If you are a Mechanical Engineer or starting your career as a Mechanical Engineer or as a Structural Analysis Engineer. It is essential that you have a good understanding of Finite element method and its role in structural Integrity assessment.
Mechanical Engineers in the CAE Domain use stress or structural analysis to asses the mechanical components strength to withstand the loads they are subjected as they go on to perform their intended functionality. But how do we verify if they withstand these loads.
We apply the loads and we will check things like stresses and deformations. We verify if these stresses and deformations are within the limits or not. These stresses and deformations are one of the verify fundamental ways of checking a structure’s structural Integrity.
Now when we say we will check for this stresses and deformations, what exactly do we mean. For a mechanical component, where do we check for stresses that it ensures the component is safe under loads.
Theoretically a component can fail anywhere in the body or at any point in the body. Mechanical components especially metallic components are 3D solids. These solids are dense continuous materials. So in this continuous material which points should we check for stresses. A continuous material will have infinite number of points where the body can fail. So ideally if we want to check for structural integrity, we should be checking for stresses at infinite number of points, which is totally impractical.
Its like asking every person in the city which is a good restaurant or which is a good place for outing. Think about any other better approach. We don’t need to ask every person in the city to find out these things. Instead the best way to find out these things without troubling ourselves or the others is to ask a handful of people at strategic locations so that we get the right idea about the restaurants or places.
In stress analysis we do something similar. We don’t check for stresses at every single point in the body.We decide upon a limited number of points at strategic locations and check for stresses at these points. So we saw that there are infinite number of points in a body and now we see that, we can check stresses at finite number of points. So we have moved from an infinite domain to a finite domain. We breakdown the initial Infinite domain to a finite domain. These finite domains are the finite elements, that’s where the name finite element comes from. These finite elements are connected at the finite points we spoke before. These points are called the Nodes in the FE parlance. These nodes and elements combine creating a sort of stress-measuring grid.
Now we don’t need to worry about checking every nook and corner of the body for the stresses. So the finite element saves the day for the Mechanical engineers by crunching the numbers at these strategic nodes and use those insights to understand the entire picture of what’s going inside a mechanical component.
The Finite One 