FEM tool, the demand for adaptive FEM grows high. For efficient adaptive FEM, error estimators play an important role in assigning additional degrees of freedom. In this proposal study, hierarchical vector basis functions and four error estimators for p-refinement are investigated for electromagnetic applications.

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Ellis, Truman Everett. "High Order Finite Elements for Lagrangian Computational Fluid Dynamics." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/282.

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A general finite element method is presented to solve the Euler equations in a Lagrangian reference frame. This FEM framework allows for separate arbitrarily high order representation of kinematic and thermodynamic variables. An accompanying hydrodynamics code written in Matlab is presented as a test-bed to experiment with various basis function choices. A wide range of basis function pairs are postulated and a few choices are developed further, including the bi-quadratic Q2-Q1d and Q2-Q2d elements. These are compared with a corresponding pair of low order bi-linear elements, traditional Q1-Q0 and sub-zonal pressure Q1-Q1d. Several test problems are considered including static convergence tests, the acoustic wave hourglass test, the Sod shocktube, the Noh implosion problem, the Saltzman piston, and the Sedov explosion problem. High order methods are found to offer faster convergence properties, the ability to represent curved zones, sharper shock capturing, and reduced shock-mesh interaction. They also allow for the straightforward calculation of thermodynamic gradients (for multi-physics calculations) and second derivatives of velocity (for monotonic slope limiters), and are more computationally efficient. The issue of shock ringing remains unresolved, but the method of hyperviscosity has been identified as a promising means of addressing this. Overall, the curvilinear finite elements presented in this thesis show promise for integration in a full hydrodynamics code and warrant further consideration.

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Yu, John Junyao. "Dynamic analysis of rotor-bearing systems using three-dimensional solid finite elements." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23097.pdf.

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38

Giannopoulos, Vassileios S. "Progressive delamination analysis of layered composite plates using dimensionally reduced finite elements." Thesis, Cranfield University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397039.

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39

Alon, Yair. "Analysis of thick composite plates using higher order three dimensional finite elements." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA243188.

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Thesis (M.S. in Aeronautical Engineering and Aeronautics and Astronautics Engineers Degree)--Naval Postgraduate School, December 1990.
Thesis Advisor(s): Kolar, Ramesh. Second Reader: Lindsey, G. H. "December 1990." Description based on title screen as viewed on March 30, 2010. DTIC Descriptor(s): Thickness, stability, composite materials, laminates, theory, elastic properties, orientation(direction), composite structures, three dimensional, solutions(general), integration, plates, anisotropy, isotropism, convergence, thinness, behavior, nonlinear analysis, static tests, formulas(mathematics), lagrangian functions, fibers DTIC Identifier(s): Laminates, plates, structural response, composite structures, finite element analysis, nonlinear analysis, stress strain relations, theses, displacement, buckling, interpolation. Author(s) subject terms: Finite element, nonlinear analysis, plate bending thick plates, laminated composites, buckling, constant arc length three dimensional element Includes bibliographical references (p. 87-88). Also available in print.

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Smith, Michael. "Elasto-plastic large deformation analysis of beams and shells using finite elements." Thesis, Kingston University, 1987. http://eprints.kingston.ac.uk/20513/.

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The complete analysis of problems of solid mechanics must include the nonlinear effects of large deformations, inelastic material behaviour and changing boundary conditions. The finite element analysis of such problems using continuum finite elements is well established. However, the analysis of such problems using structural finite elements such as beams, plates and shells is still subject to restrictions which do not apply to continuum elements. The removal of these restrictions is important because (i) structural finite elements are widely used in current engineering practice (ii) the reduced number of variables associated with these elements leads to greater computational efficiency. The work carried out and reported in this thesis addresses the following areas of finite element analysis; the geometrically nonlinear analysis of two- and three-dimensional beams subject to arbitrarily large displacements and rotations; the elasto-plastic analysis of two- and three-dimensional beams using both multi-fibre and stress resultant approaches; the nonlinear analysis of two-dimensional reinforced concrete beams; the elasto-plastic analysis of shells using both the multi-layer and stress resultant approaches. A wide range of two- and three-dimensional problems have been analysed and the results reported. These problems cover a large number of two-dimensional beam, frame and arch problems including geometric and material nonlinearity. Results are compared with simple beam theory, other analytical solutions such as elliptic integrals, other finite element results and experimentation. Other problems analysed are three-dimensional beams with geometric and material nonlinearity, imperfect steel plates subject to large deformation elasto-plastic behaviour and two sample shell problems of practical application.

