The advancement of the structural steel manufacturing industry has led to the recent emergence of steel members with Elliptical Hollow Sections (EHS) and Semi Elliptical Hollow Sections (SEHS). Although these sections are gaining popularity among architects, the lack of design guidelines specifically tailored towards these sections inhibits their efficient structural use. Within this context, this thesis provides several steps towards the development of such guidelines. A review of the manufacturing process of hot-rolled steel sections is conducted with emphasis on hollow structural sections. The main factors affecting the formation of residual stresses during cooling of the sections are discussed. Lower bound plastic interaction relations for EHS subjected to combinations of axial force, bi-axial bending moments and torsion are then derived. The formulation is based on the lower bound theorem of plasticity and the maximum distortional energy density yield criterion. Its applicability for conducting the cross-sectional interaction check in structural steel design problems is illustrated through a practical example. A simplified and conservative interaction equation is then proposed based on curve fitting of the results of the lower bound solution. Upper bound interaction relations are next developed for EHS subjected to combinations of axial force, bi-axial bending moments, torsion and bimoments. The formulation is based on kinematically admissible strain fields within the context of the upper bound theorem of plasticity. The interaction relations derived successfully capture the effect of confining radial strains present at welded end sections, as well as sections that are free to deform in the radial direction away from end welded sections. An iterative solution technique is developed to solve the resulting highly non-linear system of interaction relations. The effects of residual stresses and initial imperfections on axial compressive resistance of hot-rolled EHS are then incorporated into the lower bound interaction relations. Towards that goal, the thermo-mechanical properties of steel were extracted from the literature. A thermo-mechanical finite element model was developed for prediction of residual stresses in rolled sections. The validity of the model was assessed by comparison against residual stress measurements available in the literature. The model is then applied to predict the residual stresses in hot-rolled EHS. A series of geometric and material nonlinear finite element analyses is conducted on columns of EHS sections. The analyses include predicted residual stresses and initial out-of-straightness imperfections in order to determine the inelastic buckling capacity of EHS members and generate column curves for EHS sections. The column curves are subsequently compared to those based on Canadian, American and European design codes. Two column curve equations are proposed in a format similar to that of the Canadian Standards for buckling about major and minor axes. The column curves were subsequently combined with the interaction relations developed to provide design rules for EHS members under combined loads. The last contribution of the thesis provides a formulation of lower bound interaction relations for SEHS subject to combinations of axial force, bi-axial bending moments and torsion. An iterative scheme for solving the parametric form of the interaction relations is developed and a grid of admissible stress resultant combinations is generated. A series of trial functions are fitted to the grid of internal force combinations and two simplified and conservative interaction equations are proposed.

La part du travail dans le revenu national a connu des variations considérables en Europe continentale. La recherche empirique et théorique suggère que l'évolution du marché du travail et les imperfections de celui-ci peuvent en partie expliquer ce phénomène. Ce mémoire analyse de manière empirique et théorique le rôle des imperfections du marché du capital dans la détermination de la distribution du revenu national. Nous utilisons des méthodes de régression panel et de régression panel dynamique pour un pool incluant les principaux pays de l'OCDE. La régression tient compte des indicateurs du marché du capital, des facteurs provenant du marché du travail et des indicateurs macroéconomiques. Les résultats indiquent que l'intermédiation financière est négativement corrélée avec la part du travail, alors que l'inflation a des effets positifs. En outre, nous utilisons un modèle d'équilibre général simple pour retracer les effets des imperfections dans le marché financier sur les parts des facteurs. Les simulations du modèle soutiennent nos résultats empiriques. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Imperfections du marché du capital, Revenu national, La part du travail, Inflation.

Cette thèse comporte trois volets dont le thème commun est la présence d'imperfections sur le marché du capital. Le premier, en supposant que les firmes doivent financer une part de leur coûts de recrutement sur des marchés financiers imparfaits, réconcilie le modèle de furetage et d'appariement sur le marché du travail de Mortensen-Pissarides avec les données macroéconomiques. En particulier, les postes vacants et la tension sur le marché du travail sont à la fois très volatiles et leur ajustement suite à des chocs de productivité est progressif. Lorsque la prime sur le financement externe se comprime durant une expansion, et de manière progressive dû à l'accumulation de liquidités par les firmes, l'incitation à recruter pour un bénéfice espéré donné d'un nouvel employé est plus forte. Ceci génère un mécanisme de propagation suffisamment puissant pour reconcilier le modèle avec les données. Une extension à des séparations d'emploi endogènes préserve le mécanisme de propagation du modèle tout en lui permettant d'être cohérent avec certaines propriétés des flux de travailleurs sur le cycle. Le second documente en premier l'existence de phénomènes de congestion dans l'allocation du capital physique similaires à ce qui est observé sur le marché du travail, et étudie dans un modèle d'équilibre général quantitatif ces effets pour la propagation de chocs technologiques et, donc, pour l'étude des fluctuations conjoncturelles. La calibration du modèle sur les flux de capitaux mesurés au niveau des firmes mène à la conclusion que ces effets sont négligeables. L'introduction de liquidation du capital des firmes faisant banqueroute ne change rien à cette conclusion car les flux concernés par cette réallocation de capital sont trop petits. Le dernier volet de cette thèse s'écarte du cadre d'une économie fermée. Une caractéristique de l'investissement direct étranger que la théorie économique a du mal à réconcilier est le fait que, en période d'expansion, les flux d'investissement rentrant dans une économie d'accueil et les flux d'investissement de cette même économie vers l'étranger augmentent ensembles. En imposant des frictions dans l'allocation du capital à des établissements à l'étranger. avec la possibilité de fermer ces établissements pour réallouer ailleurs le capital qui y était engagé, un modèle dynamique à deux pays devient cohérent avec l'observation empirique sur les flux d'investissements directs. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Imperfections sur le marché du capital et du travail, Cycle conjoncturel.

