Rita de Cássia Silva

Estimation of the Geometric Parameters of a Front Double Wishbone Suspension Based on Geometry Formulation

Vehicle suspension stands out as an important subsystem, which allows vertical compliance to the wheels following an uneven road; keeps the proper steer and camber attitudes, resist roll of the chassis and provides comfort for passengers. The suspension subsystem needs to comply with stability, handling and optimum steering based on an appropriate suspension geometry.Nowadays, the use of simulation software in automotive design has increased. However, the cost and complexity of such software can make them unavailable to those working in the domain, especially the young designers working in vehicle’s student competition (Baja SAE®).Thus, this paper aims to propose a methodology for assessing a frontal Double Wishbone suspension, which is based on a set of analytical equations implemented computationally at Matlab®. The formulae are developed considering simple concepts of algebra, trigonometry and geometry.The input data are the Cartesian coordinates (x, y, z) of predefined points, which are obtained from the CAD design and the bound/rebound travel.The main results are the simple analytical formulae, for the most important suspension’s geometric parameters: caster, camber and toe angles.These analytical results are validated with MSC ADAMS®, particularly its add-on specialized for the automotive industry ADAMS/Car®, showing good agreement.Copyright

Integrity Assessment of Pickup Vehicle Occupants in Rollover Situation Considering Internal ROPS Device: A Numerical Approach

The rollover accidents represent a major cause of injuries and death of vehicle occupants and they are also higher among light trucks than passenger cars. The pickup trucks have important applications in mining scenario where protective structures are required to provide safety in case of a rollover during engineering works. The use of safety devices commonly referred to as ROPS-Rollover Protection System in this kind of vehicle has been shown to be an effective manner to mitigate some of the effects caused by this event, ensuring safety and integrity of passengers. Such device can be constructed using steel bars which constitute a framework to be added into the vehicle, like a cage, in order to minimize the structure intrusion in rollover accidents. In this context, this paper makes up the assessing the integrity of pickup truck occupants in rollover events of a priori designed and proposed ROPS. For this a numerical simulation is carried out based on the experimental Roof Crush Test (FMVSS-216 regulation) using the software LS-Dyna® which uses Finite Element Method (FEM). The criteria for neck and head injuries are established in the standard FMVSS-208. The analyses were conducted comparing the vehicle model equipped with and without internal ROPS.

Programação em matlab para a análise de tensões em barragens gravidade de concreto com a consideração de sismos e sedimentos

Having in mind the social and economic importance that dams have in Brazil and the large investments made in relation to these structures, the objective of this work is to contribute to the study of these structures, through developing a program in MATLAB™™ language for stress analysis in concrete gravity dams. The routines developed allow usual verifications in dam projects, considering the action of silts and earthquakes stands out and also the variation of the geometric parameters and physical properties of the dam. The earthquake analysis follows two methods the Pseudo- Static method (Westergaard Method) and the Pseudo-Dynamic method (Chopra Method). Before presenting the subroutines and the program’s functions, these methods are briefly discussed and a validation of stress results are made using CADAM 2000. Additional analyses are presented in reference to program’s potentialities and the conclusions.

Analysis of biomaterial latex-derived flow mechanical controller

This paper describes the basic guidelines for developing an innovative biomedical device. It covers the issues of researching about a suitable material, developing a new device, and testing its proprieties to check its effectiveness. The goal of the device is to control food flow into the esophagus, reducing its volume and the speed of food intake to help in the treatment of obesity. This module, called Esophageal Flow Controller (EFC®), is made of latex. Three different models of prototypes were developed, and 10 units of each model had their constructive and mechanical characteristics evaluated. All of them have followed the same manufacturing cycle. The results showed that the Esophageal Flow Control module has all the essential characteristics of an effective device for flow control in the esophagus.

Estudo da influência da inclinação dos paramentos na estabilidade e tensões em barragens gravidade sob ação de sedimentos

Na analise de tensoes em barragens gravidade de concreto, verifica-se que a configuracao geometrica do perfil tem grande influencia no posicionamento da resultante dos carregamentos atuantes na estrutura. Devido a baixa resistencia a tracao do concreto, e desejavel que estas resultantes se encontrem dentro do Nucleo Central de Inercia (NCI) da secao. Tal condicao e bastante favoravel, pois evita o surgimento de tensoes de tracao, evitando tambem o surgimento de fissuras no concreto e promovendo um aumento da vida util do mesmo. Neste trabalho, por meio do estudo de perfis teoricos, propoe-se uma formulacao analitica geral pela qual se estima(m) o(s) valor(es) do(s) ângulo(s) de inclinacao dos paramentos da barragem a partir do qual nao se identificam tensoes de tracao no perfil. Esses ângulos sao determinados exclusivamente em funcao de parâmetros geometricos do perfil e propriedades dos materiais envolvidos. A estabilidade do perfil e verificada pelo coeficiente de seguranca ao deslizamento (CSD), onde as forcas resistentes ao deslizamento sao comparadas com a resultante das forcas horizontais solicitantes. Por fim, os resultados obtidos com a analise do estado de tensoes e da estabilidade do perfil sao confrontados, o que permite verificar os ângulos minimos de inclinacao do paramento que atendam as condicoes especificadas.