Design sophistication in the area of mechanical engineering and construction is ever increasing.
Therefore, in order to assure reliability, the calculations relating to these designs must be performed using more advanced tools.
To determine the stability and durability of a given structure under various loading situations, observe the stress and deformation in the components while they are being loaded. A structure is considered to be durable if the maximum occurring stress is less than what the material permits.
Various computational methods have been developed for calculating deformation and stress conditions. One of these methods is called the Finite Element Analysis.
The knowledge gained from this stress rating can lead to changing the structure in certain areas, which in turn necessitates changes to the design.
The Finite Element Analysis (FEA) function is a powerful procedure for obtaining numerical solutions to stability problems in all kinds of malleable and elastic areas.
FEA subdivides the area into triangles and then approximates the solution using numerical polynomial interpolation. The finite element method outputs approximate solutions. It is useful in that you can quickly determine the stress and deformation distribution in a plane for plates with a given thickness or in a cross section with individual forces and stretching loads, having fixed or movable supports. You can create base mesh, Isolines and Isoareas, main stress lines and deformed mesh. All results can be inserted in the drawing as diagrams with value tables.
The FEA routine uses its own layer group for input and output. Also it uses a node network with the option to number the nodes and to export the node numbers/results in an output file.
Notes:
- The FEA tool is basic; it is not intended for full FEA analysis. For example, this FEA tool does not consider dynamic loads or temperature influences on materials. The FEA tool is intended to provide an engineer who is familiar with FEA with a general idea where the areas of strength and weakness reside. However, for a complete and final analysis, you should use a full FEA package.
- The FEA tool does not generate a composite Center of Gravity for multiple parts, because it is a tool for single parts only.
- The FEA tool creates a mesh for the enclosed contour. This routine uses a triangle element type with six nodes (linear-strain triangle). When there are short lines near the border (for example, force or supports close to a polyline corner), the routine refines the output around the midpoint, up to eight times (Boundaries => areas => volume). For more information on the algorithms used, see the following documentation:
- Larry J. Segerlind: Applied Finite Element Analysis - 1976, Seite 232 - 239
- Robert D. Cook: Concept and Applications of Finite Element Analysis - 1974, Seite 81 - 84 (the used calculation method)
- H. Rutishauser: Algorithmus 1: Lineares Gleichungssystem mit symetrischer positiv-definierter Bandmatrix nach Cholesky (Archives for electronic Computing, Vol.1 Iss.1 - 1966, Seite 77 - 78)
- J.T. Oden and E.A. Ripperger: Mechanics of Elastic Structures - 1981, Page 10 - 17
- R.J Collins Bandwith reduction by automatic renumbering, IJNME Vol. 6, 345-356 (1973)