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1
Ledger, P. D. "An HP-adaptive finite element procedure for electromagentic scattering problems." Thesis, Swansea University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637864.
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This thesis presents an adaptive finite element procedure for electromagnetic scattering problems in two dimensions. The work addresses the issues of higher order basis functions and demonstrates their advantages over lower order approximations. A new a-posteriori error estimator is derived which is capable of producing bounds on non-linear outputs of the scattering problem. Subsequently, this is used to automatically adapt both the polynomial order and the mesh spacing. The effectiveness of the procedures are demonstrated through a series of examples.
2
Zheng, Hui. "Application of the hybrid finite element procedure to crack band propagation." Ohio : Ohio University, 1987. http://www.ohiolink.edu/etd/view.cgi?ohiou1183125160.
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Nguyen, Vinh Dinh. "A finite element mesh optimization procedure using a thermal expansion analogy." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/101248.
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Finite element optimum meshes are synthesized by the use of thermal expansion principles in conjunction with an analogous temperature field computed from the element strain energy contents. Elements having high strain energy contents are shrunk and those with low strain energy contents are expanded until all elements contain the same amount of strain energy. Deviatoric strain energy is also used in place of the strain energy as the objective function for the optimization method. Both objective functions yield significant improvements of the meshes after only a few iterations. In one test case, the errors in the maximum stresses are reduced by more than 1/3 after 1 iteration. In another test case, the error in the stress concentration factor is reduced by more than 3/4 after 7 iterations.M.S.
4
Balasubramaniam, Krishna. "A finite element procedure for assessing continuous flaws in clad pressure vessels." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/11800.
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Pantuso, Daniel. "A finite element procedure for the analysis of thermo-mechanical solids in contact." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10441.
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Zhang, Wu. "Adaptive stochastic finite element procedure of electronic packaging problems using disturbed state concept." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282373.
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Complex engineering problems need appropriate constitutive laws such as Disturbed State Concept (DSC), as well as robust accurate computational analysis methods such as adaptive and stochastic finite element methods (FEM). DSC provides a unified basis for constitutive modeling including elastic, plastic and creep deformations, microcracking, damage and softening, stiffening, and cyclic fatigue under thermomechanical loading. It includes intrinsical regularization, localization, characteristic dimension and avoidance of spurious mesh dependence. It also leads to new procedures for adaptive FEM and stochastic FEM. Adaptive FEM is a method to adapt or guide itself to better subsequent computation by use of previous computational information so as to achieve prescribed accuracy. It's a powerful procedure for analyzing deformation of special problems such as interfaces and joints and shear bands, and complex materials with both hardening and softening. An adaptive finite element procedure with combined Disturbance-Hybrid stress error estimator/remeshing indicator is proposed and tested by comparing with some published results, and the corresponding user-interactive unified DSC finite element program with more than 10 options is developed and applied to thermal analysis of electronic packaging problems. Unlike deterministic analysis methods, stochastic FEM approach further considers the random variations of involved parameters to further make the deterministic constitutive and numerical modeling more realistic in a statistical manner. Traditional stochastic FEM is reviewed and a new efficient DSC stochastic FEM is formulated for reliability analysis of electronic packaging problems. The computer visualization and animation are applied to display the computed results for the purpose of easier use and interpretation of the results, which will be one of major trends for engineering application of computational methods. In this dissertation, combined study is carried out from a comprehensive (computational and constitutive) viewpoint, and the practical and academic values of the adaptive and stochastic DSC finite element procedures for electronic packaging problems will be demonstrated.
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Burton, Christopher Geoffrey. "A procedure for predicting the stresses in gas turbine blades using finite element analysis." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/46980.
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Butler, Martin A. "Fracture Critical Analysis Procedure for Pony Truss Bridges." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin155351691314481.
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Larkin, Cory W. "A Modified Design Procedure for the Fused Steel Coupling Beam System." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1394725015.
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Loehr, John Erik. "Development of a hybrid limit equilibrium-finite element procedure for three-dimensional slope stability analysis /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Alhameedi, Ali. "Hybrid testing procedure development : An experimental study a hybrid simulation of a steel truss element." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-90786.
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Hybrid simulation is a numerical and experimental structural testing technique in which the critical structural members are tested experimentally, while the rest of the structure is modeled numerically. During hybrid testing, the numerical model is updated continuously based on the output of the experimental test. In this study, a quasi-static hybrid simulation was conducted on a steel truss structure. A single truss member was considered as the physical substructure, while the remaining members were modeled using Abaqus finite element software. The communication between the physical and numerical models was established using OpenFresco as a middleware. Using this setup, the structure was loaded until the physical substructure failed due to buckling. Finally, the results of the hybrid simulation were verified numerically and experimentally.
12
Wu, Shu-Wei. "A fast, robust and accurate procedure for radiation and scattering analyses of submerged elastic axisymmetric bodies." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46618.
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Bohle, Eva. "Proving genocidal intent and the policy element :genocide in Darfur?" Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_2738_1297749409.
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The International Commission of Inquiry on Darfur (Commission) began its work in October 2004 and provided its final report only three months later on 25 January 2005.2 There, it concluded, inter alia, &ldquo
that the Government of Sudan has not pursued a policy of genocide&rdquo
and that at least the central Government authorities did not act with genocidal intent.3 However, these findings would not exclude the possibility that the atrocities committed by individuals against victims were carried out with the specific intent to destroy and therefore could possibly fulfil all necessary requirements of the crime of genocide.
14
Grove, Alewyn Petrus. "Development of a finite element based nominal stress extraction procedure for fatigue analysis of welded structures." Diss., University of Pretoria, 2006. http://upetd.up.ac.za/thesis/available/etd-12182007-125836/.
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Shirzadi, Mohammad Mehdi. "Development of a patient-specific finite element model of the transcatheter aortic valve implantation (TAVI) procedure." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22893.
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Transcatheter Aortic Valve Implantation (TAVI) is a procedure developed for replacing the defective aortic valve of a patient as an alternative to open heart Surgical Aortic Valve Replacement (SAVR). In the TAVI procedure a prosthetic valve, which is assembled on to a stent, is crimped and delivered to the patient's aortic root site through several available percutaneous means. The percutaneous nature of TAVI, which is its core advantage in comparison to other SAVR procedures, can however also be its main disadvantage. This is due to lack of direct access to the calcified leaflets, and hence reliance on the host tissue for the proper positioning and anchorage of the deployed prosthetic valve. Therefore, it is desired to have a preoperative quantitative understanding of patient-specific biomechanical interaction of the stent and the native valve to be able to maximise the chance of success of the procedure. The aim of this study was to develop a patient-specific Finite Element (FE) model of the Transcatheter Aortic Valve Implantation (TAVI) procedure for two patients, using a model of the 23 mm percutaneous prosthetic aortic valve developed by Strait Access Technologies (SAT), for the purpose of its post-operative performance. In this regard, the image processing software ScanIP was used to extract the 3D models of the patient-specific aortic roots and leaflets from the provided Multi-Slice Computer Tomography (MSCT) images of the patients. An anisotropic hyperelastic material model was implemented for the roots and leaflets, using two and one families of collagen fibres for their tissues respectively. The stent is made of a cobalt-chromium alloy and its mechanical response was modelled as an isotropic elastoplastic material, with a linear elastic initial response, followed by plastic behaviour with isotropic hardening. The prosthetic leaflets are made of polymer and were modelled as an isotropic hyperelastic material, using the provided experimental test data. The results for the first patient showed that the stent maintained its structural integrity after deployment, and successfully pushed the native leaflets back to keep the aortic root clear of all impediments. No obstruction of the coronary ostia was observed, and prosthetic leaflets were seen to function normally. The stent radial recoil was calculated to be between 2 to 4.28 % after deployments. Its foreshortening was calculated to be approximately 20%. The stent was observed to move back and forth by approximately 3 mm in the last simulation step in which cardiac cycle pressure were applied to the aortic root and prosthetic leaflets. Also, two openings were observed between the stent and aortic root wall during this simulation step, which indicates the possibility of paravalvular leakage. From the second patient simulation, it was observed that the 23 mm stent was not a good choice for this patient, and will cause severe damage or tissue tearing. The maximum principal stress in the aortic root and valve tissues were observed to follow approximately the defined collagen fibre directions.