The advancement of the structural steel manufacturing industry has led to the recent emergence of steel members with Elliptical Hollow Sections (EHS) and Semi Elliptical Hollow Sections (SEHS). Although these sections are gaining popularity among architects, the lack of design guidelines specifically tailored towards these sections inhibits their efficient structural use. Within this context, this thesis provides several steps towards the development of such guidelines. A review of the manufacturing process of hot-rolled steel sections is conducted with emphasis on hollow structural sections. The main factors affecting the formation of residual stresses during cooling of the sections are discussed. Lower bound plastic interaction relations for EHS subjected to combinations of axial force, bi-axial bending moments and torsion are then derived. The formulation is based on the lower bound theorem of plasticity and the maximum distortional energy density yield criterion. Its applicability for conducting the cross-sectional interaction check in structural steel design problems is illustrated through a practical example. A simplified and conservative interaction equation is then proposed based on curve fitting of the results of the lower bound solution. Upper bound interaction relations are next developed for EHS subjected to combinations of axial force, bi-axial bending moments, torsion and bimoments. The formulation is based on kinematically admissible strain fields within the context of the upper bound theorem of plasticity. The interaction relations derived successfully capture the effect of confining radial strains present at welded end sections, as well as sections that are free to deform in the radial direction away from end welded sections. An iterative solution technique is developed to solve the resulting highly non-linear system of interaction relations. The effects of residual stresses and initial imperfections on axial compressive resistance of hot-rolled EHS are then incorporated into the lower bound interaction relations. Towards that goal, the thermo-mechanical properties of steel were extracted from the literature. A thermo-mechanical finite element model was developed for prediction of residual stresses in rolled sections. The validity of the model was assessed by comparison against residual stress measurements available in the literature. The model is then applied to predict the residual stresses in hot-rolled EHS. A series of geometric and material nonlinear finite element analyses is conducted on columns of EHS sections. The analyses include predicted residual stresses and initial out-of-straightness imperfections in order to determine the inelastic buckling capacity of EHS members and generate column curves for EHS sections. The column curves are subsequently compared to those based on Canadian, American and European design codes. Two column curve equations are proposed in a format similar to that of the Canadian Standards for buckling about major and minor axes. The column curves were subsequently combined with the interaction relations developed to provide design rules for EHS members under combined loads. The last contribution of the thesis provides a formulation of lower bound interaction relations for SEHS subject to combinations of axial force, bi-axial bending moments and torsion. An iterative scheme for solving the parametric form of the interaction relations is developed and a grid of admissible stress resultant combinations is generated. A series of trial functions are fitted to the grid of internal force combinations and two simplified and conservative interaction equations are proposed.

1 ABSTRACT Procedural requirements of civil proceedings My thesis deals with the issues of procedural requirements of civil proceedings, that are sometimes termed also as requirements of proceedings. This term refers to the legal institute, that creates the legal framework for realization of the right to the judicial protection, because the fulfillment of these statutory requirements is one of the fundamental assumptions for hearing of the case and for the issuance of decision in the civil proceedings. Systematically my work is divided into two parts, namely into the general part and the special part. These two parts in total consists of seven chapters. Particular chapters are subsequently divided into the subchapters and each of them into the sections. While the general part consisting of the first three chapters concerns with the general view on the issues of procedural requirements, remaining four chapters of the special part deal with the particular procedural requirements in more detail. The first chapter aims to define as precisely as possible the term of procedural requirements and also potential discrepancies in its interpretation. It involves also the fundamental classification of procedural requirements. Chapter no. 2 analyses the research of procedural requirements, that occurs at any time during...

