After Deep Water Horizon platform accident, on Mexican gulf, 2010, offshore safety rules increase requirement levels for platforms and offshore wells around the world. In Brazil, to attend those requirements is very important in order to became Pre-Salt reservoir feasible, because its wells operate in higher pressures and flows than normal ones, making risks and failure consequences more severe, demanding more accurate studies about offshore rig platform critical safety systems. On this way, it was studied how to determine the required shear force to cut drilling pipes on shear ram blowout preventer systems, where shear force is one of the main mechanical loads suffered by SRBOP - shear ram BOP. Considering simple cutting blade geometries, results from real equipment cutting experiments and previous studies to create analytical and numerical models to predict this force. Where was taken on account the mechanics of pipe shearing as well as models of plasticity and failure of ductile materials, taking as reference empirical tube kneading equations, analytical cutting models and previous finite element models developed for this purpose. Presenting in the final results the comparison between the numerical and analytical models developed with the results of the experiments and predictions of the reference models.

This work aims to determinate the thermophysical properties of the naval steel ASTM A131 Gr. EH36 at low temperatures in order to enhancing the numerical models of structures subjected to accidental loads caused by cryogenic spill. For this purpose, the method of application of different heat flux intensities, which allows the simultaneous determination of the thermal conductivity ( ) and volumetric heat capacity ( ). The experimental apparatus consists of a resistive heater controlled by a power supply that generates a constant heat flux at the sample top surface. The bottom surface was isolated by expanded polystyrene plates and a thermocouple attached at the sample by capacitive discharge welding performs the temperature measurement. To calculate the temperature profile at the sample bottom temperature was used the finite difference method with implicit formulation. The square difference between the measured and calculated temperature was used as objective function and minimized through the BFGS (Broyden-Fletcher-Goldfarb-Shanno) method. The sensitivity analyses based on the scaled sensitivity coefficient and the experimental residue permits to verify the simultaneous optimization feasibility and the parameter convergence to a real value. Based on this analysis two heat flux intensities were required: one of an increased intensity, which enhances the scaled sensitivity of thermal conductivity, and one of a less intensity, which regulates the scaled sensitivity of volumetric heat capacity. The stainless steel AISI A304 was used to verify the effectiveness of the method, through a comparison between the optimized and the reference thermal properties. Based on the results of this work it can be affirmed that the method is able to determinate the thermophysical properties simultaneously with low experimental error.

Brazil has a vast historical, artistic and cultural heritage of the colonial era composed of buildings built mostly of masonry. In Salvador, today, part of this legacy is highly degraded, and restorative interventions are required to remain stable. There are several techniques of consolidation and/or structural rehabilitation that can be employed, among them the use of metallic structure. The purpose of this dissertation is to investigate the connection between a new, temporary or definitive metal structure and the old one, in solid brick masonry. The objective is to make a comparative analysis of the mechanical behavior of three types of metallic connectors (mechanical, chemical and with grout) obtained as a result of experimental pull-out tests with that of computational modeling and that acquired by analytical formulations present in the literature reference. From these studies, it will be possible to identify the most appropriate type of connection in restorative interventions using metal structures.

In this work, we have the study of reinforcement of webs of box girder bridges in prestressed concrete using carbon fiber reinforced polymer (CFRP). The objective of this work is to propose analytical criteria for the reinforcement of webs of box girder bridges in prestressed concrete using CFRP. The analytical criteria were developed based on the international standards ACI 440 (2017) and CEB-FIP, Bullentin 14 (2001), adapted to the requirements of the Brazilian standard NBR 6118 (2014) and to the sizing of box girder. To do this, carry out the case study of the Joseph Wagner Viaduct, designed in box girder and using TB-360 vehicle of Brazilian standard NB-6 (1960), and needs to be adapted to TB-450 vehicle of current standard, NBR 7188 (2013). For this case study, the National Department of Transport Infrastructure give the viaduct rehabilitation project, provided important information related to the geometry, material properties and steel area of some sections of the beam. For analysis of the increase of loads, the viaduct was modeled in finite elements, using the TB-360 and TB-450 vehicles. From the results, it was verified the need to reinforce the shear force, torsion and transverse flexion of the webs. For the beam section that required reinforcement, it was designed the reinforcement using the analytical criteria proposed in this dissertation. The developed criteria presented satisfactory results and indicated important points that should be taken into account in bridge rehabilitation projects and in reinforcement projects (longitudinal and transverse) of concrete beams using CFRP. At the end of the dissertation, recommendations and suggestions related to sizing, design and adaptations of the international normative requirements with the Brazilian standards are addressed.

This research studies the Finite Element Method applied to the non linear analysis of the Timoshenko-Vlasov beam. Initially, the objective is to investigate the non linear formulation for tridimensional beams to simulate reticulated structures, taking into account the cross section warping effects as problem variables. A software will be developed using the C programming language for the structural analysis of the beams mentioned. The non linear constitutive equations utilized are based on Simo-Ciarlet material law. Several numerical examples are generated from the developed software to ilustrate the theory's validity, and following that, the obtained results are compared to similar problems modeled on the ANSYS comercial software, to evaluate the result's proximity. The obtained results suggest that the used formulations present satisfatory performance for the analysed examples.