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Kapoor, Hitesh. "Isogeometric Finite Element Code Development for Analysis of Composite Structures." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/50567.
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This research endeavor develops Isogeometric approach for analysis of composite structures and take advantage of higher order continuity, smoothness and variation diminishing property of Nurbs basis for stress analysis of composite and sandwich beams and plates. This research also computes stress concentration factor in a composite plate with a hole.Isogeometric nonlinear/linear finite element code is developed for static and dynamic analysis of laminated composite plates. Nurbs linear, quadratic, higher-order and k-refined elements are constructed using various refinement procedures and validated with numerical testing. Nurbs post-processor for in-plane and interlaminar stress calculation in laminated composite and sandwich plates is developed. Nurbs post-processor is found to be superior than regular finite element and in good agreement with the literature. Nurbs Isgoemetric analysis is used for stress analysis of laminated composite plate with open-hole. Stress concentration factor is computed along the hole edge and good agreement is obtained with the literature. Nurbs Isogeometric finite element code for free-vibration and linear dynamics analysis of laminated composite plates also obtain good agreement with the literature.
Main highlights of the research are newly developed 9 control point linear Nurbs element, k-refined and higher-order Nurbs elements in isogeometric framework. Nurbs elements remove shear-locking and hourglass problems in thin plates in context of first-order shear deformation theory without the additional step and compute better stresses than Lagrange finite element and higher order shear deformation theory for comparatively thick plates i.e. a/h = 4. Also, Nurbs Isogeometric analysis perform well for vibration and dynamic problems and for straight and curved edge problems.
Ph. D.
17
Guney, Murat Efe. "A Numerical Procedure For The Nonlinear Analysis Of Reinforced Concrete Frames With Infill Walls." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606318/index.pdf.
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Materially non-linear analysis of reinforced concrete frame structures with infill walls requires appropriate mathematical models to be adopted for the beams and the columns as well as the infill walls. This study presents a mathematical model for frame elements based on a 3D Hermitian beam/column finite element and an equivalent strut model for the infill walls. The spread-of-plasticity approach is employed to model the material nonlinearity of the frame elements. The cross-section of the frame element is divided into triangular sub regions to evaluate the stiffness properties and the response of the element cross-section. By the help of the triangles spread over the actual area of the section, the bi-axial bending and the axial deformations are coupled in the inelastic range. A frame super-element is also formed by combining a number of frame finite elements.
Two identical compression-only diagonal struts are used for modeling the infill. The equivalent geometric and material properties of the struts are determined from the geometry of the infill and the strength of the masonry units
A computer code is developed using the object-oriented design paradigm and the models are implemented into this code. Efficiency and the effectiveness of the models are investigated for various cases by comparing the numerical response predictions produced by the program with those obtained from experimental studies.
18
Fietsam, James. "Development of a procedure for the certification of canopies for underground mining equipment using finite element analysis software." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2496.
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Underground mining equipment is required by the Mine Safety and Health Administration to have certified overhead protective structure, referred to here as a canopy. By reviewing previous works in the area of protective canopies and utilizing their findings to
19
Cardon, Ludwig Kamiel Stefan. "A generic procedure for mould material thermal behaviour modelling using finite element simulation of hybrid plastic injection moulds." Thesis, Birmingham City University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435526.
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Schippers, Jared D. "A Design Procedure for Bolted Top-and-Seat Angle Connections for Use in Seismic Applications." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1336137999.
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Berlin, Michael West. "Innovative procedure to install a trunnion-hub assembly in a bascule bridge girder." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000525.
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Tarar, Wasim Akram. "A New Finite Element Procedure for Fatigue Life Prediction and High Strain Rate Assessment of Cold Worked Advanced High Strength Steel." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1204575243.
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Aminjikarai, Vedagiri Srinivasa Babu. "An Automated Dynamic Fracture Procedure and a Continuum Damage Mechanics Based Model for Finite Element Simulations of Delamination Failure in Laminated Composites." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1242963775.
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Yun, SeongKyu. "Development of the numerical procedure to describe multi-dimensional behavior of the alternating Pleistocene foundations." Kyoto University, 2020. http://hdl.handle.net/2433/245842.
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Cai, Qingbo. "Finite element modelling of cracking in concrete gravity dams." Thesis, Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-01302008-160623.
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McElroy, Mark Allen. "A Procedure for Generating Finite Element Models (FEM) of Abdominal Aortic Aneurysms with Fluid Boundary Conditions Derived from Magnetic Resonance Imaging (MRI) Velocimetry." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1284670607.
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Grande, García Eduardo [Verfasser], Ernst [Akademischer Betreuer] Rank, and Rainer H. H. [Akademischer Betreuer] Burgkart. "Double Experimental Procedure for Model-Specific Finite Element Analysis of the Human Femur and Trabecular Bone / Eduardo Grande García. Gutachter: Ernst Rank ; Rainer H. H. Burgkart. Betreuer: Ernst Rank." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1034420739/34.
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Sklenář, Filip. "Analýza provozních rizik nově zaváděných typů letadel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231641.
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This thesis examines the process of introducing a new aircraft into the service, in particular by the steps from initial vision of a new aircraft until after the aircraft. The content of the thesis consists of seven parts. In the first four sections, I describe the organizations involved in aviation and reliability, physical principles of aircraft systems, accident statistics, regulatory requirements. The fifth section focuses on reliability and describes the procedures for the analysis of reliability. The sixth part is focused on the procedure for introducing new aircraft into service and also includes the methodology for eliminating the element of lack of confidence, which was one of the main objectives of this work. The seventh part is a demonstration of the procedure for the introduction of aircraft into operation.
29
Paw, G. F. "Parallel processing procedures for finite element analysis." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638432.
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The objective of the research is to improve the solution capability of a finite element system by the use of parallel processing techniques. Initial research began with the transputer system at a time when the transputer was considered the ultimate parallel machine. The transputer based parallel program LINSUB was developed to solve linear static stress analysis problems using a modified Cholesky algorithm for substruturing. Further developments in this field were halted when it became clear that other parallel systems, namely, those concerned with workstation clusters, were moving rapidly ahead of the transputer in terms of performance and the transputer was rapidly becoming obsolete. Further work concentrated on parallel processing on workstation clusters in a local area network and the effectiveness of the Parallel Virtual Machine (PVM) used as the supportive parallel environment was investigated. This work was then extended onto a shared memory - MIMD system on the Silicon Graphics Power Challenge workstation. The program PARFEI (PARallel Finite Element Implementation) was developed for large linear static stress analyses and nonlinear analyses of elasto-plastic problems in particular, using a multifrontal approach based on domain decomposition techniques. An implementation based on a specially designed share memory (SM) synchronization concept was incorporated into the same program, so that PARFEI can run sequentially or in parallel using either PVM or SM. Performance tests were carried out on the workstation clusters using PVM and on the shared memory machine using PVM and SM. The results revealed that, in general, PVM performed better for the linear system and SM was the more efficient of the two when an incremental/iterative process was involved.