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Rowe, Johnathan. "FINITE ELEMENT MODELING OF AN INFLATABLE WING." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/475.

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Inflatable wings provide an innovative solution to unmanned aerial vehicles requiring small packed volumes, such as those used for military reconnaissance or extra-planetary exploration. There is desire to implement warping actuation forces to change the shape of the wing during flight to allow for greater control of the aircraft. In order to quickly and effectively analyze the effects of wing warping strategies on an inflatable wing, a finite element model is desired. Development of a finite element model which includes woven fabric material properties, internal pressure loading, and external wing loading is presented. Testing was performed to determine material properties of the woven fabric, and to determine wing response to static loadings. The modeling process was validated through comparison of simplified inflatable cylinder models to experimental test data. Wing model response was compared to experimental response, and modeling changes including varying material property models and mesh density studies are presented, along with qualitative wing warping simulations. Finally, experimental and finite element modal analyses were conducted, and comparisons of natural frequencies and mode shapes are presented.

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Hutchinson, Rodolfo. "TWO DIMENSIONAL LINEAR FINITE ELEMENT ANALYSIS OF POST-TENSIONED BEAMS." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3936.

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The objective of this research project was to create a Finite Element Routine for the Linear Analysis of Post-Tensioned beams using the program CALFEM® [20] developed at the division of Structural Mechanics in Lund University, Sweden. The program CALFEM and our own made files were written in MATLAB, an easy to learn and user-friendly computer language. The approach used in this thesis for analyzing the composite beam consists in embedding the steel tendons at the exact location where they intersect the concrete parent elements, without moving the concrete parent element nodes. The steel tendons are represented as one dimensional bar elements inserted into the concrete parent elements, which at the same time are represented as 8 node Iso-parametric plane elements. The theory presented in Ref. [4] served as basis for the modeling of the post-tensioned beams; however it only explained the procedure for modeling simple reinforced concrete beams, due to this we needed to make the appropriate adjustments so we could model post-tensioned beams. Assembly of the tendon stiffness into the concrete elements will depend on the bond interface between the steel and concrete, this bonding effect will be modeled using link elements; the stiffness of this link element used in the concrete-tendon interface will be the change in cohesion (between the grout or duct and the steel tendon) at the interface due to the relative slip between the concrete and the steel elements nodes. Loads (Distributed, Concentrated or Post-Tensioning) are applied directly into the concrete parent elements, and then from their resultant displacement the displacements and forces of all the steel tendon elements are obtained, this is done consecutively for all the post-tensioned tendons at every load increment. Four examples from different references and software programs are solved and compared with our results: (1) A simply reinforced cantilever plate. (2) A reinforced concrete beam, under the effect of a vertical concentrated load at mid-span. For this problem the force distribution along the steel reinforcement is obtained for two conditions, perfectly bonded and perfectly un-bonded, our results are compared with the ones obtained with the program SEGNID. (3) Consists of a continuous un-bonded post-tensioned beam with two spans, without stress losses on the tendon. The reactions at the supports and the concrete stress distribution at the location of the mid-support are obtained after the post-tensioning force is applied at both ends. (4) Consist on a un-bonded post-tensioned beam with stress losses on the tendons due to friction, wobbling and anchorage loss, under gradual loading and consecutive post-tensioning of two tendons, the results are compared with the ones reported using the program BEFE [5] developed at the University of Technology Graz, Austria. The results obtained using our program are very similar to the ones obtained with the other programs, including the more powerful curved embedded approach used by BEFE [5].
M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering

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McIvor, James David Colin. "The analysis of dynamically loaded flexible journal bearings using higher-order finite elements." Thesis, King's College London (University of London), 1988. https://kclpure.kcl.ac.uk/portal/en/theses/the-analysis-of-dynamically-loaded-flexible-journal-bearings-using-higherorder-finite-elements(8cb1e4bc-41a7-4a66-bf72-5b5e93668509).html.

