Today, Finite Element Analysis is helpful in almost all industries, especially for mechanical engineering jobs. With the advancement in new software, you can use the FEM (Finite Element Method) from stress analysis to flow analysis. FEA decreases the burden of testing. So, it can be a useful tool for assisting Mechanical Engineers to design and manufacture new products.
Finite Element Analysis is a comprehensive method incorporating boundary conditions, mesh, and contacts. When engineers first used computers for FEA analysis, they used massive computers to solve the problem. Today even desktop computers generate FEA results exceptionally quickly.
An FEA study is complex and only valuable if it produces accurate results, which can lead to better decision-making. Even if your results are spot-on, they will only be helpful if evaluated correctly.
Our machinery and products will need to improve in quality, weight, strength, durability, and price to remain competitive. Consistent innovation necessitates fresh approaches; similarly, there is always a supply of novel architectural concepts. FEA is ideal for engineers, but only if applied and evaluated correctly.
Back to Basics in Finite Element Analysis
One of the main goals of engineering is to figure out what will happen to a physical system when its environment affects it. The method may exhibit certain behaviours if subjected to the circumstances above. The design of interest could be a building, an airplane, or a piece of mining equipment.
The main goal of an analysis is to try to predict how the system will act. Finite element analysis (FEA) is a way to model a physical system with math. The math model is based on differential equations in most critical physical problems. The finite element technique divides each physical geometric domain into smaller units known as finite elements (meshes) to approximate the differentiation procedure.
The FEA software widely used today is based on the same idea. Since NASA helped make the first commercial FEA software, NASTRAN, many new programs have been made. These programs cut down on the time it took to design machines, buildings, and many other systems in all engineering areas, significantly affecting businesses.
Static structural stress analysis is one of the most common types of FEA analysis. The main goal of stress analysis is to look at the stress levels on machine parts to ensure they meet standards and keep working throughout their service lives.
Some of the other types of FEA analysis are as follows:
- Static Structural
- Vibration
- Crack and Fracture
- Fatigue
- Thermal
- CFD (Air Flow Analysis)
- Explicit (e.g. Crush)
- Fluid Dynamics
Post-Processing of FEA Analysis
The general procedure of finite analysis can be mainly split into three stages:
- Preprocessing
- Processing
- Post Processing
Preprocessing is the step where data used in finite element analysis are prepared. The shape, the contacts, and the boundary conditions are all set. At this point, the mesh of the finite elements is also made. During the processing stage, the computer works out the equations and tries to get the results to converge.
On the other hand, post-processing is the last step of the analysis. During the post-processing stage, the results are shown graphically. If the user did everything right in the preprocessing stage and the model is a good representation of the physical world, a lot can be learned from the data shown.
At this point, the data are interpreted. A static structural analysis includes the following:
- Displacement gradients
- Stress gradients
- Nodal forces
- Contact status
Later, these results can be fed into other types of analysis, such as vibration or crack analysis. The job of the engineer and a designer is to make sense of data that has already been processed.
For example, the displacements tell us how the geometry of the component changes. The equivalent stress lets you figure out how long the part will last mechanically. The engineer will then decide if the part will fail under those conditions. For example, a component might look fine when stressed but fail because of fatigue.
Interpreting FEA Results and Mechanical Engineering Experience
Even though FEA analysis has become much more common, many people need to remember that it is a tool that requires an engineering background. If you don’t know how to understand the post-processed data, the FEA analysis doesn’t help you.
More and more attention is being paid to meshing the models. Of course, you need a good mesh to get good results. But you need a good model and engineering experience to know what the results mean. Colourful pictures of the results mean nothing if you don’t know what they imply.
A mechanical engineer uses the results of the FEA to see if the part meets the requirements. First of all, a component must withstand the effects of the environment. Depending on the environment and how the machine works, a part can fail in many ways. Some ways that a component can break down are:
- Tensile-yield-strength failure
- Bending failure
- Stress concentration failure
- Creep/rupture failure
- Fatigue failure
- Corrosion failure
A mechanical engineer with a lot of experience can figure out what a part needs in its design. When you use FEA analysis and post-processed data, you can look at a component’s stress levels, mode frequencies, and deformations. Using engineering methods, such data can be used to see if a part meets the requirements. Life, weight, etc., are all examples of such needs. Also, engineers can use this kind of data in a loop to improve designs or solve problems.
A well-planned effort helps by choosing a design that is likely to work well and keep it safe. By analyzing the failure modes, engineers can also find out how the failure modes affect the whole system and use this information to plan tests early on.
But for all these things to work, you must know what you’re doing. Design requirements vary from industry to industry. To understand the design requirements and evaluate FEA results based on what the industry needs, you need a solid background in engineering in those areas. For example, a mechanical engineer working in the mining industry won’t worry about how heavy a part is but how much force is being put on it.
Conclusions
When parts of machines break, it can seriously affect safety, money, the environment, and compliance. It is essential to understand how machinery and its components work fully.
FEA analysis is an excellent tool that engineers use on many systems. But you need a lot of engineering knowledge and experience to understand the results and use them in a planned way.
Aerospace, agriculture, mining, automotive, rolling stock, and manufacturing have different equipment standards and requirements. To use FEA analysis on these pieces of machinery, you will need to know everything there is to know about the industry and have the right qualifications.
At Trevilla Engineers, our experienced Structural and Mechanical Engineers have experience with Finite Element Analysis and post-processing. Get in touch to discuss your engineering design and testing requirements.
