earthquake proof.

[dragonstar57]

I have to build a scale 6 story model tower with 4-6in per story to survive on a shake table (to simulate a earthquake) out of raw spaghetti noodles and hot melt glue. 100 gram weights will be placed on the 2nd 4th 6th floors.

I need to know how to calculate the forces that the model will endure and the strength of the model.

i was thinking of incorporating the following design features.

cross braces (forming triangles)

have the tower tapper in from the base until it reaches the 4th floor where it will stop tapering and continue at the same width. I need to know if these will help.

we are also supposed to build a base isolation system idk enough about the materials that will be provided to talk about that yet.

Edited November 30, 2011 by dragonstar57

[imatfaal]

I am not an expert on this (although I entered a few comps at school and uni). I would draw a very simplified model of my proposed construction and label where the forces (big/small tension/compression/sheer positive/negative reinforcement) are with no lateral motion. You will need to know the best ways of your spaghetti dealing with forces and under what forces it it weak. then redo your diagram with the introduction of a lateral force - bear in mind the top weight only moves because the motion of the table is "communicated" to it by the motion of the pasta that connects it to the table

 

If you wanted to be slightly outre you could try isolating the weights from the tower; suspending each weight from the rigid frame (but cannot see how to get enough flexibilty from pasta and glue to make suspension viable), build a platform for weights and mount on rollers (ie lengths of spaghetti) in two perpendicular directions. i would have thought that anything that isolated damped or reduced the motion of the weights as opposed to the structure would be a good thing.

 

If the table just shakes from side to side (ie no up and down) you could just try isolating the whole tower; a flat bottom and a series of layers of loose spaghetti, with each layer having all strands parallel, but every layer at a perpendicular angle. With a few layers I reckon your tower might just stand still(ish) whilst the table wobbles furiously underneath it . Similarly break up a couple of packets of spaghetti and build tower on a bed of that - very messy though ;-)

 

I think I might have written too much for this forum, - but as I am merely an interested and slightly crazy amateur I don't think the above even comes close to breaking the rule.