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An efficient and robust predictive technique has been developed for the analysis of dynamically loaded, flexible journal bearings using the finite element method. The work is in two parts. In the first part a fast predictive technique is developed for the analysis of dynamically loaded, rigid journal bearings. The finite element formulation of Reynolds equation is presented using both 3-node triangular and 8-node isoparamteric elements to model the lubricant film. The latter are shown to approximate the problem more closely using fewer nodal points and hence requiring fewer equations. The Gauss-Seidel over-relaxation method is used to solve the resulting system equations and the sparseness of these equations is exploited. Comprehensive results are presented for the Ruston and Hornsby 6VEB Mk ifi marine diesel engine connecting rod bearing. Two different time stepping methods are considered and the effects of incorporating various oil feed features in the analysis are also presented. The second part of the work deals with the flexible bearing problem. The method of carrying out the structural modelling and the way in which the structural compliance relationships are obtained is described. A fast matrix inversion technique used to obtain these relationships is also described. Based on the rigid bearing work 8-node isoparametric elements are used to model the lubricant film. Two methods are presented for coupling the structural and lubrication analysis. The first method, the under-relaxation method, although proving straightforward to implement is shown to be unsatisfactory for this particular problem due to to convegnence problems. The second method is the Newton-Raphson method which is shown to be highly convergent. The Newton-Raphson method is subsequently highly modified to produce a fast solution method. This is shown to be several orders of magnitude faster than any previously developed method making this technique viable as a general design tool rather than just providing benchmarks against which to compare simpler analysis techniques. Again results are presented for the Ruston bearing showing the effect upon the predicted performance of incorporating elasticity into the analysis.

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Das, Manabendra. "Aeroelastic Analysis of Rotor Blades Using Three Dimensional Flexible Multibody Dynamic Analysis." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195601.

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This study presents an approach based on the floating frame of reference method to model complex three-dimensional bodies in a multibody system. Unlike most of the formulations based on the floating frame of reference method, which assume small or moderate deformations, the present formulation allows large elastic deformations within each frame by using the co-rotational form of the updated Lagrangian description of motion. The implicit integration scheme is based on the Generalized-alpha method, and kinematic joints are invoked in the formulation through the coordinate partitioning method. The resulting numerical scheme permits the usage of relatively large time steps even though the flexible bodies may experience large elastic deformations. A triangular element, based on the first order shear deformable theory, has been developed specifically for folded plate and shell structures. The plate element does not suffer from either shear or aspect-ratio locking under transverse and membrane bending, respectively. A stiffened plate element has been developed that combines a shear deformable plate with a Timoshenko beam. A solid element, that utilized the isoparametric formulation along with incompatible modes, and one-dimensional elements are also included in the element library. The tools developed in the present work are then utilized for detailed rotorcraft applications. As opposed to the conventional approach of using beam elements to represent the rotor blade, the current approach focuses on detailed modeling of the blade using plate and solid elements. A quasi-steady model based on lifting line theory is utilized to compute the aerodynamic loads on the rotor blade in order to demonstrate the capabilities of the proposed tool to model rotorcraft aeroelasticity.

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Koko, Tamunoiyala Stanley. "Super finite elements for nonlinear static and dynamic analysis of stiffened plate structures." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30723.

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The analysis of stiffened plate structures subject to complex loads such as air-blast pressure waves from external or internal explosions, water waves, collisions or simply large static loads is still considered a difficult task. The associated response is highly nonlinear and although it can be solved with currently available commercial finite element programs, the modelling requires many elements with a huge amount of input data and very expensive computer runs. Hence this type of analysis is impractical at the preliminary design stage. The present work is aimed at improving this situation by introducing a new philosophy. That is, a new formulation is developed which is capable of representing the overall response of the complete structure with reasonable accuracy but with a sacrifice in local detailed accuracy. The resulting modelling is relatively simple thereby requiring much reduced data input and run times. It now becomes feasible to carry out design oriented response analyses. Based on the above philosophy, new plate and stiffener beam finite elements are developed for the nonlinear static and dynamic analysis of stiffened plate structures. The elements are specially designed to contain all the basic modes of deformation response which occur in stiffened plates and are called super finite elements since only one plate element per bay or one beam element per span is needed to achieve engineering design level accuracy at minimum cost. Rectangular plate elements are used so that orthogonally stiffened plates can be modelled. The von Karman large deflection theory is used to model the nonlinear geometric behaviour. Material nonlinearities are modelled by von Mises yield criterion and associated flow rule using a bi-linear stress-strain law. The finite element equations are derived using the virtual work principle and the matrix quantities are evaluated by Gauss quadrature. Temporal integration is carried out using the Newmark-β method with Newton-Raphson iteration for the nonlinear equations at each time step. A computer code has been written to implement the theory and this has been applied to the static, vibration and transient analysis of unstiffened plates, beams and plates stiffened in one or two orthogonal directions. Good approximations have been obtained for both linear and nonlinear problems with only one element representations for each plate bay or beam span with significant savings in computing time and costs. The displacement and stress responses obtained from the present analysis compare well with experimental, analytical or other numerical results.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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Pigozzo, Mônica Nogueira. "Avaliação das tensões transmitidas às estruturas de suporte, por meio da associação dos métodos fotoelástico e de elementos finitos, decorrentes das forças aplicadas sobre overdentures retidas em implantes com sistema de encaixe barr." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/23/23150/tde-18112010-103845/.

