METAL BUILDINGS

Author: MORENO REVILLA JESÚS.
Year: 2005.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S. DE INGENIEROS DE CAMINOS, CANALES Y PUERTOS.
Place of preparation: E.T.S. DE INGENIEROS DE CAMINOS, CANALES Y PUERTOS.

Summary: Many structures built with iron pudelado or forged steel during the nineteenth century and early XX still in use. The current charges do exist and damage assessments necessary structural integrity to extend its useful life, adapt their use and establishing monitoring programs and maintenance. The analysis of this type made so far are recent and believe that the damaged component of a structural element roblonada does not interact with the rest, although the unions roblonadas are the vehicle of this interaction. This thesis presents a methodology for evaluating the structural integrity of beams roblonadas old, which takes into account the interaction between components. One of his contributions is to develop an analytical method for calculating the stress intensity factor in common component beams fissured. The determination of this factor allows the application of critera shearing fragile and prediccióp of life to fatigue. The values are shown differences sutanciales when no one takes into account the interaction between components. Differences have particular impact on the predictions of fatigue life, and they relive that the forces transmitted by unions roblonadas arising from the interplay reach concentrations capable of causing failure of joints in anticipation of the fracture of the component fissured. The literature study was inconclusive as to the fragility of steel and wrought iron pudelado employed in the construction of the beams roblonadas old, nor in terms of its contribution to the resistance of unions roblonadas. Because of this thesis includes a chapter devoted to two experimental materials prcedentes of Spaniards old metal bridges. The purpose of this experimental work is to determine the resistance of the two materials to crushing unions roblonadas and measure their tencidad fracture to comporbar whether sufficient application of the criterion of brittle fracture analysis integrity esturctural or if it is necessary to resort to criteria shearing ductile. Although the shortage of sample material available has conditioned seriously testing program, it has only been possible to meet expectations but that the two materials have been characterized chemical and microstructural mechanically. The test results have provided the values of resistance capabilities required to develop criteria for judgment because of the tearing of the fissure and ductile failure due to the collapse of the unions roblonadas (shear roblones, depletion sections net and crushing taladors) . The values for the level of solicitation has been obtained by numerically models elastoplásticos elements finotos of the beam complete. The injury-free components, the component fissured and unions roblonadas. With these models and have determined the integral J of the beam roblonada and forces tansmitidas by unions roblonadas depending on the size and level of fissure solicitation. The high cost of these determinations numerical computational has led to the search procedures alternatiovos, having successfully explored the estimation method proposed by the integral J EPRI (Electric Power Research Institute). Finally, the criteria set for the various possible fault has built a diagram of structural integrity that confirms the possibility that the failure of unions roblonadas anticipating the breaking of the component fissured. Comparing this figure with which it is applied only criterion fracture of the component Fissured without considering the effect of the forces of interaction with other components has allowed excessive conservatism note that this procedure can be followed.

Author: PRADO TAMARGO JOSE RAMON.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: CAMPUS DE VIESQUES DE GIJON.
Place of preparation: DPTO. CONSTRUCCION E INGENIERIA DE FABRICACION.

Summary: The work presented as a doctoral thesis entitled System design, optimization and calculating machines continued maintenance by the finite element method for a doctorate D. Jose Ramon Prado Tamargo, we believe that it meets the requirements for their public presentation. As Directors of the work we emphasize the most important aspects that are reflected in the same First, highlight the fact that it is a complete compendium for applying numerical simulation techniques to the study of complex machinery and equipment continued maintenance. Machinery maintenance continuous presented the peculiarity of being formed by large structures to be moved each other to get the operation of the elements that permit the passage of materials (food), bringing its analysis is particularly complex as a result of the different positions to be taken by these structural elements, the large number of requests that are different from those submitted find and difficult geometry that these elements presented in reality, with the emergence of local phenomena error by bump, plasticity, and so on. Therefore, the detailed study of many real cases addressed in the thesis, as well as the methodology regarding the influence of the factors involved in the design of such machines, allowing the reader to get a sense of current possibilities of the simulation numerical under different perspectives, such as static analysis, nonlinear, plasticity, contacts and large deformation, showing the advantages, disadvantages and scope of each procedure. Of the importance and complexity of the work, we highlight some of the teams analyzed, such as tubular conveyor band, which have been published in the journal Mathematical and Computer Modeling, under the title Non-linear analysis and warping of tubular pipe conveyor by the finite element method. Therefore, we value highly the originality of the thesis, since the honoree has done a very comprehensive study of the methods of design, calculation and optimization of complex structures ongoing maintenance through the practical application of the finite element method.

