Introdução à dinâmica de rotação clássica

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Análise experimental da conexão entre blocos segmentais e geogrelha de PVA

The test system connection segmental blocks and geogrids at the Department of Civil Engineering, UNESP - Guaratinguetá order to verify the strength of the connection system when subjected to different confining stresses. The present work aims to demonstrate the procedures for carrying out the test as well as the placement of concrete blocks. Were analyzed two ways of placing the blocks in the press. An entire block and two halves in the first layer, named position 12, compared to a different format, two entire blocks in the first layer, named position 21; also geogrids: single and double layer. From the data obtained for the peak strength of 20 tests it was possible to obtain the envelopes break in the connection for single and double layer. In 2011, the size of the concrete block used in the test was lower when compared with previous years. What resulted in significant decreases in the loss of connection in single layer and it was noted that there was no decrease in the strength of connection in the double-layer tests, despite the smaller area of contact between the block and geogrid. It is concluded that, through the analysis of geogrids after running the test, the concrete block is responsible for theforce that allows the movement of the geogrid due to the force from the ground

Estudo do fenômeno de instabilidade de estruturas cilíndricas de paredes finas submetidas ao carregamento de pressão externa

Thin walled cylindrical shells are widely used in many areas of industry, including civil, mechanical, nuclear, marine, petroleum and aerospace engineering. The wide application of thin cylindrical shells and the importance of instability phenomenon are the motivation basis to this study, since these factors have a great importance in engineering projects. It is presented a detailed study about the instability of cylindrical shells based on theoretical calculation, which results are compared with finite elements method calculation. The loading and boundary conditions analyzed are based on the most common types verified in real engineering projects and refer respectively to lateral (external) pressure and cylinders with simply supported edges. The calculation based on the finite elements method was executed with ANSYS 13.0 software. The results obtained with this calculation are in good agreement with the analytical theory presented in the technical note NACA No 1341 (BATDORF, 1947) considering a wide range of applicability. On the other hand, the analytical method presented in the book Theory of Elastic Stability (TIMOSHENKO; GERE, 1936) has a very restrict applicability and has presented considerable deviations in a great sort of the analyzed cases

Estudo da fluidodinâmica de uma mistura de sólidos em um leito fluidizado gás-sólido

Fluidization consists in a bed of solid particles acquire fluid behavior by using a fluid (in this case air) flowing through the solid particles. Because of this, it can be a good mix of these materials, as well as to show increased rates of heat and mass transport. The fluid flowing through the spaces between the particles gives an interstitial velocity, that if is too low does not cause movement of the particulates. The gradual increase in speed will generate small vibrations between the particles promotes its fluidization. Our study focus in the fluid state of solid bed , when the fluid velocity reaches a state where the drag forces are sufficient to support the weight of the solid particles making these solids behave like fluids . Knowledge of the minimum velocity required to fluidize that particles is of great importance since below this speed there is no fluidization, and far above it, the solids are carried out of the bed. The fluidized bed reactor is widely used in physics and engineering, particularly in gas-solid fluidization, with emphasis on thermochemical processes

Utilização de reforço geossintético em vias ferroviárias

This report analyses the use of geosynthetics in railways for subgrade reinforcement and separation of the track layers. Cases of instrumented test sections were studied. These test sections were located in Australia (with geocomposite applications), Brazil (with geotextile and geodrid applications) and China (with geotextile and geodrid applications). Railway design methods using geosynthetics applications were analyzed as well. Based on a studied case for implementation of geosynthetics in a German railway, a railway track was simulated with and without the use of geosynthetics, respectively on PLAXIS v.8 and FERROVIA 3.0 softwares. The performance benefits of the geosynthetics applications in railways were, therefore, confirmed, based on the simulation results

Análise microestrutural de tubos API P110, para prospecção de petróleo e gás, soldados pelo processo HF/ERW

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT P110, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of nonmetallic inclusions in the welded joint

Carta geotécnica das sub-bacias dos córregos do sossego e do barracão nos municípios de Americana e Santa Bárbara D'Oeste na escala 1:20.000

