Application

FEA with a computer analysis provides a means to theoretically predict the structural integrity of a product using mathematical geometry and load simulation. A stress analysis can be taken of finite sections for analysis of the forces and loads the part will experience in service. It generates an analysis that shows the force concentrations in the section and determines if the material and design shape selected will meet product performance requirements.

In reviewing mechanical engineering analysis, one can perform using one or two approaches, namely analytical or experimental. Using the analytical method, the design is subjected to simulated conditions, using any number of analytical formulae. By contrast, the experimental approach to analysis, requires that a prototype be constructed and subsequendy subjected to various experiments, to yield data that might not be available through purely analytical methods.

There are various analytical methods available to the designer using a CAD system. FEA and static and dynamic analysis are all commonly performed analytical methods available in CAD. FEA is a computer numerical analysis program used to solve the complex problems in many engineering and scientific fields, such as structural analysis (stress, deflection, vibration), thermal analysis (steady state and transient), and fluid dynamics analysis (laminar and turbulent flow).

The FEA method divides a given physical or mathematical model into smaller and simpler elements, performs analysis on each individual element, using the required mathematics. It then assembles the individual solutions of the elements to reach a solution for the model. FEA software programs usually consist of three parts: the preprocessor, the solver, and the postprocessor.

The program inputs are prepared in the preprocessor. Model geometry can be defined or imported from CAD software. Meshes are generated on a surface or solid model to form the elements, Element properties and material descriptions can be assigned to the model. Finally, the boundary conditions and loads are applied to the elements and their nodes. Certain checks must be completed before the analysis calculation. These include checking for duplication of nodes and elements and verifying the element connectivity of the surface elements so that the surface normals are all in the same direction.

To optimize disk space and running time, the nodes and elements should usually be renumbered and sequenced. Many analysis options are available in the analysis solver to execute the model. The FEA stiffness matrices can be formulated and solved to form a stiffness value for the model solution. The postprocessor then interprets the results of the analysis data in an orderly manner. The postprocessor in most FEA applications offers graphical output and animation displays. Vendors of CAD software developing pre- and post processors that allow the user to visualize their input and output graphically.

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