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Lush, Allen M. "Computational procedures for finite element analysis of hot-working." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/13617.
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Carey, Cheryl M. M. "A procedure for optimal evaluation of shell finite elements." Thesis, Brunel University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334409.
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Galiläer, Peter. "Trassierung von Straßenverkehrsanlagen mit der Finiten Elemente Methode." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-33414.
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Für die Trassierung von Straßenverkehrsanlagen hat sich neben anderen Methoden die Verwendung von Biegelinealen als vorteilhaft erwiesen und vor über 50 Jahren etabliert. Inzwischen hat der Einsatz moderner Entwurfssoftware in den Straßenbauverwaltungen und Planungsbüros das Biegelineal trotz seiner Vorteile aus der Praxis verdrängt. Keines der Entwurfsprogramme legt das strukturmechanische Prinzip des Biegelineals zugrunde, da die Verformungen des zu Trassierungszwecken ausgelegten Biegelineals nicht exakt berechnet werden können.
An diesem Punkt setzt die vorliegende Arbeit an, sie umgeht das Problem auf numerischem Wege unter Anwendung der Finiten Elemente Methode (FEM). So lassen sich über Strukturanalysen die Verformungen einer um seine Hauptträgheitsachsen punktuell ausgelenkten, prismatischen Balkenstruktur mit doppeltsymmetrischem Querschnitt berechnen. Mit der Analyseantwort ergeben sich insbesondere die dreidimensionalen Koordinaten einer Punktfolge, welche die Biegelinie quasiexakt repräsentiert. Die dreidimensionale Biegelinie setzt sich aus einer Achse und einer Gradiente zusammen und ist im Rahmen der Vorplanung geeignet, eine richtliniengerechte Straßenverkehrsanlage zu erzeugen.
Das Untersuchungsergebnis stellt eine neuartige Grundlage für ein dreidimensionales Trassierungsverfahren dar, bei dem ein mathematisch modelliertes Biegelineal im Digitalen Geländemodell (DGM) verformt wird.
33
Hulett, Cameron. "Design procedures for high temperature components using finite element methods." Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/14306.
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Bibliography: leaves 109-114.A procedure for design and redesign of high temperature components is developed. The thesis begins with a description of an engineering problem, namely the failure of a steel plant pre-reduction kiln, which incorporates a number of commonly occurring design problems. A redesign procedure, which follows a more prescriptive rather than a descriptive method, is established for the case study. An investigation of the material properties, loading conditions and component failure is undertaken. Each investigation begins with an overall view of the topic, which is then narrowed to suit the case study. The procedure developed during the investigations begins by using conventional theoretical techniques to determine the material properties and loadings involved. Simple and then more detailed finite element modelling establishes more accurate results for so.me complicated problems. In particular the thermal loading of the kiln is found to be considerably larger than the self weight loading. Failure analysis techniques together with a sophisticated non-destructive testing technique, Holographic Interferometry, are employed to investigate flaws and failure modes. The technique developed enables the qualification and quantification of material properties and flaws for in situ components. The dominant failure mode for the kiln is stress corrosion which can be prevented by avoiding corrosion and lowering the thermal stresses. However the existence of flaws enables fatigue failure to occur. The procedure continues with a life assessment due to fatigue, however in the kiln case study, the validity of this is uncertain due to insufficient test data. Recommendations for redesign are then given. The design procedure enables an ordered and effective means of solving in situ component failure and redesign problems.
34
Chow, Chak-On 1968. "On a posteriori finite element bound procedures for nonsymmetric Eigenvalue problems." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85266.
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Yang, Da-Ming. "Development of novel intelligent condition monitoring procedures for rolling element bearings." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU151909.
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The primary aim of this thesis is to develop a novel procedure for an intelligent automatic diagnostic condition monitoring system for rolling element bearings. The applicability of this procedure is demonstrated by its implementation in a particular electric motor drive system. The novel bearing condition diagnostic procedure developed involves three stages combining the merits of advanced signal processing techniques, feature extraction methods and artificial neural networks. This procedure is the effective combination of these techniques and methods in a holistic approach to the rolling element bearing problem which provides the novelty in this thesis. Maintenance costs account for an extremely large proportion of the operating costs of machinery. In addition, machine breakdowns and consequent downtime can severely affect the productivity of factories and the safety of products. It is therefore becoming increasingly important for industries to monitor their equipment systematically in order to reduce the number of breakdowns and to avoid unnecessary costs and delays caused by repair. The rolling element bearing is an extremely widespread component in industrial rotating machinery and a large number of problems arise from faulty bearings. Therefore, proper monitoring of bearing condition is highly cost-effective in reducing operating cost. The advanced signal processing techniques used here are bispectral-based and wavelet-based analyses. The bispectral-based procedures examined are the bis-pectrum, the bicoherence, the bispectrum diagonal slice, the bicoherence diagonal slice, the summed bispectrum and the summed bicoherence. The wavelet-based procedure uses the Morlet wavelet. These methods greatly enhance the ability of an automated diagnostic process by linking the increased capability for signal analysis to the predictive capability of artificial neural networks. The bearing monitoring scheme based on bispectral analysis is shown to provide greater insight into the structure of bearing vibration signals and to offer more diagnostic information than conventional power spectral analysis. The wavelet analysis provides a multi-resolution, time-frequency approach to extract information from the bearing vibration signatures. In order to effectively interpret the wavelet map, the time-frequency domain is used instead of the time-scale domain by plotting the associated time trace and power spectrum.
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Kyriakides, Nicolas. "Judicial discretion and contempt power : two elements of equity that would benefit the EAPO and future EU-wide provisional and protective measures." Thesis, University of Oxford, 2016. http://ora.ox.ac.uk/objects/uuid:91c8379a-252c-475c-995d-7d71dbb0d24f.
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A person filing a civil claim faces the risk of being unable to enforce a favourable judgment. This is because their opponent may dissipate his assets and consequently be unable to satisfy a judgment given against him. Several mechanisms seek to alleviate this risk by preserving the defendant's assets pending judgment. These are predominantly the civilian in rem order and the common law freezing order. Fundamental differences between the common and civil law traditions may be observed in the freezing order and its civilian counterpart. Primarily, these are to be found in the margin of discretion given to the judge and the sanctions against non-compliance. The latter issue is closely related to the entity against which an order is directed: in the common law it is directed against the person, while in the civil law, against the asset. The significantly diverse approaches in these areas show the different course each of the legal families has taken in the administration of justice. The problem of preserving assets pending judgment becomes more complicated when the assets are not located in the same country as the courts with jurisdiction on the merits. The recently introduced European Account Preservation Order (âEAPO') regulation is a pre-judgment instrument which enables a litigant to obtain an order preventing the transfer of funds held by the respondent in a bank account within the EU. It is the first of what may become several EU-wide provisional and protective measures. At first glance, the EAPO resembles the continental model rather than its common law counterpart, and, thus, brings into the open the differences between the two traditions in the area of provisional and protective measures. This work examines whether the features of the common law tradition - which in fact derive from the law of equity - ie judicial discretion in granting or refusing relief and contempt of court sanctions, could improve the EAPO as well as other EU-wide provisional and protective measures that may follow. It is argued that greater judicial discretion and a contempt sanction, provided that they are kept within certain limits, would improve the EAPO and similar measures in terms of efficiency and fairness.
