Candidate: Rodrigo Szpak
Program: UFSC / POSMEC
Date: November, 2008
Advisor: Victor Juliano De Negri
Abstract: This research deals of the theoretical and experimental study of the dynamic behavior of the cylinder chambers pressures in loaded hydraulic position systems, focusing on helping in the choice of the combination of symmetric and asymmetric valves with symmetric and asymmetric cylinders. This study is based on the behavioral analysis of the critical pressure conditions in the cylinder chambers, with different loads, analyzing the occurrence of critical points that can cause damages to the system. The results obtained can lead to the identification of the static and dynamic characteristics required for the hydraulic positioner components in several configurations. The study was conducted using computational tools of dynamic analysis and experimental validation through the equipment Proportional Hydraulic Plataform (PHP). It was used the apparent mass effect caused by acceleration of fluid through ducts of little diameter to reach a higher inertial effect in the system, needed during the experiments. The computational simulations generated in Matlab/Simulink were experimentally validated and were used to study limit situations with loads over the equipment capacity. Finally, this study allowed a better understanding of the effects of cavitation in some configurations of valves and cylinders with different loads, supporting the choice of the most adequate alternative for the electro-hydraulic position systems design.
SZPAK, R. Análise Teórico-Experimental do comportmaneto das pressões em posicionadores hidráulicos. 2008. Dissertação (Mestrado em Engenharia Mecânica). Universidade Federal de Santa Catarina, Florianópolis. 143 p.