My commitment to the real world

The more I write in this blog, the more I realise what is important. I called it engineering for the real world, but now I realise the emphasis should be more on the real world and less on the engineering. I am an engineer and I think like an engineer but what I want to write about is the real world, the world that we all live in, for better or worse.

A few years ago I watched a documentary on how soilders are trained. The premise of the film was that most people do not have a natural instinct for killing, they have to be trained to do so. And the training that a soldier has to go through to create the natural killer instinct fundamentally changes the people that they are.

Of course, all this training must come at a price, and for soldiers it is a heavy one. The training does have an effect on who you are as a person and more importantly what your natural reaction to a situation is. This is by no means exclusive to the military, intense training affects us all as people. Many recruits probably don't realise this, but by agreeing to train as soldiers, they are making a huge sacrifise, not just potentially their lives, but they are allowing their nation to turn them into machines of war and in doing so change who they are as a person. It is of course not all negative, there are many benefits to becoming a soldier, but for those who have not been in the military I think it is important we remember all of the sacrifises that soldiers and their families make to protect our nations. Since watching the documentary I have always supported soldiers no matter what my view of the conflict they are engaged in, because of the sacrifise that they have made.

This morning I watched a TED talk by Deborah Scranton. She is a documentary film maker who has been creating a film covering the conflict in Iraq. This talk made me realise something, I have always said that I have supported soldiers, but to say something, and to make the commitment to do something are two different things. It is so easy to be a well meaning person saying that you believe strongly in this and that, but does this actually mean something unless you actually do something about it. It might not have to be something particularly special or important, but I think only by doing something can we demonstrate our commitment.

I feel now that I need to go out and do something for returning soldiers. It might not be much, but I have to demonstrate my commitment to myself, I have to find out if I am truly committed or if I need to reassess the way that I view the army and the people who work within it.

The talk by Deborah is really compelling. I'm not going to discuss the rights and wrongs of the wars going on around the world, but this is a film that is worth looking at for everyone. Whatever your point of view it does demonstrate what the soldiers are going through, and if demonstration is ever needed that soldiers in a conflict zone are not just doing their job, this film is it. It is a cliché, but this talk is so compelling that the silence is deafening.

The background to numerical models

'How important is it to understand how a numerical analysis programme works in order to use it for design?'. I guess if you asked any engineer this question the answer would always be very. But if we asked if those same engineers understand the analysis programmes that they use for design, we might get the answer no more often than I think we would find comfortable. It's an uncomfortable truth about the industry we work in.

When I ask myself the question why this should be the case I personally can't come up with one answer. One obvious reason would be that so many users are self taught when using analysis programmes. The documentation, especially covering the theory, is often poor and as usual the training of the user is also limited if it actually exists at all. Learning the theory behind a program is often very difficult and can be very mathematical..... but that doesn't mean you have to learn this hard maths to understand how a program works.

To prove this I want to consider a numerical analysis programme called UDEC (ref 1.). This is a very powerful tool, typically used for analysing two dimension rock mechanics problems such as rock slopes or tunnels in rock. The image shows a typical analysis of a tunnel in rock showing how the programme can analyse complex joint patterns in the rock around the excavation. So how does it actually work?

Rather than quoting the extensive manual, going into the finite difference method in detail I am going to give a very quick and dirty explanation of how it solves the problem. The solution method used by UDEC is basically to apply Newton's laws of motion to each block, zone or other structure within the model. From this an acceleration can be determined for each element. By considering very small time steps the gradually movement and straining of each part of the model can be calculated. Once the small movements and strains have been calculated for one time step, the resulting small changes in the contact stresses, stresses within blocks and any other forces on the model can be calculated. These forces can then be applied to the elements within the model and the acceleration and displacement can be calculated for the next time step. The model steps through time slowly until a solution is reached i.e. the out of balance forces within the model tend to zero.

That is all there is to it. It doesn't mean if you know this, you are ready to use the programme in anger. There is a lot more theory to learn, but that theory doesn't have to be mathematical. The problem is that it is finding non-mathematical explanations of the theory is difficult. If we can get more explanations of how things work without being too mathematical I can only see this as being a positive.

If you have any explanations for how things work or find any please post them here so that we can all improve our understanding of the tools we use.

Ref 1 - UDEC (Universal Distinct Element Code), HC Itasca