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Barbosa, Ana Carolina Borba Lessa. "As medidas de urgência como elemento de avaliação da duração razoável de um processo temporalmente justo." Universidade Católica de Pernambuco, 2011. http://www.unicap.br/tede//tde_busca/arquivo.php?codArquivo=553.
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O presente trabalho tem por finalidade abordar as medidas de urgência como elemento de avaliação da duração razoável de um processo temporalmente justo. Tal como em
todos os trabalhos acadêmicos, que se procura encontrar uma resposta para uma dada pergunta, ou, a solução para um determinado problema, esta dissertação tem como
propósito procurar saber se as medidas de urgência, previstas no Código de Processo Civil, são suficientes para determinar a duração de um processo como temporalmente justo. Na elaboração do presente estudo foram abordadas as seguintes temáticas: as dimensões do tempo, sua relação com o universo jurídico e o contexto da urgência nessa
particularidade; os fundamentos do tempo e do Direito; as medidas de urgência no Direito (com enfoque para a prestação da tutela jurisdicional e a efetividade do processo
- garantia de uma duração razoável do processo e o reajustamento de garantias processuais, em termos de atenuação da duração e da simplificação processual); as
semelhanças e diferenças das cautelares e da antecipação dos efeitos da tutela sob a ótica de Piero Calamandrei e Ovídio Araújo Baptista da Silva; a constitucionalização da
tutela de urgência; o Direito na Pós-Modernidade e sua crise; e, a jurisdição de urgência e a necessidade de redimensioná-la. Chegando-se à conclusão de que as medidas de
urgência, previstas no Código de Processo Civil, são insuficientes para resolver os problemas da sociedade pós modernaThis study aims to address the urgent measures as an assessment of a reasonable duration of process temporally fair. As in all academic work, which seeks to find an answer to a given question or the solution to a given problem, this thesis aims to whether the emergency measures, the Code of Civil Procedure, are sufficient to determine the duration of a temporal process as fair. In preparing this study explored the following themes: the dimensions of time, his relationship with the universe and the legal context of urgency in this particularity, the grounds of time and law; emergency measures in the law (with a focus on the provision of and effectiveness of the judicial process ensuring a reasonable period of readjustment process and procedural guarantees in terms of attenuation of the duration and procedural simplification) the similarities and differences between the conservative and anticipating the effects of protection from the perspective of Piero Calamandrei and Ovid Baptista da Silva Araújo, a constitution for the protection of emergency; Law in Post-modernity and its crisis, and the jurisdiction of urgency and the need to resize it. He came to the conclusion that the emergency measures, the Code of Civil Procedure, are insufficient to solve the problems of postmodern society
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Neagoe, Catalin Andrei. "Structural performance of FRP-concrete hybrid beams with flexible shear connection." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/397749.
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La sostenibilidad de los edificios y de las infraestructuras públicas es un tema de importancia reciente puesto en discusión por la comunidad de ingeniería. La necesidad de diseñar estructuras con bajos requerimientos de mantenimiento y durabilidad a largo plazo puede ser resuelta mediante la introducción de nuevos materiales de construcción o la implementación de sistemas estructurales innovadores. En este sentido, los polímeros reforzados con fibras (FRP) representan una de las soluciones en el campo de la ingeniería civil que ofrecen resultados prometedores. Para optimizar el uso de secciones de FRP los investigadores han propuesto la creación de sistemas híbridos donde se combinan materiales compuestos con materiales convencionales, tales como el hormigón. Las soluciones híbridas mejoran la rigidez, la ductilidad y la resistencia a pandeo de los elementos aislados de material compuesto. Debido a la novedad y a la variedad de soluciones híbridas, la tecnología requiere de la realización de más ensayos experimentales para valorar su viabilidad. Además, en la actualidad hay una falta de códigos prescriptores y normas que ayuden al diseño de estructuras construidas con perfiles compuestos y, por consiguiente, los elementos mixtos requieren del desarrollo de modelos predictivos fiables. Por lo tanto, la presente investigación tiene como objetivo estudiar el comportamiento estructural de vigas híbridas hechas de perfiles pultrusionados de FRP unidos a losas de hormigón, mediante la realización de una investigación experimental, analítica y numérica. Puesto que los efectos de deslizamiento en la interfaz han sido mayoritariamente ignorados en el pasado, la tesis se centra también en la influencia de la flexibilidad de la conexión sobre el comportamiento de flexión. Con respecto a la campaña experimental, se han fabricado y ensayado a flexión ocho vigas de perfiles de FRP de fibra de vidrio (GFRP) y hormigón, con conectores mecánicos en el rasante. También se ha comparado su comportamiento con respecto a vigas de hormigón armado equivalentes y perfiles estructurales individuales de GFRP. Previamente a dichos ensayos, se propuso un procedimiento eficaz de caracterización no destructiva para la obtención de las propiedades elásticas de los materiales que componían los especímenes, mediante el uso de un análisis de la respuesta a la vibración libre. En general, los ensayos de flexión han demostrado la alta eficiencia estructural de la solución de viga híbrida y han subrayado la importancia de tener en cuenta la flexibilidad de conexión del rasante. También se ha desarrollado un procedimiento analítico para el diseño de vigas mixtas de FRP-hormigón bajo cargas a corto plazo. Se han propuesto ecuaciones de diseño para los estados límite de servicio y último en función de la interacción completa o parcial del rasante. Además, se ha analizado la viabilidad de utilizar fórmulas aproximadas para cuantificar los efectos del deslizamiento entre capas y su repercusión en la evaluación de los desplazamientos, la rigidez a flexión, la capacidad de flexión y las distribuciones de tensiones. Debido a la mejora de la precisión de las expresiones que representan la flexibilidad de la conexión del rasante, el procedimiento analítico propuesto ha sido capaz de capturar de manera adecuada el comportamiento estructural. Por último, en referencia a los análisis numéricos, se han desarrollado modelos de elementos finitos capaces de simular el comportamiento fundamental de vigas híbridas con conectores tipo perno. El modelo que representó las no linealidades en el material, en los contactos y en la geometría fue el que ofreció los mejores resultados en comparación con los datos experimentales y las estimaciones analíticas. El aplastamiento del hormigón en la losa y su fisuración, los efectos de rigidización post fisuración, la fricción de la interfaz y el comportamiento elasto-plástico de los conectores fueron tomados en consideración.Sustainability of buildings and public infrastructure is a relatively recent topic put into discussion by the engineering community. A solution to designing structures that have long-term durability and low maintenance requirements is to introduce new construction materials or to implement new structural systems. In this regard, fiber reinforced polymers (FRP) represent one of the novel solutions in the civil engineering field that offer promising results. To optimize the use of FRP shapes, researchers