Estudo sobre elementos finitos de placas baseados na teoria de Reissner-Mindlin

Abstract

This final paper presents a study about finite elements based on Reissner-Mindlin plate theory, which is applicable for plates of any thickness. The purpose is to promote a quali-quantitative convergence study that covers configurations with different boundary conditions, loads, geometries, thicknesses and elements. Each one of these models is evaluated in two integration conditions. The first one using only full integration and the second comparing it with the reduced and selective integrations, the shear locking techniques in thin plates. After this study, a qualitative investigation is done considering the previous convergence, their spurious zero energy modes and computing time. The simulations were done using the INSANE (INteractive Structural ANalysis Environment) system. From the results, it was verified the good performance of the techniques to avoid shear locking in thin plates especially when Q4 element is used, and a new way to solve this defect by using full integration with elements of higher order and smaller dimensions. In moderate thickness and thick plates, reduced and selective integrations combining with lower order elements, such as Q4 and Q8, is also an alternative in cases where higher order elements with full integration is not possible. Each one of these distinct possibilities on doing the same analysis have different performance about convergence, spurious modes and time. It is concluded there is no ideal path in analysis of plate finite elements. Although a good balance between the three parameters mentioned before, becomes useful to decide which is the best choice in every single simulation to be executed.