Author: PRADO TAMARGO JOSE RAMÓN.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: SALA DE JUNTAS DEL MODULO 7 DEL EDIFICIO DE LAS SEDES DEPARTAMENTALES DEL CAMPUS DE VIESQUES.
Place of preparation: DPTO. CONSTRUCCIÓN E INGENIERIA DE FABRICACÓN.

Summary: The work presented as a doctoral thesis, we believe that it meets the requirements for their public presentation. As Directors of the work we emphasize the most important aspects that are reflected in it. First, highlight the fact that it is a complete compendium for applying numerical simulation techniques to the study of complex machinery and equipment continued maintenance. Machinery maintenance continuous presented the peculiarity of being formed by large structures to be moved each other to get the operation of the elements that permit the passage of materials (food), bringing its analysis is particularly complex as a result of the different positions to be taken by these structural elements, the large number of solicitations other than those who are subjected and the difficult geometry that these elements presented in reality, with the emergence of local phenomena error by bump, plasticity, and so on. Therefore, the detailed study of many real cases addressed in the thesis, as well as the methodology regarding the influence of the factors involved in the design of such machines, allowing the reader to get a sense of current possibilities of the simulation numerical under different perspectives, such as static analysis, nonlinear, plasticity, contacts and large deformation, showing the advantages, disadvantages and scope of each procedure. Of the importance and complexity of the work, we highlight some of the teams analyzed, such as tubular conveyor band, which have been published in the journal Mathematical and Computer Modellin, under the title Non-linear analysis and warping of tubular pipe conveyor by the finite element method. Therefore, we value highly the originality of the thesis, guarded by the honoree has done a very comprehensive study of the methods of design, calculation and optimization of complex structures continued maintenance by applying the finite element method.

Author: GUARDIOLA VÍLLORA ARIANNA PAOLA.
Year: 2006.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Universidad Politécnica de Valencia.
Place of preparation: Universidad Politécnica de Valencia.

Summary: Consider behavior semi-rígido for unions can reduce the size of the beams on the settlement articulated, and that possess a certain stiffness in bending when center vain decreases. On the other hand, when it comes to unions not rigidizadas, the cost to implement them is considerably lower than the rigid. Despite the advantages of such unions are not used in practice. Until a few years ago because the implementing rules included only criteria to check their resistance, and more recently because, despite the annexed J Eurocódigo 3 allows, beginning with its geometry, determine the strength and stiffness of joints semi - rigid, it does not provide an action strategy for the design of arcades with such knots. In order to establish it, and considering that the maximum reduction in the size of the beams is rigid structures knots, this thesis raises explore possibilities of design practices that offer those unions not rigidizadas with behavior as close as possible to the rigid (solder joints with direct perimeter and bolted joints with extended front plate). With this object has been estimated more than 1500 porches building designed with such unions considering their actual stiffness (obtained by the method of components) modeling their behavior as possible idealizations diagram Momento-Rotación which sets the reference standard, by analyzing their influence on the response of the structure, and verify their resistance to different lengths of beams and supports and different numbers of plants and vain, comparing the results with those of the same gates designed with rigid or articulated joints, so to obtain guidelines for design and range of validity of the same.