Why the term “Finite”?

Because the study is limited to a closed system under a predefined set of conditions. Any other interactions outside the system are ignored. That is why every FE Analysis first requires the understanding of ‘Purpose’ so that we can properly define the relevant parameters.

For example, if we are interested to simulate the Stresses at a cylinder to nozzle junction due to external loads, we need to know the Dimensions, Pressure, Thickness, Material, etc. but we may not be worried about Flow velocity of the fluid, or a dished end far away from the junction.

Why the term “Element”?

Each closed system under consideration is divided into smaller shapes (elements), the properties and behavior of which are mathematically defined. For Example, an irregular
shape can be divided into small elements of Triangular shapes as shown in next slide.

Notice that element size is larger in regular area and around the large circle, but very small around the smaller circle and corners. In FEA terms, this method of dividing the object into small elements is called Meshing (we will discuss about it later).

FEA:

Thus, in simple terms, FEA means Analysing a closed system under predefined parameters by use of smaller elements that can be solved mathematically.