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

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

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 [...]

## [Q&A #1] Career in nonlinear FEA and stability of a complex structure

Since I announced Q&A column on my blog I got several great questions so far. I will try to answer as many of them as possible at the end of each month. If you have sent me a question and you didn't find an answer here no worries! I store all of them and I [...]

## This “season” on Enterfea 🙂

Hey! Since summer ended, and I'm back on track I think it is reasonable to call this a new "season". I took a year off from my University (we have a great Dean and he agreed 🙂 ), so I will have some more time for my blog. I admit that most of the time [...]

## Buckling length basics

I'm preparing materials for another training about stability and I figured I have never written anything about frame stability on the blog! It's high time, so I decided to make a small roundup of methods on calculating buckling length in a frame system. Buckling length - do I need it? Let's start with the obvious: [...]

## Symmetry in FEA may be dangerous

Symmetry in FEA is great, as it reduces the size of the task. This, in turn, shortens the computing time. Computing time is still a big issue, especially when you run complex models. Without a doubt, this is why using symmetry in FEA is so popular. There is a catch to this, however, as you [...]

## Is simplistic software killing engineering?

I'm sure that you know just as well as I do, that engineering software is getting easier and easier to use each year. This is great, but I'm afraid that it might come at an unexpected price. I will try to explain what I mean, using fruits and space ships! Apple, apple, banana I remember [...]

## Enterfea on holidays!

I'm on holidays! This means I'm not as active as I usually am, but also that I'm gathering strength for new things to come 🙂 Everything will be back on track in 3 weeks. So stay tuned! If you can't wait and want to read something interesting from my resources, why don't you start here? [...]

## When to ignore geometric nonlinearity?

Linear FEA calculations are the most common type of static analysis done with finite elements. Last week we have discussed when it is safe to ignore material nonlinearity to use this simple yet robust tool. Today I will describe when we can safely ignore material nonlinearity. A short remainder There are several things you should [...]

## When to ignore material nonlinearity?

Linear FEA calculations are the most common type of static analysis done with finite elements. There are a lot of benefits to the method itself, but of course, there are risks involved as well. Today you will learn when it is safe to ignore material nonlinearity. I will also tell you what things you should [...]

## Load multiplier an ultimate FEA outcome

If you are starting with nonlinear FEA you most likely heard the term load multiplier. Usually, people associate this with some sort of "safety factor" but frankly this has nothing to do with safety. In fact, this is the only way you can get an outcome out of nonlinear analysis and today I will explain [...]

## Changing active forces for enforced deformations and vice versa

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!

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 [...]