How to Perform a Finite Element Analysis


Finite Element Meshing          A finite element analysis or FEA for short is a way to use computer software and the power of modern computer processing to simulate how an engineering design will perform under certain conditions before it is actually built. Finite element analyses can come in the form of structural analyses, thermal analyses, modal analyses, and others. A finite element analysis uses a physics engine to solve loading conditions as if they were occurring to your material in the real world. Results of a finite element analysis include such data as stresses, strains, temperatures, and deformations. This data can be used as a guide in redesigning a product for increased strength and rigidity or to handle a higher temperature without failing. Follow the steps below to get you started in running a finite element analysis.

Step 1

Create your model geometry based on the design you want to test. Be as accurate as possible in reproducing every detail of your model to true form as even minor discrepancies in a corner’s radius for example can have profound effects on the results of stress and strain in a design. Choose one unit based system such as English or metric and stick with it. You will need to use the same units in both your 3D Cad program as with your finite element analysis software so choose something you are more familiar with.

Step 2

Export your model from your 3D modeling program into your finite element analysis software. Find out what solid import file type your program is most efficient at dealing with and use that one. This will minimize complications with your analysis. For example you might want to stay away from exporting your solid as an .Iges extension then trying to re-glue the pieces together to form a solid in the FEA program. This extra step can lead to issues such as all the pieces not connecting which will completely ruin your finite element analysis results.

Step 3

Once in your FEA program, start a new analysis. Choose the type of analysis you want such as structural, thermal, or vibration.

Step 4

Loads and ConstraintsApply material conditions to your model. Choose the type of material or materials your model is made of by selecting the part of the model first then adding material properties to it. Many FEA programs these days have material databases attached to them so you do not always have to manually input Poisson’s ratios, yield strengths, and Moduli of elasticity for example.

Step 5

Apply loads and constraints to your design. Apply proper constraints to your model such as simulating fixed conditions at attachments at a wall or other part. A fixed condition will prevent a part of your model from moving in either the X, Y, or Z axes as well as rotating about any axis. You can apply any type of restraint you want according to what your finite element analysis software has to offer. Just make sure that your constraints accurately reflect the conditions your design will see in the real world.

Step 6

Load your model. Apply all the structural, vibration, or thermal loads that your model is to be tested against. Structural loads include moments of inertia, masses, forces, and pressures. Thermal loads include temperatures and heat generation. Inertial loads include the forces of gravity.

Step 7

Apply mesh to your FEA model. Meshing your model consists of choosing a type of mesh, picking the density of the mesh, and refining the elements to get good results. Once you have chosen the type of mesh to use, tetrahedral, quadrilateral, hexahedral, for example then mesh the model. If the model is not dense enough such that the elements are not accurately representing the shape of the model down to a low enough threshold then you must re-mesh the model and make it denser.

Step 8

Run your finite element analysis. The FEA program solver will now go through thousands, if not millions of calculations to determine how your model will stress under the circumstances you have provided.

Step 9

FEA results post processingOnce your analysis is complete, load the results into your finite element analysis software’s post processing tool. Once there you can view your model’s stresses, strains, deformations, and temperature results.

How to Mesh an FEA Model   How to Mesh an FEA Model                                                                           How to Post Process FEA Results    How to Post Process FEA Results