have proposed to form hybrid structural systems by combining the composite materials with conventional materials, such as concrete, in order to improve on the stiffness, ductility, and buckling resistance of single FRP members. However, due to the novelty and wide variety of hybrid elements, the technology demands further experimental testing to prove its viability. In addition, because there is a current lack of mandatory codes for the design of structures built with composite profiles and consequently FRP-concrete members, reliable predictive models have to be developed. Addressing the above-mentioned issues is essential in lessening the introduction of advanced composite materials in common types of public works and constructions. The present research aimed thus to study the structural performance of hybrid beams made of FRP pultruded profiles attached to concrete slabs by carrying an experimental, analytical, and numerical investigation. Since interface slip effects had been largely overlooked in the past, the thesis focused also on the influence of the connection flexibility over bending behavior. With respect to the developed experimental campaign, eight glass FRP-concrete hybrid beams with mechanical shear connectors were fabricated and their flexural behavior was assessed against that of equivalent reinforced concrete beams and single GFRP structural profiles. The variables of the research were the type of hybrid cross-section and the concrete strength class. The laboratory campaign was divided in two phases depending on the specific test setup configuration, and observations were made regarding the short-term behavior of the novel elements under positive bending moments. Previous to the experimental tests, a nondestructive characterization procedure was proposed for obtaining the elastic properties of the constitutive materials of hybrid members in a reduced amount of time, by using an analysis of the free vibration response. Overall, the bending tests have demonstrated the high structural efficiency of the hybrid beam solution and have underlined the importance of accounting for shear connection deformability. An analytical procedure was introduced for the design of FRP-concrete beams under short-term loading. Design equations for the serviceability and ultimate limit states were proposed in function of complete or partial shear interaction assumptions. The feasibility of using simplified formulas to quantify for interlayer slip effects was studied in evaluating deflections, flexural stiffness, bending capacities, normal and shear stress distributions. Due to the improved precision of the expressions that had considered the shear connection flexibility, the proposed analytical procedure was able to capture appropriately the structural behavior and performance of the specimens. Finally, referring to the numerical analyses, predictive finite element models capable of simulating the fundamental behavior of FRP-concrete beams with bolted joints were developed. The model that included material, contact, and geometry nonlinearities offered the best results in comparison with the experimental data and analytical estimations. Concrete slab crushing and cracking, tension stiffening effects, interface friction, and the elasto-plastic behavior of the shear connectors were all taken under consideration.
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ANDRADE, HEBER AUGUSTO COTARELLI DE. "IMPLEMENTATION OF NUMERICAL PROCEDURES FOR THE ANALYSIS OF DRAINING ELEMENTS IN SOILS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4301@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOEsta pesquisa visa o desenvolvimento de uma ferramenta numérica capaz de simular a inclusão de elementos drenantes em solos, sejam eles representados por drenos subhorizontais ou poços, constituindo sistemas de drenagem amplamente utilizado em estabilidade de encostas, túneis, escavações e outros. A implementação foi gerada nos programas de fluxo SWMS_2D e SWMS_3D (Simunek e outros, 1994). A formulação proposta considera a equação de fluxo do elemento drenante e a estratégia numérica de sua inclusão na equação de fluxo do solo pelo método dos elementos finitos. Algumas análises numéricas foram realizadas visando a validação do algoritmo. Para os poços foram analisados os casos confinados e não confinados e em regime permanente e transiente, comparando as soluções numéricas obtidas com as soluções analíticas de Theis (1935) (Freeze, 1979), para aqüífero confinado, e de Neumann (1975), para aqüífero não confinado. Para os drenos subhorizontais, propõe - se aqui uma metodologia de análise, levando em consideração os parâmetros hidráulicos e geométricos de um elemento de dreno. Sua aplicação atual não requer muito rigor e este estudo vem com a proposta de ser uma ferramenta geotécnica na fase de projeto de uma obra.
This research aims at the development of a numerical tool capable to simulating the inclusion of draining elements in soils. These elements are represented by subhorizontais drains or wells, constituting systems geotechnical widely used in stability of slopes, tunnels and other problems. The implementation was based in the finite elements programs of flow SWMS_2D and SWMS_3D (Simunek e outros, 1994). The proposed formulation considers the equation of flow of the draining element and the numerical strategy of its inclusion by using the method finite elements. A few numerical analyses were carried out aiming at the validation of the proposed algorithm. For the wells, the confined and unconfined cases and in permanent and flow transient conditions have been analyzed, comparing the obtained numerical solutions with the analytical one by Theis (1935) (Freeze, 1979), for water-bearing confined, and one by Neumann (1975), for water-bearing unconfined. For the subhorizontais drains, an analysis methodology is proposed here, taking in to consideration the hydraulical and geometric parameters of a drain element. In this case illustrative examples are presented. The implementation carried out is a simplified one but is should be adequate for the design of geotechnical structures.
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Cherif, Mohamed Raouf. "Theories et procedures numeriques visant a ameliorer l'efficacite du calcul par elements finis." Paris 6, 1986. http://www.theses.fr/1986PA066627.
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Le travail que nous presentons consiste a evaluer des theories et des procedures numeriques afin d'ameliorer le calcul par elements finis des problemes poses par les singularites geometriques (problemes numeriques de precision et de convergence). Dans la premiere partie, on a etudie les possibilites d'une modelisation plus fine (par rapport aux modelisations classiques) construite sur une formulation de second ordre permettant de pallier les problemes signales ci-dessus. Dans la deuxieme partie, on s'est interesse a developper des elements de raccordements differents en forme et en raffinement bases sur l'emploi d'une methode de transformation des matrices de rigidite. Dans la troisieme partie, on a teste une procedure de modification de la matrice de rigidite globale assemblee pour traiter les problemes de diversite de profils sur une meme structure standart. Dans la quatrieme partie, nous avons effectue des analyses theorique et numerique confrontees avec une analyse experimentale d'un modele industriel pratique d'une filiere a divers profils de filage en flexion
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Tatjana, Maravić. "Uticaj endodontske instrumentacije i restaurativnih procedura na biomehaničke karakteristike endodontski lečenih premolara." Phd thesis, Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, 2019. https://www.cris.uns.ac.rs/record.jsf?recordId=108805&source=NDLTD&language=en.