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O objetivo desta pesquisa foi avaliar in vitro as tensões transmitidas às estruturas de suporte, por meio da associação dos métodos fotoelásticos e elementos finitos, decorrentes da aplicação de forças sobre overdentures retidas em implantes com sistema de encaixe barraclipe, particularmente quando duas posições dos implantes são simuladas. Assim, dois modelos fotoelásticos de mandíbulas foram confeccionados, com dois implantes cada um, posicionados na região interforaminal a 22 mm de distância: modelo 1, denominado AFIP, modelo fotoelástico com implantes paralelos e orientados verticalmente; e modelo 2, denominado AFII, modelo fotoelástico com implantes angulados 10º em relação à linha média da mandíbula. Sobre os implantes, em cada modelo, foi posicionada uma prótese tipo overdenture, com sistema de retenção barra-clipe. Para simulação da mucosa, foi interposta entre a base da prótese e o rebordo residual uma camada de 2 mm de silicone. Este mesmo modelo foi representado para uma análise tridimensional (3D) de elementos finitos. As estruturas foram consideradas homogêneas, isotrópicas e lineares, além de serem atribuídas as correspondentes propriedades mecânicas para cada uma delas. Foram simuladas quatro mandíbulas de elementos finitos, sendo modelo 1, denominado EFRIP, com implantes paralelos; modelo 2, denominado EFRII, com implantes angulados em 10º, ambos modelos (1 e 2) simulando o modelo mandibular de resina fotoelástica; modelo 3, denominado EFOIP, com implantes paralelos; e modelo 4, denominado EFOII, com implantes angulados em 10º, ambos os modelos (3 e 4), simulando os ossos cortical e trabecular. Foram aplicadas cargas de 0,5; 1,0; 1,5; 2,0 e 3 bar no método fotoelástico e 0,1 MPa no método de elementos finitos e em seguida as imagens foram fotografadas e analisadas. Os resultados mostraram que: não houve semelhança entre as áreas de tensão dos modelos de resina fotoelástica, quando avaliada a angulação dos implantes (modelo 1 AFIP - e modelo 2 AFII). Houve semelhança entre as áreas de tensão nos modelos de elementos finitos com mandíbula em resina (modelo 1 EFRIP - e modelo 2 EFRII), tendo ocorrido o mesmo entre os modelos de elementos finitos com simulação de osso (modelo 3 - EFOIP - e modelo 4 EFOII) quando avaliada a inclinação dos implantes. Quando comparados os diferentes modelos com a mesma angulação de implante, observou-se que houve semelhança na distribuição das áreas de tensão entre os modelos 1 (AFIP e EFRIP), com uma alta concentração de tensão nos ápices dos implantes. Porém, não houve relação entre os modelos de implantes inclinados, modelos 2 (AFII e EFRII). Da mesma forma, não houve relação entre os modelos de análise fotoelástica e elementos finitos com simulação de mandíbula em resina, independentemente da angulação dos implantes, comparado os modelos de elementos finitos com simulação de osso. Frente às limitações do presente trabalho, concluiu-se que a associação dos métodos de análise fotoelástica e de elementos finitos é de grande valia para a obtenção de informação em relação à biomecânica referente a esse tipo de prótese e sistema de retenção. Além disso, houve semelhança nas áreas de concentração de tensão, quando comparado os modelos de análise fotoelástica e de elementos finitos, quando as propriedades mecânicas inseridas no modelo de elementos finitos foram compatíveis com o modelo fotoelástico, pois, quando o modelo de elementos finitos simulou uma mandíbula com diferenciação entre osso cortical e medular, as áreas de concentração de tensão sofreram alterações.
