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 Building a popsicle stick bridge Post Reply Forum
 Posted by: Schmerdro ® 02/20/2006, 07:02:43 Author Profile eMail author Edit I have to talk to a civil engineer about how I can quantify when my bridge will break. My teacher said he knows somebody and 2 other students said the same thing but so far no one has received a response from them.So, this is what my bridge is going to look like: http://img157.imageshack.us/img157/3889/printscr6cb.pngThat's the side view. I would like to know if I hang a mass from the middle of the bridge, how is the force going to distribute itself if all of those triangles are equilateral? This mass will be increasing systematically (at a constant rate). So, basically, I need my dependent variable that will change with my independent variable (which is the mass hanged from the bridge).The bridge will be 57 cm long at the bottom and 45.5 cm long at the top. It will be placed on 2 desks that are 40 cm apart and I will be using hot glue.Since a bridge is supposed to distribute its load towards its extremities, I was thinking of placing the bridge on 2 mass weighters... and then the more those mass weighters will indicate (compared to the load that is actually hanged from the bridge), the more efficient the bridge is. Is that mathematically correct?Also, can you tell by just looking at my design where it will break? I'm thinking it will break here (in the red sticks, on the black area): http://img79.imageshack.us/img79/2381/printscr6cb8dn.png Because my top and bottom will be heavily reinforced and those 2 sticks will only be reinforced by 1 popsicle stick on both sides and they will be compressed. I'm not worried about tension because the hot glue is incredily strong and tcisk are more likely to break under compression than tension.

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 Re: Building a popsicle stick bridge Re: Building a popsicle stick bridge -- Schmerdro Post Reply Top of thread Forum

 Re: Building a popsicle stick bridge Re: Re: Building a popsicle stick bridge -- swearingen Post Reply Top of thread Forum
 Posted by: Schmerdro ® 02/20/2006, 07:33:00 Author Profile eMail author Edit Yes, I already have used that program.In the following picture, the red side will be supported by the object on which the bridge will be placed: http://img.photobucket.com/albums/v719/Lacadaemon/Bridge.gif So those chords at the end are pretty much meaningless."the red members you show on your second picture will not fail first" Then, assuming the bridge will not break at its joints, which members will break first? Modified by Schmerdro at Mon, Feb 20, 2006, 07:34:17