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Uvod. Usled kompromitovanja strukturnog integriteta, rekonstruktivne procedure na endodontski lečenim zubima moraju se veoma pažljivo isplanirati, pogotovo u specifičnoj grupi zuba kao što su premolari. U stomatološkoj naučnoj i stručnoj javnosti ne postoji usaglašen stav o tome koja endodontska instrumentacija i rekonstruktivna procedura primenjena u slučajevima ekstenzivnog gubitka zubne supstance predstavlja metodu izbora sa biomehaničkog aspekta. U okviru prezentovane doktorske disertacije ispitivan je uticaj varijacija u endodontskoj instrumentaciji i restaurativnim procedurama na promene naponskih stanja u zubnim tkivima i rekonstruktivnim materijalima kod premolara sa ekstenzivnim gubitkom zubne strukture. Metode. Osnovni 3D model je kreiran pomoću CT snimaka zdravog drugog gornjeg premolara u SolidWorks programu za modelovanje. Kreirano je 135 različitih modela, u kojima su metodom konačnih elemenata proračunati fon Mizesovi naponi u položaju maksimalne interkuspidacije pod dejstvom sile od 150 N. Statistička analiza je izvršena koristeći Opšti linearni model. Rezultati. Indirektne zubne rekonstrukcije imaju povoljniji uticaj na naponska stanja u zubnim tkivima. Ukoliko se koristi direktna restauracija, povoljniji su naponi u dentinu i gleđi ukoliko se redukuje palatinalna kvržca. Upotreba kočića uz ispun snižava napone u zubnim tkivima samo u slučaju MOD kaviteta. Naponi u dentinu su niži pri apikalnom terminusu 0,5 mm i instrumentaciji instrumentima manje veličine (kod modela sa kočićem i indirektnim nadoknadama). Uglavnom procedure koje su povoljne za napone u dentinu, nepovoljne su za napone u zubnoj nadoknadi i obratno. Zaključci. Kod opsežnih MOD kaviteta a samo ukoliko se ne redukuje visina palatinalne kvržice, preporučuje se upotreba kompozitnog kočića. Smanjenje površine zubnih tkiva u kojima su naponi visoki (iako su najviše vrednosti napona slične), moglo bi da utiče na dugotrajnost endodontski lečenih i rekonstruisanih zuba. Krući rekonstruktivni materijali povoljnije utiču na napone u zubnim tkivima biomehanički kompromitovanih endodontski lečenih zuba. Čini se da je optimalnije, u rekonstruktivnim rešenjima koja podrazumevaju upotrebu kočića, postaviti apikalni terminus bliže vrhu korena i koristiti instrumente srednje širine.Background. Restoration of an endodontically treated premolar with a wide and deep mesial-occlusal-distal (MOD) cavity is often complex due to biomechanical weakening of the tooth. There are no definitive recommendations on the optimal restoration in these cases. The aim of this study was to determine the effects of different endodontic and restorative procedures on von Mises stress values and distribution in dental tissues and restorative materials using finite element analysis (FEA). Methods. Based on CT scans of an second upper premolar, extracted for orthodontic reasons, 135 3D endodontically treated tooth models were created. Each model was subjected to a summary force of 150 N on the occlusal surface simulating the normal biting pattern and maximal von Mises stresses were calculated. Results. MODP cavity design seems to reduce von Mises stress values in dental tissues and P seems to transfer some of the stresses from dental tissues to the composite filling in the MOD cavity when direct restorations are used. Indirect restorations caused lower stresses within dentin. Apical terminus of 0.5 mm induces lower, while the terminus of 1.5 mm induces the highest stresses in dentin in models restored with direct composite and post. It seems that from the aspect of the tooth tissue, it is more recommended to use smaller endodontic instruments sizes. Conclusions. Stiffer restorative materials cause lower stresses in dentin of an endodontically treated structurally weakened tooth, and if a direct restoration is to be used, palatal cuspal reduction could be beneficial for the longevity of the tooth and the restoration. Further, in a wide and deep MOD cavity, without cuspal reduction, the use of a FRC post is recommended in order to reduce the stresses in the enamel and dentin. Moreover, it seems that it is beneficial for the stresses in the tooth tissue to place the apical terminus closer to the root apex as well as to use smaller size endodontic instruments.
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Del, Rio Simone. "Ricostruzione degli sforzi in elementi finiti di piastra." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amslaurea.unibo.it/117/.
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Nell’ambito dell’analisi computazionale delle strutture il metodo degli elementi finiti è probabilmente uno dei metodi numerici più efficaci ed impiegati. La semplicità dell’idea di base del metodo e la relativa facilità con cui può essere implementato in codici di calcolo hanno reso possibile l’applicazione di questa tecnica computazionale in diversi settori, non solo dell’ingegneria strutturale, ma in generale della matematica applicata. Ma, nonostante il
livello raggiunto dalle tecnologie ad elementi finiti sia già abbastanza elevato, per alcune applicazioni tipiche dell’ingegneria strutturale (problemi bidimensionali, analisi di lastre inflesse) le prestazioni fornite dagli elementi usualmente utilizzati, ovvero gli elementi di tipo compatibile, sono in effetti poco soddisfacenti. Vengono in aiuto perciò gli elementi finiti basati su formulazioni miste che da un lato presentano una più complessa formulazione, ma dall’altro consentono di prevenire alcuni problemi ricorrenti quali per esempio il fenomeno dello shear locking. Indipendentemente dai tipi di elementi finiti utilizzati, le quantità di interesse nell’ambito dell’ingegneria non sono gli spostamenti ma gli sforzi o più in generale le quantità derivate dagli spostamenti. Mentre i primi sono molto accurati, i secondi risultano discontinui e di qualità scadente.
A valle di un calcolo FEM, negli ultimi anni, hanno preso piede procedure di post-processing in grado, partendo dalla soluzione agli elementi finiti, di ricostruire lo sforzo all’interno di patch di elementi rendendo quest’ultimo più accurato. Tali procedure prendono il nome di Procedure di Ricostruzione (Recovery Based Approaches). Le procedure di ricostruzione qui utilizzate risultano essere la REP (Recovery by Equilibrium in Patches) e la RCP
(Recovery by Compatibility in Patches).
L’obbiettivo che ci si prefigge in questo lavoro è quello di applicare le procedure di ricostruzione ad un esempio di piastra, discretizzato con vari tipi di elementi finiti, mettendone in luce i vantaggi in termini di migliore accurattezza e di maggiore convergenza.
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Snyder, Luke Allen. "Sensitivity analysis of three assembly procedures for a bascule bridge fulcrum." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003243.
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Ivana, Kantardžić. "Uticaj restaurativnih procedura na biomehaničke karakteristike premolara – analiza realnog trodimenzionalnog modela zuba primenom metode konačnih elemenata." Phd thesis, Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=87352&source=NDLTD&language=en.