The Geotechnical Mapping is an extreme important tool for the urban planning, so the public authorities can establish guidelines for medium and long term for a better life conditions for the population. The division region between the cities of Americana and Santa Bárbara D’Oeste has an intense conurbation problem, which is causing problems of occupation in risks areas on environmental terms. In this context this project has as an objective the elaboration of a Geotechnical Map from the sub- basins of Sossego and Barracão rivers, whicht are located in between the area of the two cities, and presents some of the process causes of the conurbation problem. For this study, the following steps were proposed: bibliographic and topographic maps research for better knowledge from the theme and the area, and also preparing cartographic basis; making of preliminary geotechnical area map with a 1:10.000 scale, gather all the information acquired at the previous step and compartmentation of the area; field step to collect more information and soil for the laboratory analysis, objecting the characterization of the geotechnical unities; lab analysis; final geotechnical map preparation; and final report elaboration. The final product of this study is the Final Geotechnical Map, with a 1:10.000 scale, and the principal objective is to help the urban planning

Estudo da propagação de trinca por fadiga sob carregamento de amplitude variável

For engineering projects that require high reliability levels, is often not enough know only physical and chemical material properties. It’s necessary understand the failure mode of these materials in operation to ensure security level in the project and establish more stringent criteria in the analysis of structural integrity. Due to this need, aircraft industry has been using aluminum alloys in their designs and projects. “Currently more than 70% of aircraft structures are built of high strength aluminum alloys among which stand out 7075-T6 and 2024-T3 alloys, which are considered basics for being used in the new alloys development.” (PASTOUKHOV & VOORWALD, 1995). Some years ago ALCOA develops Al 2524 alloy that has emerged as refinement of Al 2024 (Al, Cu. Mg) alloy, with purpose of improve fracture toughness and fatigue resistance on structural components. The present research addresses testing of fatigue crack propagation under variable amplitude loading for Al 2024 alloy, observing the interaction effects from application of overhead blocks and plastic zone at the crack tip and makes an analysis of fracture surface images

Análise estrutural de Tie-Rod pelo método dos elementos finitos e através de cálculos analíticos

Currently one of the great concerns of the aeronautical industry is in relation to the security and integrity of the aircraft and its equipments / components when under critical flight maneuvers such as during landing / takeoff and emergency maneuvers. The engineers, technicians and scientists are constantly developing new techniques and theories to reduce the design time and testing, ir order to minimize costs. More and more the Finite Element Method is used in the structural analysis of a project as well as theories based on experimental results. This work aimed to estimate the critical load to failure for tensile, compression and buckling of the Tie-Rod, a fixture aircraft widely used on commercial aircrafts. The analysis was performed by finite element method with the assistance of software and by analytical calculations. The results showed that the Finite Element Method provides relative accuracy and convenience in the calculations, indicating critical load values slightly lower than those found analytically for tension and compression. For buckling, the Finite Element Method indicates a critical load very similar to that found analytically following empirical theories, while Euler's theory results in a slightly higher value. The highest risk is to fail by buckling, but the geometric irregularity of Tie-Rod pieces makes difficult the calculations, therefore a practical test must be done before validation of the results

Avaliação das condições de contorno da teoria de Hertz, comparando os resultados analíticos e numéricos a partir de simulações em software de elementos finitos

The objective of this study was to present the comparison between analytical and numerical results trying to identify the differences and behaviors of the variation of the principal stresses and the maximum contact pressure for different model configurations. The analytical equations of the theory of Hertz from the boundary conditions adopted by him were differences are shown. A step-by-step of developing the model indicating the geometric dimensions, surface contact, type of contact, the formulation used by the software, type of mesh, as well as the boundary conditions and load was presented. In the results, the stresses calculated analytically and compared with the stresses obtained by the finite element simulation software indicating the changes have been made

Avaliação da tenacidade à fratura em juntas soldadas circunferenciais de tubulações de processo

This work aims to analyze the toughness of a welded joint in the presence of a crack through the analysis of maximum tension the material can withstand the presence of this type of defect, since a discontinuity is likely to occur in this type of joint and its detection and its design is simple, using non-destructive testing techniques. The study will be conducted through the CTOD test - Crack-Tip Opening Displacement, with type specimens SE (B) - Single Edge Bend taken from a weld in the L-C position in relation to the length (longitudinal axis) of a test tube. The main idea is to simulate the welding conditions for the manufacture of industrial pipes, made in boiler shops (pipe-shop) within petrochemical plants. These pipes are often subject to operation with flammable and toxic subjected to high pressures and temperatures, where one can break the line can cause irreparable damage to the plant, the environment and the health of surrounding communities. With this study we evaluate whether the weld metal has the same properties as fracture toughness of the base material. This study shows the importance of using a qualified welding procedure for performing quality welds while maintaining the properties of the fracture toughness of the base metal. It was found from the results of tests using a welding procedure described for carrying out welding ensures mechanical properties very close to the base metal, which in terms of design is great, since one can ensure that the weld will the same characteristics of the base metal specified for the assembly of the pipe

