Finite element analysis (FEA) is a powerful tool for structural engineering, but it can also be complex and time-consuming. To get the most out of your FEA, you need to organize your workflow and data in a clear and consistent way. Here are some tips on how to do that.
Before you start your FEA, you should have a clear idea of what you want to achieve and how you will measure it. What are the main questions you want to answer? What are the key parameters and criteria you want to evaluate? What are the assumptions and limitations you need to consider? By defining your objectives, you can focus your FEA on the most relevant aspects and avoid unnecessary complications.
A key objective to define is the design criteria. The design criteria should clearly state the governing design codes. Next, the individual load cases can be defined and developed. Load cases can include; dead load, live load, wind load, ice loads, and seismic loads. Once the load cases have been developed, the load combinations can be defined. Load combinations consider which load cases occur simultaneously.
The next step is to choose the type and size of your model. Depending on your objectives, you may need a 2D or 3D model, a linear or nonlinear analysis, a static or dynamic loading, and so on. You should also consider the level of detail and accuracy you need, and how to simplify or idealize your model to reduce the computational cost and time. For example, you may use symmetry, submodels, or boundary conditions to reduce the size of your model.
This step is crucial for the analysis process. The more you can simplify the geometric model the faster you will be able to solve it. This will save you time to run more analyses and be able to better understand how the structure behaves. It is tricky though as simplifications should be based in your engineering judgement so you have to make sure the model you are using is actually behaving like the real structure. Once your simplified model is up and running and you know its response to the loads exerted, then you can work on a more detailed model: more complicated geometries (using submodelling techniques), more advanced analysis (like nonlinear analysis) and so on. It will all depend on the objectives your project has.
Once you have your model, you need to set up your elements and mesh. Elements are the building blocks of your FEA, and they define the shape, material, and properties of your model. You should choose the appropriate element type and size for your model, and check the quality and compatibility of your mesh. You should also verify that your elements are correctly connected and oriented, and that they can handle the loading and boundary conditions you apply.
After you have your elements and mesh, you can run your analysis and solve your model. You should check the convergence and stability of your solution, and make sure that there are no errors or warnings in your output. You should also compare your results with your expectations and assumptions, and validate them with experimental data or analytical solutions if possible. If you find any discrepancies or problems, you may need to revise your model or parameters and run your analysis again.
The final step is to interpret your results and draw conclusions from your FEA. You should use appropriate visualization tools and techniques to display and explore your results, such as contour plots, graphs, animations, or tables. You should also perform post-processing operations, such as stress or strain calculations, factor of safety checks, or sensitivity analyses, to extract more information from your results. You should be able to answer your initial questions and objectives, and explain the implications and limitations of your results.
A simple way to verify your input loads is to check the reactions of your load cases. Does the total reaction of your dead load equal the weight of the object you are designing? If it does not, there is an error is the assigned loads.
A good FEA is not complete without a proper documentation of your process and findings. You should keep a record of your model, parameters, assumptions, methods, results, and conclusions, and organize them in a clear and logical way. You should also use consistent and descriptive names, labels, units, and formats for your data and files, and follow the standards and conventions of your field. By documenting your FEA, you can ensure its reliability, reproducibility, and communication.