## Process of nonlinear design on example of polygonal shell column

I have recently calculated a polygonal column for a book my friend writes. I have decided to use this real-life example to show how the process of numerical design looks like in practice. […]

Process of nonlinear design on example of polygonal shell column

## How to set up materially nonlinear analysis

In this post I will show you how to define and run a materially nonlinear analysis in a video tutorial. This is the type of analysis that will allow you to calculate a plastic collapse load of the model. This is one of the important parameters in numerical design. […]

How to set up materially nonlinear analysis

## How to set up geometrically nonlinear analysis

Have you ever performed an analysis that did not converge, or that ended with the result you did not expect? Many of such problems are resolved with correct solver settings, and today I will discuss how to set an arc-lenght geometrically nonlinear analysis of a shell. This means we will do a nonlinear buckling problem [...]

How to set up geometrically nonlinear analysis

## Nonlinear analysis setup – Steering

As I wrote previously in many cases nonlinear analysis of buckling yield better results than linear buckling. Setting up an analysis like that however requires certain knowledge. Today I will discuss steering of numerical analysis that is crucial in proper task definition. […]

Nonlinear analysis setup – Steering

## Linear vs Nonlinear Buckling

Topic of linear and nonlinear buckling is one of the most searched FEA topics. It is understandable, since lack of knowledge about the difference in both approaches can lead to great overestimation of model capacity and following real-life instability failure. In this post I will discuss the difference with a shell example. […]

Linear vs Nonlinear Buckling

## How to choose correct mesh size

In this part of shell design course we will use Linear Bifurcation Analysis (LBA) to estimate shell capacity. The main part of this post however is about choosing correct size of mesh and present a way to estimate at which mesh size accuracy of solution is acceptable in performed analysis. […]

How to choose correct mesh size

## Full guide on how to model shell in FEA

This is a start of a design course I will publish on my blog. The aim is to show you the basics of design in FEA with some shell specific issues. Several side-topics as: mesh density or linear vs nonlinear buckling will also be discussed. I will make recordings of my preparations of models in [...]

Full guide on how to model shell in FEA

## LBA: Linear Bifurcation Analysis (Linear Buckilng)

Sometimes you just want to have a quick and rough estimate of model buckling capacity. Linear Bifurcation Analysis (also called “Buckling” in many software packages) does exactly this! In the analysis solver gives you the minimal multiplier (sometimes denoted as α, or called eigenvalue) such that when you multiply the applied loads with this multiplier [...]

LBA: Linear Bifurcation Analysis (Linear Buckilng)

## Side-project: When shell model is not enough

I had some interesting experiences with my current side-project. I have decided to use shell model as usual, but since in my laboratory test rings and stringers were quite small (so their rigidity was in scale with the model) I have decided to model them as solids. Somewhere along the [...]

Side-project: When shell model is not enough

## Issues in result interpretation of nonlinear analysis

I think that one of the most difficult things about FEA (or really any other form of analysis) is interpretation of results. Unfortunately in my engineering work I have found many examples where people completely misunderstood what is the outcome of the analysis they have performed. […]

Issues in result interpretation of nonlinear analysis

## Introduction to material and geometric nonlinearity

Want to learn about nonlinear FEA? You are in the right place! Since publishing this post I wrote several others, that might interest you: How does nonlinear geometry really work on real life example! What does nonlinear material do, and how! The difference between linear and nonlinear FEA If you have any questions about FEA, [...]

Introduction to material and geometric nonlinearity