Industrial valves are complexly manufactured products, featuring a wide variety of design combinations involving different materials, geometric shapes, seals and mechanical drive assemblies. With regard to the design of the body and bonnet of the equipment, NBR 15827 reference the American Standard ASME Section VIII Division 2. The elastic analyzes currently available in the ASME standard, have limitations in their use. These limitations are mainly associated with the need of Stress Linearization method when using solid finite elements in the modeling of complex geometry and thick wall equipment. When such limitations are identified, the use of inelastic limit load and elastoplastic analysis methods is recommended. The guidelines for inelastic analysis, presented in ASME Section VIII Division 2 Part 5, are global and do not address the particularities that should be observed in the formulation of the model and interpretation of the results obtained. Another point of uncertainty is related to the choice of using limit load or elastoplastic analysis, whether one can be used instead of the other, if they are complementary or if the application of these methods also has some limitation. In this work, the main computational methods used for the project development by analysis of the body and bonnet of industrial valves were evaluated, with the objective of identifying the applicability and limitations of these methods, from a critical evaluation of the recommendations present in the codes and literature. As a result, it was found that the use of Stress Linearization for thick-walled vessels may cause risks to the equipment design, especially regarding the interpretation of the peak stress values obtained in the analyzes. In the evaluation of inelastic methods, it was found that such methods, are able to bring more rationality to the design of the valve body and bonnet. In this context, a comparison was also made between the results obtained in the limit load analysis and the elastoplastic analysis, showing that the choice of one of these methods should be made, not only to achieve higher operating pressure values, but also to assess the service operability, especially regarding the deformations obtained in these analysis.

ERA was developed in the aerospace engineering environment in the 1980s to enable the identification of complex state-space systems. To use ERA an impulsive input and measurements of the system outputs for Hankel matrix composition are required. The singular value decomposition of this matrix allows the identification of the matrices that govern the system. The difficulty in working with impulsive inputs in real systems and the need to reduce computational efforts in low damped systems motivated the development of ERA/OKID. This methodology is a derivation of the ERA theory by applying a state observer filter or Kalman filter. These two methodologies have been used in the field of control engineering to allow the identification of complex systems and the development of optimal controllers, since the systems are identified in state space and this representation is essential in this area of knowledge. However, the tools show great potential to aid the modal analysis of systems, since one of the possibilities, after identifying the minimum system realization, is to obtain the modal parameters - natural frequency and damping factor, for example. To highlight these possibilities, the work presents the basic concepts of systems identification, the theories for the development of ERA and ERA/OKID and systems analysis by modal superposition. In addition, the ERA/OKID algorithm is applied to a two different experimental systems, namely: a classic 2 DOF mechanical system and a composite material beam. The results obtained for both were very interesting

Advanced models of calculation can be used to solve dierential equations that
characterize several engineering problems, such as problems of stress and strain analysis
and dynamics of metallic structures. Among these models, the Finite Element Method
(MEF), a numerical tool widely used, stands out due to the versatility of its computational
routines, being applied in practically all branches of engineering. The purpose of this work
is to demonstrate a mathematical model that satisfactorily describes the dynamic behavior
of metallic structures through the modal analysis of the natural vibration and amplitude
of frequencies, with a tangent scope to the nite element modeling technique. In this way,
we elaborate mathematical models entangled by the boundary conditions and properties
of the material of the structure under study. Such analysis refers to the study of a rotating
machine base subjected to dynamic loads, generated by the load transmitted from the
machine to the base. Models are created so that they faithfully simulate the geometric
distortions of the structure at vibrational levels. Although the various structural models
have particular characteristics, a computational routine is elaborated through the Scilab
software for calculation of natural frequencies of vibration, as well as vibratory amplitudes
in structures, such as machine bases, through MEF, contemplating the vast eld of existing
structural variants. Finally, the most critical points along the structure are determined
by the analysis of natural frequencies, mapping the resonance frequencies, as well as the
amplitude of the critical points and their safety coecient. Nevertheless, the results of
the numerical analysis of vibrations re ect well the distortions envisaged for structure, as
they are consonants with the amplitude values and natural frequencies calculated through
commercial software. So that, the FRF functions and graphs of displacement of the
structure translate well the estimated behavior for Foundation dynamics exposed to rotary
imbalance forces. Thus demonstrating the high eciency of the MEF in the solution
of problems in the structural area, the example of the dynamic's analysis of metallic
structures.

In this research the theoretical basis on the formulation of the problem of mechanical contact with friction for three-dimensional solids is presented, based on the mechanics of the continuum, the study of the nonlinear dynamics and its applications in the study of mechanical contact in the regime of large deformations. The formulation of the mechanics of the solids using the weak form is developed, obtaining the balance equilibrium equation of the moments, by the energy equation model of a Neo-Hookian material with hyperelastic properties. The Lagrangian Increased method is applied to the numerical solution of the contact problem and, in addition, the B-Spline contact element is substituted for the Lagrangian contact element, aiming at the use of a smooth and curved surface obtained from of the master surface softened by the B-Spline curve. Initially, a mechanical contact program in Programming Language C is implemented using the tetrahedral finite element replacing the hexahedral element. Next, we proceed with the study of the dynamics of the structures, developing a dynamic analysis for the mechanical contact. To complete, the algorithm of the dynamic analysis of the mechanical contact is developed and implemented in the computational code. The Newmark Method is used in the time integration for the dynamic analysis. At the end of the work, modeling of examples is presented, analyzing the effect of mechanical contact with dynamics between deformable bodies.