Completely O/T - minimum weight structures
Posted 05 April 2013 - 02:08
Posted 05 April 2013 - 11:05
Posted 07 April 2013 - 00:24
A famous structural engineer once said that the worst thing that ever happened to the analysis of structures was when the idle French mathematicians of the 18th and 19th century got involved.
Didn't understand a word...
It is true that you can get amazingly good results in both structures and statistics (another playground) by sticking to basics and approximating.
But, if you want to know what a minimum weight structure would actually look like, that paper tells you.
Posted 07 April 2013 - 03:39
The Michell structures at the end remind me very much of the "iron bridge" at Ironbridge. I don't know if the "iron bridge" structure was calculated (certainly calculus and mathematics were pretty advanced by 1779 when the bridge was built) - or it was built by the "that looks about right" method.
Posted 07 April 2013 - 09:32
A lot of steel/iron bridges are the same. They carry probably 3 times the weight originally envisaged.
There was a TV series, 'mighty structures' or similar that showed the building of some of these, it also showed the failures.
In my area the 'engineers' have built major and minor bridges that have lasted less than 20 years. Concrete and steel which have spalled terribly. One was load limited at 2 ton, after walking under it I advoided driving over it!
The major one over the Murray had a 3 tonne limit and the trucks were going 30km out of their way to go around it. This on the main road to the Riverland and Sydney. That was a very major 'Ooops'
Posted 07 April 2013 - 10:37
Posted 07 April 2013 - 14:03
I am a bit surprised to see that the members in the Michell structure (Fig.28) are curved - I would have thought straight would be stronger - unless maybe they wanted to use as few joints as possible and long one-piece members.
I can see applications in bridges and buildings etc. - but in cars?
Posted 07 April 2013 - 22:14
and also my lecturer, or JE Gordon, who wrote the two books on Structures and Materials that everybody who is interested should read.
I'm guessing it was Gordon.
Posted 07 April 2013 - 23:37
Yes, Heyman's lectures were very popular, even the architects turned up for some of them!
did you go to uni there?