## General Mechanical

Topics relate to Mechanical Enterprise, Motion, Additive Print and more

#### Questions about the general procedure of FEA

• helen.durand
Subscriber

Hello!

My understanding is the general procedure of FEA works something like this (at least for some types of problems): the equations in FEA are written in terms of the displacements (something like Ku=F, where K is the global stiffness matrix created though summing many local element stiffness matrices, and F is a nodal forces vector), and the displacements are first solved for.  Then the strain matrix (sometimes called the B matrix) is used to calculate strains from the displacement results, and matrix representing the relationship between stress and strain (called the D matrix in the theory reference) is used to calculate the stresses from the strains.

Does this seem like a correct high-level assessment of the FEA procedure?

Does the overall procedure change for transient or nonlinear analyses?

Thank you!

• Ankush Choudhary
Subscriber

Hi Helen,

Your understanding of FEA is correct. In the case of transients, we need to use time discretization techniques like Newmark algorithms. In the case of non-linear systems, we need to use an iterative solver like Newton-Raphson.

There are plenty of courses available on ANSYS Innovation Space related to these topics. These two courses below will help you understand the transient and non-linear solutions.

https://courses.ansys.com/index.php/courses/fea-linear-elastodynamics/

https://courses.ansys.com/index.php/courses/computational-resource-considerations-recommended/