Do you need to know math behind FEA?

By |November 30th, 2017|FEA: Basics, • Linear Analysis, • Nonlinear Analysis, FEA: Intermediate, FEA Topics:, Art of Engineering|

Recently I asked a lot of my subscribers what they think is the most difficult thing in FEA. While "interpreting results" or "too much theory in materials" appeared quite often, I also got several answers like: My biggest obstacle is actually understanding the mathematical concept behind it. Although I am really interested in the application [...]

FEA results verification with hand calculations: stability

By |October 19th, 2017|FEA: Basics, FEA: Intermediate, • Post Processing, FEA Topics:|

Last time I described 5 steps to FEA results verification. Among those steps were FEA results verification with hand calculations. I figured it makes sense to expand on this idea. Especially since Luke asked me about something on this topic via email. Luke asks: How is the eigenvalue calculated, can this be done longhand? Can [...]

Nonlinear supports in FEA: Gap Elements (NX Nastran) [Q&A #2]

By |September 12th, 2017|FEA: Intermediate, • Boundary Conditions, • Contact, FEA Topics:, Q&A, FEMAP|

Recently I got a great question from Ardalan (thanks for writing mate!) about defining nonlinear supports in FEA. I think he does a better job of defining the problem: First how to constraint an entity with in tolerance rather than completely fixing it? i.e. how to define a certain range of motion for an entity [...]

Buckling length in sway and non-sway structures

By |August 31st, 2017|• Structural Steel, • Stability, FEA: Intermediate, FEA Topics:, • Linear Buckling, Structural Design Topics:|

One of the few difficult things about buckling lengths is, that you need to know if your structure is a "sway" structure or a "non-sway" structure. Commonly the simple check is made with displacements, but unfortunately, it may lead to serious mistakes! Why should you care about sway and non-sway system Firstly, I want to [...]

Changing active forces for enforced deformations and vice versa

By |May 23rd, 2017|FEA: Basics, FEA: Intermediate, • Boundary Conditions, FEA Topics:|

I have seen many mistakes where people wrongly changed enforced deformations with active forces. In some cases, this is a simple task, which gives beginners the feeling that they can always do it easily. This, in turn, leads to various mistakes in analysis. I think it is worth discussing this, to point out common mistakes [...]

Solve issues with nonlinear analysis convergence!

By |May 16th, 2017|• Nonlinear Analysis, FEA: Intermediate, FEA: Advanced, FEA Topics:|

Lately, I got several emails with questions about nonlinear analysis convergence. There are a lot of reasons why your analysis could not converge. One of them is a wrong loads/increment strategy which I call "steering". Take a look at what are the possible options and what are the positive/negative aspects of each approach. Steering have [...]

Boundary conditions influence on static design – case study

By |March 20th, 2017|FEA: Intermediate, • Boundary Conditions, FEA Topics:, Case Studies, FEMAP|

Each day we do simplifications to boundary conditions just to reduce time spent on analysis. We are all aware, that structured support is crucial, but the actual influence of the proper boundary conditions is rarely examined. See yourself how drastic influence BC have on your design! I will discuss this using a project I just [...]

Design your silos with FEA – it pays!

By |February 28th, 2017|• Structural Steel, • Nonlinear Analysis, • Stability, FEA: Intermediate, • Post Processing, FEA Topics:, Case Studies, Structural Design Topics:, FEMAP|

Designing steel silos with analytical approach always yields very conservative results. Nonlinear Finite Element Method allow for great optimization of those structures (and other shell structures as well!). I will discuss this based on a silo I have recently designed. […]