It's the beginning of 2009. I'm sitting in one of the lectures of my Ph.D. program. Finally, we will start to learn about Finite Element Method! My company is slowly developing, and I'm really hopeful that this will allow me to spread my wings! And then professor says: "let's start with basic matrix operations"... You [...]
Interpreting analysis outcomes is not simple. Even if you already have proper values from your FEA analysis, still you need to decide how to interpret FEA results. Let's take a closer look at how to approach this task! Firstly let's wonder how to interpret FEA results? In structural design, you have to perform several checks. Firstly, [...]
This topic was on my mind (and on my to-write list) for a very long time. Finally, I had the time to organize what I want to write about it in my head. I wonder what is your take on this matter - be sure to leave a comment below! What does it mean to [...]
I got a really interesting question on my email from Fateme. I wanted to address this issue so many times now, so finally there is a great occasion to do this! In Abaqus, can we review the capability of a structural member? Whether or not it can bear the load like: shear, bending, twisting, axial [...]
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 [...]
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 [...]
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: [...]
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. […]
Most engineers use a popular approach: connection is either a hinge or a rigid one. This is usually not the case. Just as with many other engineering problems in certain cases we simplify the reality by assuming perfect conditions (i.e. hinge). It is crucial to understand when such assumptions are incorrect, as this may lead [...]
Using deformations from linear buckling as imperfections in nonlinear buckling case is the most common approach. I will use a simple example to prove that this is not always the best idea. Proper selection of imperfections is a very complicated process – I hope to shed some light on this matter. […]
Nonlinear buckling is a really interesting analysis. It gives you enormous possibilities, at only a few minutes worth of work. At the start, it might be frustrating to set it up (there is a learning curve involved), but in the end, it is a default engineering tool for me right now! Possibilities are limitless! [...]
Buckling is a dangerous phenomenon. It can lead to catastrophic failure of a structure, even if stresses are far smaller than yield limit. You can use linear buckling analysis to verify structural stability. In this post, I will discuss positive aspects and limitations of linear buckling. […]
Connection rigidity is important in many structural solutions. However taking it into account requires time, the time we usually don’t have. I share here my views on when connection rigidity is important, and when can it be ignored. […]
Slippage in connections is often neglected in the design of steel structures. I have seen its importance when I was working in the team investigating the structural failure. Just as easily I could learn about it when it was my design under investigation! It is incredible how easy it is to discard slippage from calculations, [...]
This is the third post about the rigidity of the connections in steel structures. Since we already have discussed what a hinge actually is, and how to calculate the connection rigidity, it is time to discuss how this all fits into the static design. It is also important to discuss the impact of connection rigidity [...]
In last post, we have learned how to check if the connection is a real hinge. Today we will treat our joint between steel members as semi-rigid and we will calculate connection rigidity. This is a very useful tool. It can be used to make an even more accurate design if necessary. If you ever [...]
In the first workshop for students in WrUT organized by Enterfea and Dlubal, a problem of rigidity of the connections in steel structures was presented and discussed. I had a pleasure to teach there with Ola Kociołek (CEO of Dlubal Poland). Have you ever wondered how to be sure that your connection is a hinge? [...]
Today I will post about something a little bit different. I had an opportunity to be at International Conference on Metal Structures (ICMS 2016). It was a 3-day event gathering scientists and practitioners from all around the world to discuss new trends and ideas in steel structures. I had a privilege to have 2 presentations [...]
Lateral torsion buckling (LTB) is a very dangerous phenomenon, that can easily cause the collapse of a poorly designed beam. In civil engineering codes, the critical bending moment is crucial in the proper design of bent beams susceptible to LTB, as it allows for slenderness calculation. In “typical” cases everything is ok since code equations [...]