The advancement of the structural steel manufacturing industry has led to the recent emergence of steel members with Elliptical Hollow Sections (EHS) and Semi Elliptical Hollow Sections (SEHS). Although these sections are gaining popularity among architects, the lack of design guidelines specifically tailored towards these sections inhibits their efficient structural use. Within this context, this thesis provides several steps towards the development of such guidelines. A review of the manufacturing process of hot-rolled steel sections is conducted with emphasis on hollow structural sections. The main factors affecting the formation of residual stresses during cooling of the sections are discussed. Lower bound plastic interaction relations for EHS subjected to combinations of axial force, bi-axial bending moments and torsion are then derived. The formulation is based on the lower bound theorem of plasticity and the maximum distortional energy density yield criterion. Its applicability for conducting the cross-sectional interaction check in structural steel design problems is illustrated through a practical example. A simplified and conservative interaction equation is then proposed based on curve fitting of the results of the lower bound solution. Upper bound interaction relations are next developed for EHS subjected to combinations of axial force, bi-axial bending moments, torsion and bimoments. The formulation is based on kinematically admissible strain fields within the context of the upper bound theorem of plasticity. The interaction relations derived successfully capture the effect of confining radial strains present at welded end sections, as well as sections that are free to deform in the radial direction away from end welded sections. An iterative solution technique is developed to solve the resulting highly non-linear system of interaction relations. The effects of residual stresses and initial imperfections on axial compressive resistance of hot-rolled EHS are then incorporated into the lower bound interaction relations. Towards that goal, the thermo-mechanical properties of steel were extracted from the literature. A thermo-mechanical finite element model was developed for prediction of residual stresses in rolled sections. The validity of the model was assessed by comparison against residual stress measurements available in the literature. The model is then applied to predict the residual stresses in hot-rolled EHS. A series of geometric and material nonlinear finite element analyses is conducted on columns of EHS sections. The analyses include predicted residual stresses and initial out-of-straightness imperfections in order to determine the inelastic buckling capacity of EHS members and generate column curves for EHS sections. The column curves are subsequently compared to those based on Canadian, American and European design codes. Two column curve equations are proposed in a format similar to that of the Canadian Standards for buckling about major and minor axes. The column curves were subsequently combined with the interaction relations developed to provide design rules for EHS members under combined loads. The last contribution of the thesis provides a formulation of lower bound interaction relations for SEHS subject to combinations of axial force, bi-axial bending moments and torsion. An iterative scheme for solving the parametric form of the interaction relations is developed and a grid of admissible stress resultant combinations is generated. A series of trial functions are fitted to the grid of internal force combinations and two simplified and conservative interaction equations are proposed.

Interfacial mechanical properties of adhesive joints are very crucial in board applications, including composites, multilayer structures, and biomedical devices. Establishing traction-separation (T-S) relations for interfacial adhesion can evaluate mechanical and structural reliability, robustness, and failure criteria. Due to the short range of interfacial adhesion such as micro to nanoscale, accurate measurements of T-S relations remain challenging. The advent of machine learning (ML) became a promising tool to predict materials behaviors and establish data-driven mechanical models. In this study, we integrated a state-of-the-art ML method, finite element analysis (FEA), and standard experiments to develop data-driven models for characterizing the interfacial mechanical properties precisely. Macroscale force-displacement curves are derived from FEA with incorporation of double cantilever beam tests to generate the dataset for ML model. The eXtreme Gradient Boosting (XGBoost) multi-output regressions and classifier models are used to determine T-S relations with R2 score of 98.8% and locate imperfections at the interface with accuracy of around 80.8%. The outcome of the XGBoost models demonstrated accurate predictions and fast calculation speed, outperforming several other ML methods. Using 3D printed double cantilever beam specimens, the performance of the ML models is validated experimentally for different materials. Furthermore, a XGBoost model-based package is designed to obtain different adhesive materials T-S relations without creating a database or training a model.

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The human hand, in building as in art, has left its impression on all the earliest forms of architecture. Its mark has been one of imperfection, variation, and uniqueness, and with these traits the personification of something innately human. This character, instilled into any work, immortalizes the idiosyncrasies descriptive of its creator. Rather than viewed as anachronism, inculcating the human component, "manufactum", into modern design reacquaints us with our own capricious temperaments. As powerful tools of the contemporary world heighten our faculty for exactitude, the prudence remains as to whether and when it is appropriate to do so. / Master of Architecture

A computationally efficient procedure, NLPANOPT, is developed for the preliminary design of minimum-weight thin-walled stiffened composite panels loaded in uniaxial compression based on a geometrically nonlinear analysis. An approximate, semi-analytical nonlinear analysis code, NLPAN, which requires buckling eigenfunction information from the buckling analysis code, VIPASA, is linked with the optimization code ADS. A blade-stiffened and T-stiffened panel are designed for specified loads using NLPANOPT for postbuckling response and PASCO for buckling-critical response. Comparisons of panel weight and imperfection sensitivity between the NLPANOPT designs and PASCO designs are presented. In general, the designs obtained with NLPANOPT are lighter and less imperfection sensitive than the designs obtained with PASCO. The nonlinear analysis allows for a more accurate prediction of the true strength of the stiffened structure, by accounting for postbuckling strength and modal interaction. The effect of laminate stacking sequence is also investigated. The current design procedure requires the stacking sequence to be prescribed, proving to be a limitation in the design procedure. / Master of Science