Structural Madness

Why does a beam bend? Have you ever asked this question to yourself? Did you get any answer? I know that it's difficult to find an answer about this phenomena. But let me try to explain this to you.  Consider a free falling I section from the top of a building. If it falls freely what do you think will happen? It will remain straight because all the particles are moving at the the same velocity at a particular instant of time and the acceleration is equal to the gravitational acceleration. Here I am considering the case of vacuum or else air resistance will induce some external forces. But now consider that the beam is supported at two ends. What will happen? The thing is, the particles which do not have direct support experience the gravitational force and they will try to move down. But the particles who have direct support beneath them, they will not move, they are reluctant. This thing causes internal forces and the two supported ends because of the strength of ...

Charlie Chaplin, one of the most famous character in the history and you will always find him with his stick. But wait, have you ever seen his stick when he rests on it? The stick in the picture above describes one of the most fundamental characteristic of a column in the field of structural engineering, called "Buckling of Column". But why did it buckle? What made the stick to bend instead of taking the load straight down the ground? Well, here we are to discuss about the event. Buckling is called an instability occurred in a structure because of excessive loading. In 1757, mathematician Leonhard Euler derived a formula for calculating the maximum load carried by a slender column. But what do we mean by slender? When the longitudinal dimensions of the member are much greater than the cross section of the member then it is called a slender member and remember you should use the word slender while describing the compression in column not when there is any tension...

No, this is not a philosophical article referencing the vicious circle of cause and consequence. I just used a catchy title to draw your attention. So what I really wish to answer is what is more fundamental: Stress or Strain? Now, a few of you might argue as to why this question and tell that stress-strain always co-exist. To answer that, I must tell you that it is by looking back that we have a clear vision of the future. Thus differentiating the primary from the auxiliary, felicitates us in making groundbreaking discoveries. And besides, it’s always good to know how the human brain works and what is more instinctive to the homo sapiens. Alright, so let’s get the mess sorted. Probably many of us believe that stress has to be fundamental. We apply a force on a body, it develops stresses and leads to deformations/strains. But, this approach has a basic flaw. How do you measure stresses? All the instruments we presently have all measure deflections and it is by calibrating t...

Progressive Collapse When the collapse commences with the failure of one or a few structural components and progresses over the successive other components then it is known as progressive collapse. This can be the simplest possible definition of progressive collapse. But when a progressive collapse can possibly come into the picture? Well, it can be anything ranging from a damaged column, or a damaged connection, or a blast inside the building, a blast outside a building, a vehicle crashing into the building, aftershocks of an earthquake, a storm, a tsunami, anything can be a triggering event. We will discuss all the possible progressive collapse that took place till now and we will also come out with a solution and better understanding towards the subject. Moving forward to Alfred P. Murrah federal Building, the building was located in the downtown of Oklahoma city, Oklahoma, US. It was, as the name suggests, United States federal government complex. The building was design...

So what is Engineering? Is it some clandestine clan of old people safeguarding the secret of the Universe from prying eyes? Or is it some fancy degree which can be fathomed by only a selected few who pass a scrutinizing test taken in few hours? Or is it some hocus-pocus black magic meant to be understood only by a selected few? For most of us this is the picture we have for engineering: Yes! Engineering is the sum total of the wisdom of many people smarter than us and we as students can only have a part of the knowledge, isn’t it? Ah, the good news is engineering is nothing more than physics. Yes, that is correct all that is around us is a direct result of applying simple (?) laws of nature. No, wait a minute, so does that mean that the buildings we see around us is a direct result of applying the laws of motion and not because of some high-tech code that the secret society of civil engineers have imposed upon the society...

First question comes to anyone's mind is, why the hell do we use steel as a construction material? What is so important about it? Well, the answer lies beneath the ground. Iron is one of the most abundant metal present on the planet. It is not very difficult to purify it and mold it in different shapes. Apart from it we can recycle the material very easily. This was the answer regarding it's availability. If you consider it from a strength point of view, well it is very strong and flexible. It is ductile too while helps in saving lives of thousands. It has got not strong but decent resistance against fire. Apart from it, the construction carried out using steel is pretty fast. As compared to a normal concrete structure, steel structure will take very less time to stand tall.  This was all about advantage of steel. Now lets talk about the behavior of the material. Why? Because to build any structure it is important to understand the behavior of the material. It is the mat...

Ductility and elasticity,the two most important terms that are discussed frequently in structural engineering. Elasticity defines about how much the material is elastic, that is to which extent the deformations are proportional to the forces applied on the material. While ductility defines the capability of the material to get itself stretched beyond the elastic zone. Let me explain this by taking a real life example. Take a two different material, a rubber band and a very thin steel or copper wire.  Pull the rubber with your hands by applying the force in exactly opposite direction, and force means a tiny amount of pull. You will notice that the mount of deformations caused by the small pull is very large, but when you leave the rubber band it will come back to it's original position. This means that the rubber band is elastic in nature. Oh, now you got something in your bucket. But wait, here comes the question. Till what magnitude of force can rubber band behave in such ...