The objective of this study was to appraise in vitro the load transmission in bar-clip retention system for overdenture when two implant positions are simulated, using for this purpose the association of photoelastic analysis and finite elements techniques. Therefore, two photoelastic mandible were manufactured with two implants each one, positioned in interforaminal region within 22 mm of distance: (i) model 1, named AFIP, photoelastic model with parallel and vertically oriented implants; and (ii) model 2, named AFII, photoelastic model with 10º angled implants in relation to mandible midline. A bar-clip retention system and an overdenture were fixed over both implants. To simulate oral mucosa were added a 2 mm silicon layer between overdenture prosthesis and photoelastic mandible. This same model was submitted to finite elements analysis in 3D, being attributed the correspondent mechanic properties to each structure analyzed and also being considered homogenous, isotropic and linear characteristics. Four finite elements mandible were simulated, (i) one with parallel implants and (ii) other with 10º angled implants, simulating photoelastic resin in mandible (models 1 and 2, named EFRIP and EFRII respectively); and a another couple of mandibles also with (iii) parallel and (iv) 10º angled implants, simulating cortical and cancellous bones in mandible (models 3 and 4, named EFOIP and EFOII respectively). 0.5; 1.0; 1.5; 2.0 and 3.0 bars loads were applied and correspondent images were analyzed. Results evidenced that there is no similarity in loaded areas between photoelastic resin models, when the implant angle is appraised in models 1 and 2 (AFIP and AFII). Notwithstanding, there are similarity between loaded areas in finite elements model with resin mandible, models 1 and 2 (EFRIP and EFRII), and the same have occurred with finite elements models with bone simulation, models 3 and 4 (EFOIP and EFOII), when appraised implant inclination. When different models are compared with the same implant angulations, was noted that there was similarity in the distribution of loaded areas between models 1 (AFIP and EFRIP), with high concentration of tension forces at the implant apex. Nevertheless, there was no relation between inclined models 2 (AFII and EFRII). At the same direction, there was no relation between photoelastic analysis and finite elements with resin model, with no influence of implant angulations, with finite element models with bone simulation. Considering the limitations of this study, it was concluded that association of photoelastic analysis and finite elements has a high potential value for obtaining information concerning the biomechanics of this kind of prosthesis and retention system; furthermore, there was similarity in areas where loads were applied, when compared photoelastic and finite elements models, provided that finite elements mechanic properties are compatible with photoelastic model, since concentration areas of tension forces suffer changes when finite elements model simulates a mandible with cortical and cancellous bones differentiation.

