New Finite Element for modeling connections in 2D small frames - Static Analysis
Abstract
The paper presents a proposal to create a new one-dimensional (1-D) finite element that can substitute for the three-dimensional (3-D) finite model of connection elements in static analysis. The study is conducted on a simple small frame. First, a 3-D model is constructed, followed by the construction of an equivalent two-dimensional (2-D) one. At the final stage, the results of the static analysis of many proposed 1-D element models are compared with the results of the 2-D model. With a special treatment of the connection elements, the results of the analysis of the new 1-D finite element models agree well with the results of the 2-D model.
Keywords
Download Options
Introduction
To perform a static analysis of a frame, 3-D finite elements are usually used in the meshing process. A large number of elements are required, which in turn requires a large number of DOF and consequently, a great deal of work. The main objective consists of developing a 1-D model made up of simple 1-D elements to replace the 3-D model made up of tetrahedral prisms or brick elements. To perform a static analysis, the calculation of the stiffness matrix is required.
In order to find the best 1-D finite meshing element, 3-D meshing is used, and 2-D and 1-D models are consecutively constructed.
All calculations are done by using ANSYS Version 16.2 and MATLAB Version 7. A simple frame is used in the calculations.
Conclusion
Replacing the volumetric modeling of a simple frame by traditional 1-D elements leads to a weak simulation in static analysis. It is found out that the problem arises from corner connections. Modeling these connections by rigid links produces a stiff structure. Using CQ elements at the corners improves the results in the static analysis. Consequently, the number of elements and the number of DOF of the finite element model are dramatically reduced from hundreds of thousands to merely hundreds.