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Gubitak tvrdih zubnih struktura usled karijesne lezije, traume ili ekstenzivne preparacije dovodi do smanjenja otpornosti preostalih zubnih struktura na dejstvo sila prilikom žvakanja. Osnovni zadatak restaurativne procedure je da se ponovo uspostavi anatomo-morfološka funkcija zuba i da se preostale zdrave zubne strukture zaštite od nepovoljnog odgovora na dejstvo sila. Cilj doktorske disertacije bio je da se ispita uticaj različitih restaurativnih procedura na biomehaničke karakteristike premolara sa ekstenzivnim kavitetima. Materijal i metode: Trodimenzionalni model intaktnog drugog gornjeg premolara kreiran je u SolidWorks računarskom programu, na osnovu snimaka ekstrahovanog zuba primenom višeslojnog spiralnog kompjuterizovanog tomografa. Na osnovu ovog modela potom je kreirano ukupno 48 modela, koji su podeljeni u dve grupe: modeli vitalnog premolara sa MOD kavitetom (I grupa) i modeli premolara sa endodontski lečenim kanalom korena sa MOD kavitetom (II grupa). U svakoj grupi ispitivan je uticaj 4 vrste restaurativnog materijala (direktan kompozitni ispun, direktan kompozitni ispun sa smolom modifikovanim glas-jonomer cementom u vidu podloge, indirektan kompozitni ispun, keramički ispun), 3 dizajna preparacije kaviteta (bez skraćivanja kvržica, sa skraćivanjem palatinalne kvržice 2mm, sa skraćivanjem palatinalne i bukalne kvržice 2mm) i 2 širine istmusa (1/2 i 2/3 interkuspalnog razmaka). Primenom metode konačnih elemenata proračunate su vrednosti von Mises napona u zubnim strukturama i ispunu za sve modele pri dejstvu statičke sile od 200N. Rezultati: Dizajn preparacije kaviteta je pokazao najveći uticaj na vrednosti von Mises napona u zubnim strukturama. Pri tome, postupak skraćivanja palatinalne, kao i obe kvržice, doprineo je smanjenju vrednosti von Mises napona u gleđi na modelima obe grupe; dok je postupak skraćivanja bukalne i palatinalne kvržice doprineo smanjenju vrednosti von Mises napona u dentinu na modelima vitalnog premolara. U obe grupe, vrsta restaurativnog materijala pokazala je uticaj na vrednosti von Mises napona u gleđi, pri čemu je keramički ispun doveo do pojave napona značajno manjih vrednosti u odnosu na direktan i indirektan kompozitni ispun.Vrsta restaurativnog materijala je uticala i na vrednosti von Mises napona u dentinu, ali samo na modelima vitalnog premolara; pri tome su indirektni kompozitni i keramički ispun podjednako doprineli pojavi napona manjih vrednosti. Širina istmusa je uticala na vrednosti von Mises napona u gleđi i dentinu na modelima vitalnog premolara. Širina istmusa 1/2 interkuspalnog razmaka dovela je do pojave napona manjih vrednosti u gleđi, dok je širina istmusa 2/3 interkuspalnog razmaka dovela do pojave napona manjih vrednosti u dentinu.Loss of tooth structure from caries, trauma or extensive preparation decreases fracture resistance of tooth. The main goal of restorative procedure is to rebuild lost structures and to protect remaining tooth structures from unfavorable responses from masticatory forces. Aim of thesis was to investigate the influence of different restorative procedures on biomechanical properties of premolar with extensive cavities. Materials and Methods: Three dimensional model of intact maxillary second premolar, based on computerized tomography scan images of extracted tooth, was designed using SolidWorks software. Using this model, 48 models were designed and divided in two groups: models of vital premolars with MOD cavities (group I), and models of premolars with root canal treatment with MOD cavities (group II). In each group use of four restorative materials (direct composite resin restoration, direct composite resin restoration with resin modified glass-ionomer cement as base, indirect composite resin restoration, ceramic restoration), three cavity preparation designs (without cusp coverage, 2mm palatal cusp coverage, 2mm palatal and buccal cusp coverage) and two isthmus width (1/2 and 2/3 intercuspal width) were simulated. After applying static load of 200N, von Mises stresses in enamel, dentin and restoration were calculated using finite element analysis. Results: Cavity preparation design showed the most significant influence on von Mises stress values in tooth structures. Cusp coverage in general decreased stress values in enamel, while palatal and buccal cusp coverage decreased stress values in dentin only in group I. Restorative material affected stress values in enamel, were ceramic restoration contributed to minimal stress values. In dentin, indirect composite resin and ceramic restoration showed no difference in reducing von Mises stress values, but only for models in group I. Cavity isthmus width had influence on stress values in tooth structures only in group I. 1/2 isthmus width decreased stress values in enamel, while 2/3 isthmus width showed same effect in dentin. Conclusion: In order to provide optimal biomechanical characteristics of tooth structures, premolars with MOD cavity should be restored with ceramic overlay covering both palatal and buccal cusp.
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Osman, Emad Abd El-Moniem Mohamed. "Experimental, theoretical and finite element analysis of a reinforced earth retaining wall including compaction and construction procedures." Thesis, University of Glasgow, 1990. http://theses.gla.ac.uk/2820/.
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This thesis is concerned with an experimental and theoretical study of the behaviour of a reinforced earth retaining wall built on a rigid foundation, during and after construction with special attention paid to the effect of the compaction process. The theory and development of reinforced earth, four case histories, and tests on full scale models and small scale models related to the effects of compaction and current design methods have been reviewed with comments. The research work is tackled on two fronts: - Experimental model study. - Theoretical studies. 1) Experimental model study The model study, a three dimensional model, simulates a vertical reinforced earth retaining wall of height 6.0m with a model scale `10'. The model comprises an open fronted wooden box 1300mm long, 900mm wide and 700mm high, and the box contains the wall retaining 1200Kg of sand reinforced with aluminium foil strips 0.1mm thick attached to perspex facing panels of 150 x 150 x 18mm each. The sand bed in the model was formed using a sand spreader, dust extractor machine and a vibratory compaction device simulating the compaction plant in the field. Sixty six strain gauges, sixteen miniature pressure cells, which were developed and calibrated completely in the laboratory, and eight LVDTs were used to monitor the behaviour of the wall before, during and after compaction, under various uniform and variable compaction lengths and different methods of construction. Two methods of calibrating the density in the models were established, viz. temporary metal metal cylinders and permanent perspex cylinders. 2) Theoretical studies These were divided into two sections as follows: a - Theoretical study of compaction. b - Finite element method.
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Deirmendjian, Élisabeth. "La stratégie d'anticipation procédurale en matière civile." Thesis, Toulon, 2012. http://www.theses.fr/2012TOUL0068/document.
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La stratégie d’anticipation procédurale en matière civile permet d’effectuer un choix approprié entre les différentes règles existantes en fonction du but poursuivi. L’anticipation du procès et la stratégie au cœur de l’action dessinent en creux le champ de la liberté individuelle laissée au justiciable dans le procès civil. En anticipant la survenance du litige ou en envisageant les modalités de résolution de ce dernier, la technique contractuelle fait de l’évitement du recours juridictionnel une stratégie d’anticipation. Une fois le litige né, le choix d’agir en justice suppose l’évaluation des chances de succès de l’action par rapport au résultat escompté. Seront parfois préférés les modes amiables de règlement des différends, voire le recours à un juge privé en la personne de l’arbitre. Mais si l’action est diligentée, le justiciable devra nécessairement soulever un certain nombre de questions nécessaires à l’élaboration de la stratégie qu’il retiendra pour son affaire. Pour réduire l’aléa judiciaire, plusieurs paramètres doivent être pris en compte tels que l’évolution du droit, de la jurisprudence, la réaction de l’adversaire ainsi que l’office du juge. L’efficacité de la stratégie d’anticipation varie selon le degré de prévisibilité de ces différents éléments qui forment l’objet de cette étudeThe civil procedural assessment strategy allows for a proper choice between the various existing rules depending on the aim. The assessment of the trial and the strategy at the heart of the lawsuit sets aside the scope of individual liberty that the defendant is entitled to during the civil trial. During the assessment of the origin of the dispute or the consideration of the methods for resolving it, the contractual technique is a matter of avoiding judicial recourse as part of an assessment strategy. Once the litigation has been entered into, the choice of suing involves assessing the chance of success of the lawsuit compared to the expected result. Sometimes what is preferred is alternative dispute resolution methods, or even recourse to a private judge (arbitrator). But if a lawsuit is entered into, it will be necessary to provide the defendant with answers to a certain number of questions that are necessary for developing the strategy that he will use throughout the case. In order to reduce legal risk, several parameters must be taken into account, such as the current state of legislation, jurisprudence, and opponents’ responses as well as those of the Office of Justice. The effectiveness of the assessment strategy will vary depending on the degree of predictability of the different elements which form the subject of this study
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Bin, Mansor Idris. "Procedures and strategies in the translation into Malay of cultural elements of Rihlat Ibn Battuta." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540572.
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Eriksson, Anton. "Non-Linear strain paths in Sheet Metal Forming." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-21906.
