This paper on "A New Primal-Mixed 3D Finite Element in Analysis of Plates and Shells" was presented at the NAFEMS World Congress on The Evolution of Product Simulation From Established Methods to Virtual Testing & Prototyping - 24-28 April 2001, The Grand Hotel, Lake Como, Italy.

Summary

In the present paper a new primal-mixed finite element scheme, able to cope with unmodified, completely 3-dimensional constitutive laws is investigated. One of the basic motivations for the development of such method is the increasing importance of reliable material formulation. In addition, the objective was to attain numerical efficiency, including the fully 3-dimensional continuous displacement and stress fields. The performance of a new low order three-dimensional HC8/9 finite element in the coordinate independent primal-mixed formulation is investigated. The main goal is to show that this element can be reliably used in the case of regular compressible and nearly incompressible plates and shells model problems.
The reliability and efficiency of computational mechanics method are in the very focus of the research interest nowadays. The reliability in computational mechanics is a property of the utmost importance and it can be observed in two different stages. Firstly, in the stage of designing, reliable finite element method is one that is solvable, accurate, stable and robust [1]. Secondly, in the stage of exploitation, reliability of the system can be defined as the probability that the structure will adequately perform its intended mission for a specified interval of time when operating under specified environmental conditions [2]. On the other hand, efficiency represents the ability to obtain the accuracy of a prescribed level in a reasonable time and it is an important property particularly from the end users point of view.