Uso do modelo de simulação 'ABC 6' para avaliação de áreas sujeitas à ocorrência de ondas de cheia e corridas de massa/detritos: estudo de caso na bacia do Ribeirão da Prata (SP)

Pipelines are linear engineering works, designed mostly for transporting oil and its derivatives for long distances, furnishing even the farthermost zones of the country. Due to oil sector needs to ensure for the safety and conservation of its properties, several geotechnical studies are being held at the pipelines field, in order to preserve this important transportation, and also to prevent accidents, which might seriously compromise the environment and the population who lives around it. The OSBRA pipeline, who connects the city of Paulínia to the capital Brasília, is one of these engineering works that deserves to be pointed out. This research, performed at the Ribeirão da Prata Basin, was a pilot study conducted with the main objective of testing the current methodology efficiency, for future applications in the closest watersheds to the OSBRA pipeline. The objective of this research is to analyze flood wave and debris flow processes in a non-fictional watershed, by comparing two different kinds of methods: the first one based on simulation models (software ‘ABC 6’), and the other one by flood wave and debris flow susceptibility mapping. The results from the hydrological modeling were both hydrographs and ietographs that estimated values of outputs and infiltration. To construct the susceptibility maps were necessary three other maps: ground use and occupation maps, divided according to the different protection degrees that were offered to the ground; maps of dam locations in the area and physiographic compartimentation maps, divided according to the local geology. To complete the methodology, the results were collected from both methods for comparison. The obtained product for this methodology was series of data whose different susceptibility degrees to flood wave and debris flow could define the safest route for a pipeline crossing in this watershed...

Estudo do método Monte Carlo e sua aplicação no modelo SIR

In this work we present a discussion and the results of the simulation of disease spread using the Monte Carlo method. The dissemination model is the SIR model and presents as main characteristic the disease evolution among individuals of the population subdivided into three groups: susceptible (S), infected (I) and recovered (R). The technique used is based on the introduction of transition probabilities S-> I and I->R to do the spread of the disease, they are governed by a Poisson distribution. The simulation of the spread of disease was based on the randomness introduced, taking into account two basic parameters of the model, the power of infection and average time of the disease. Considering appropriate values of these parameters, the results are presented graphically and analysis of these results gives information on a group of individuals react to the changes of these parameters and what are the chances of a disease becoming a pandemic

Estudo dos parâmetros físicos na fluidização em um leito gás sólido

Through measurements of basic parameters for determining the fluidization regime, as particle size, minimum fluidization velocity, bed porosity, etc., This paper analyze the mass distribution of the phases of the bed to be discussed in relation to: the flow gas physical properties of the solid particles and the forces acting on the solid particles circulating within the bed, as the weight force, buoyancy and drag forces (Stokes' Law). Due to the weight force is constant, open up the discussion about which of the other two forces, buoyancy and drag force, influencing the behavior of the bed. We used the photographic method to realize the statistical analyzes. Therefore, we can conclude what changes can be made more convenient in fluidizing the bed to obtain the highest efficiency for a good mixing used in industrial processes

Aplicação do método AHP para hierarquização de condicionantes de corrida de massa

Among the flow, the flows have the highest destructive potential, may cause disasters with a very high number of victims, as recorded in the events Caraguatatuba (SP) and the Serra das Araras (RJ) in 1967; Valeu do Rio Figueira, in Timbé do Sul (SC) between 1995 and 1996; Vale do Itajaí in Santa Catarina, in 2008, Teresópolis, Petrópolis and Nova Friburgo (RJ), in December 2010 and January 2011. This project aimed to prioritize the main determinants of inducing processes of debris flows by applying the method of decision making AHP (Analytical Hierarch Process). Therefore, the following stages of work were defined: research of the major factors of debris flows, questionnaire design method for application of AHP expert on the subject, analysis of the results obtained from calculating the ratio of consistency and preparation of proposal for hierarchical of conditions for debris flows. From the surveys it was possible to establish a relationship of conditions according to the scale of work, defining three levels: regional (1:250,000 to 1:100,000), Semi-Detail (1:50,000 to 1:25,000) and Detail (1: 10,000 or higher). The factors found were: concentration time, the flood wave, rain, landslide susceptibility (slope), drainage and development in the deposition. The project analyzed the results obtained from the questionnaires, which allowed the ranking of the constraints, contributing to weight constraints in studies of multicriteria mapping of susceptibility to the occurrence of debris flows. The study showed that the most of the analyzed datas were inconsistent because of the different opinion of the judges