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Khokhar, Zahid R. "Finite-element analysis of delamination in CFRP laminates : effect of material randomness." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6125.

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Laminated carbon fibre-reinforced polymer (CFRP) composites are already well established in structural applications where high specific strength and stiffness are required. Damage in these laminates is usually localised and may involve numerous mechanisms, such as matrix cracking, laminate delamination, fibre debonding or fibre breakage. Microstructures in CFRPs are non-uniform and irregular, resulting in an element of randomness in the localised damage. This may in turn affect the global properties and failure parameters of components made of CFRPs. This raises the question of whether the inherent stochasticity of localised damage is of significance for application of such materials. This PhD project is aimed at developing numerical models to analyze the effect of material randomness on delamination damage in CFRP materials by the implementation of the cohesive-zone model (CZM) within the framework of the finite-element (FE) method. Both the unidirectional and cross-ply laminates subjected to quasi-static loading conditions were studied. The initiation and propagation in delamination of unidirectional CFRP laminates were analyzed. The CZM was used to simulate the progress of that failure mechanism in a pre-cracked double-cantilever beam (DCB) specimen loaded under mode-I employing initially, a two-dimensional FE model. Model validation was then carried out comparing the numerical results with experimental data. The inherent microstructural stochasticity of CFRP laminates was accounted for in the simulations, and various statistical realizations for a half-scatter of 50% of fracture energy were performed, based on the approximation of that parameter with the Weibull s two-parameter probability density function. More detailed analyses were undertaken employing three-dimensional DCB models, and a number of statistical realizations based on variation of fracture energy were presented. In contrast to the results of two-dimensional analyses, simulations with 3D models demonstrated a lower load-bearing capacity for most of the random models as compared to the deterministic model with uniform material properties. The damaged area and the crack lengths in laminates were analyzed, and the results showed higher values of those parameters for random realizations compared to the uniform case for the same levels of applied displacement. The effect of material randomness on delamination in CFRP cross-ply laminates was also investigated. Initially, two-dimensional finite-element analyses were carried out to study the effect of microstructural randomness in a cross-ply laminate under bending with the direct introduction of matrix cracks with varying spacings and delamination zones. A considerable variation in the stiffness for cases with different crack spacings suggested that the assumption of averaged distributions of defects can lead to unreliable predictions of structural response. Three-dimensional uniform, deterministic cross-ply laminate models subjected to a tensile load were analyzed to study the delamination initiation and propagation from the tips of a pre-existing matrix crack. The material s stochasticity was then introduced, and a number of random statistical realizations were analyzed. It was observed that by neglecting the inherent material randomness of CFRP laminates, the initiation conditions for delamination as well as the character of its propagation cannot be properly detected and studied. For instance, the delamination crack length value for all the simulated random statistical realizations predicted its higher magnitudes compared to the uniform (deterministic) case for the same value of applied strain. Furthermore, the location of delamination initiation was shown to be different for different random statistical realizations. Another aspect, emphasizing the importance of microstructural randomness, was the scatter in the magnitudes of global strain at the instance of initiation and subsequent propagation of delamination. In summary, the material randomness in CFRPs can induce randomness in localised damage and it can affect the global properties of laminates and critical failure parameters. These effects can be investigated computationally through the use of stochastic cohesive-zone elements.

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Ho, Man Him. "Earthquake-induced random vibration analysis of cable-stayed bridge with finite strip elements." Thesis, University of Macau, 2001. http://umaclib3.umac.mo/record=b1445038.

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Wong, Weng Heng. "Wind-induced random vibration analysis of cable-stayed bridge with finite strip elements." Thesis, University of Macau, 2000. http://umaclib3.umac.mo/record=b1636333.

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Mohammed, Abuu Khalifa. "Nonlinear Shell Finite Elements for Ultimate Strength and Collapse Analysis of Ship Structures." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-79.

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The present thesis deals with ultimate strength and collapse analysis of ship structures. Within this are, the attention is directed towards simple and efficient nonlinear finite element models for stiffened plate panels in ship structures. Several types of Morley elements are investigated and two are selected for further development. These triangular elements assume constant stress distribution over the element area.

The first element considered is a nonlinear facet shell element which is valid within moderate rotations. Its elastic formulation has been proposed earlier. In this work, the element matrices are extended to account for material plasticity. The second element, is a displacement-based curved element which undergoes arbitrary large displacements and rotations. The discrete equilibrium equations for this element are re-derived so as to make them more efficient with standard Newton-Raphson solution procedures.

Material plasticity formulation using through-the thickness integration as well as resultants plasticity is presented. The evolution laws are derived from the natural laws of thermodynamics, and a return mapping algorithm with a backward Euler difference scheme is used for a solution of the evolution equations. The plasticity computations involve a solution of a single scalar yield surface for the plasticity multiplier. By performing the matrix algebra analytically, simple and explicit expressions are derived. These equations reduce the computational costs remarkably.

Numerical examples, mostly selected from well-know benchmark problems, are presented to demonstrate the performance of the proposed formulations. Very good agreement is obtained when compared with published results. In addition, typical problems for ultimate strength and collapse analysis of ship hull-girder are analyzed. These include plate girders, stiffened plate panels, as well as a cruciform element. The results show good agreement not only with those obtained from commercial finite element programs, but also from the experimental observations. For stiffened plate panels, comparison is made with DNV design rules, which is found to give non-conservative estimates for some load conditions.

Finally, a study on multi-span stiffened panels is performed so as to compare the estimates provided by the conventional single span model. It is observed that the conventional model provides conservative estimates, and the effect of transverse frames is especially significant on the finite element model of stiffened panels.

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