Full textAbstract:
Today's automotive requirements have resulted in complex Sheet Metal Forming (SMF) processes of Sheet Metal (SM) with reduced formability, and thus it is crucial to be able to predict formability accurately to prevent material failure during SMF. Formability predictions today utilize Forming Limit Curves (FLC)s in Finite Element Analysis (FEA), but FLCs are not valid for the Non-Linear Strain Paths (NLSP)s generated during SMF. One purpose of this thesis is thus to increase the knowledge on FP handling NLSP, which was obtained through providing suggestions of failure models for handling NLSP effects, based upon literature on the subject. Generating NLSP experimentally is both time and material costly with the conventional method, thus the second purpose of this thesis was to increase the knowledge on test procedures for generating NLSP in SM. Based upon the findings of Chandramohan \cite{chandramohan_study_2021} five test procedures for generating NLSP were put forward, and the Nakajima test with modified punch geometry was chosen for further study. In this thesis, the NLSP characteristics of two modified punch geometries were evaluated by FEA performed using LS-DYNA. For the FEA three specimens with blank width of 50, 100 and 200 mm was used, and the anisotropic Barlat yld2000 was used as the material model. This material model was calibrated to material data of Mild steel CR4, Aluminium alloy AA6016, and Dual-phase steel DP800. The results for all materials showcased similar reacquiring general NLSP characteristics at the corners of the punch features, which are unfavorable positions when failure by necking is evaluated, and thus it was concluded that the tested punch geometries are not favorable and more development of the punch geometry is needed.Dagens fordonskrav, har lett till komplexa plåtformnings processer av plåtmaterial med reducerad formbarhet, och det är därför väsenligt att kunna förutsäga formbarhet noggrant för att förhindra materialbrott under plåtformning. Försträckning och brott förutses idag genom Formgränskurvor (FGK) i finita element analyser (FEA), men dessa gäller inte för icke-linjära töjningsvägar som uppkommer under plåtformning. Ett syfte av denna avhandling är därför att öka kunskapen kring modeller för att förutsäga formbarhet under icke-linjära töjningsbanors effekter, vilket uppnådes genom att presenteras förslag på brott modeller för att hantera de icke-linjära töjningsvägar baserade på literatur inom området. Att generera icke-linjära töjningsvägar experimentellt är både tids och materialkrävande med den konventionella metoden, således är det andra syftet av denna avhandling att öka kunskapen kring test metoder för att generera icke-linjär töjningsbvägar i plåt. Baserat på Chandramohans \cite{chandramohan_study_2021} resultat diskuteras fem test procedurer för att generera icke-linjära töjningsvägar, och Nakajima test med modifierad stämpelgeometri valdes för vidare studie. I denna avhandling studerades töjningsignaturen av två stämpelgeometrier med FEA i LS-DYNA. Till FEA:n användes tre ämnen med bredd av 50, 100 och 200mm, och anisotropiska Barlat yld2000 användes som materialmodell. Denna materialmodell kalibrerades mot experimentella mätvärden för mjukt stål CR4, Aluminiumlegering AA6016 och Stål DP800. Resultaten visade för alla material återkommande generella icke-linjära töjningsbanor enbart för hörnorna på stansgeometrierna, vilket är icke önskvärda positioner då brott pga. midjebildning utvärderas, och således drogs slutsatsen att nuvarande stansgeometri inte är gynnsam och ytterligare utveckling behövs.
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Castori, Giulia. "Interaction between axial force, shear and bending moment in reinforced concrete elements." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8519/.
Full textAbstract:
Il collasso di diverse colonne, caratterizzate da danneggiamenti simili, quali ampie fessure fortemente inclinate ad entrambe le estremità dell’elemento, lo schiacciamento del calcestruzzo e l’instabilità dei ferri longitudinali, ha portato ad interrogarsi riguardo gli effetti dell’interazione tra lo sforzo normale, il taglio ed il momento flettente.
Lo studio è iniziato con una ricerca bibliografica che ha evidenziato una sostanziale carenza nella trattazione dell’argomento.
Il problema è stato approcciato attraverso una ricerca di formule della scienza delle costruzioni, allo scopo di mettere in relazione lo sforzo assiale, il taglio ed il momento; la ricerca si è principalmente concentrata sulla teoria di Mohr.
In un primo momento è stata considerata l’interazione tra solo due componenti di sollecitazione: sforzo assiale e taglio. L’analisi ha condotto alla costruzione di un dominio elastico di taglio e sforzo assiale che, confrontato con il dominio della Modified Compression Field Theory, trovata tramite ricerca bibliografica, ha permesso di concludere che i risultati sono assolutamente paragonabili.
L’analisi si è poi orientata verso l’interazione tra sforzo assiale, taglio e momento flettente. Imponendo due criteri di rottura, il raggiungimento della resistenza a trazione ed a compressione del calcestruzzo, inserendo le componenti di sollecitazione tramite le formule di Navier e Jourawsky, sono state definite due formule che mettono in relazione le tre azioni e che, implementate nel software Matlab, hanno permesso la costruzione di un dominio tridimensionale. In questo caso non è stato possibile confrontare i risultati, non avendo la ricerca bibliografica mostrato niente di paragonabile.
Lo studio si è poi concentrato sullo sviluppo di una procedura che tenta di analizzare il comportamento di una sezione sottoposta a sforzo normale, taglio e momento: è stato sviluppato un modello a fibre della sezione nel tentativo di condurre un calcolo non lineare, corrispondente ad una sequenza di analisi lineari.
La procedura è stata applicata a casi reali di crollo, confermando l’avvenimento dei collassi.
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Agrawal, Ravi Prakash. "Using finite element analysis of retroreflective raised pavement markers to recommend testing procedures for simulating their field performance." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3730.
Full textAbstract:
Retroreflective Raised Pavement Markers (RRPMs) supplement other pavement
markings to provide guidance to road users. Previous research concerning durability of
the RRPMs suggests that their performance has been degrading over the years. One of
the main causes for underperformance of the RRPMs is the lack of appropriate
laboratory testing standards that can test the adequacy of the RRPMs to perform in field
conditions. There is a need to modify the existing standards or develop new testing
procedures that can better simulate field conditions. This requires identifying critical
locations and magnitudes of stresses inside the markers during the tire-marker impacts
that happen on roads.
The goal of this research was to identify critical magnitudes and locations of the
stresses in RRPMs during the tire-marker impacts by doing the finite element modeling
and simulation of the impacts, and use the information to recommend laboratory testing
procedures that could simulate real-world conditions. The researcher modeled and
simulated the tire-marker impacts using the finite element tools Hypermesh and LS DYNA. He calibrated the material properties of the marker models to improve the tiremarker
model.
Based on the tire-marker impact simulations, the researcher concluded that the
critical compressive stresses during impacts are located at the edge contacts of
retroreflective sides with the top surface. The critical stresses may also occur at lower
and upper corners of the marker. The other areas, especially the lower half of the marker,
had tensile stresses. Angle of impact was found to be a critical external variable that
affected the stresses inside the markers and the marker-pavement interface forces.
The researcher then modeled and simulated a few laboratory-testing procedures
that could simulate the field performance of the RRPMs. Based on these simulations, the
researcher recommended that the ASTM compression test for evaluation of RRPMs be
continued or a similar test be developed. He suggested development of one new test
(named as offset compression test) that could better replicate the field conditions. He
also recommended having a review of the ASTM flexural test.