dann2707 Posted January 26, 2012 Report Share Posted January 26, 2012 (edited) Hello. Basically, one of my modules in Uni is called proffesional studies. It's so far basically getting people to work together in teams effectively and all that nonsense you probs work on at work team events lol. One of our challenges for two weeks is to make a bridge out of paper that can hold the most weight in the middle, weights will be added gradually until they collapse. There are around 36 groups we will be fighting against. We can use any means to get info on how to make this bridge so im asking you guys as I know we have a few engineers on here and hopefully that might come across with this? The criteria is : • Max amount of 12 a3 sheets of paper • Max use of two tubes of pritt stick glue • The tables are 0.75m apart. We can't glue the bridge down ontop of the table. • There is a 0.25m permissable area from the edge of the table from which the bridge can rest on. So 0.25m excess on each table (if I haven't worded that right ill upload a pic). • The weight will be placed directly in the middle of the bridge If anyone has any ideas on this it'd be awesome! Dan. Edited January 26, 2012 by dann2707 Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted January 26, 2012 Report Share Posted January 26, 2012 Tubes. It's all about tightly rolled tubes. And triangulation. It's all about tubes and triangulation. And thinking it through first. It's all about tubes and triangulation and thinking it through first. Quite like this for a simple solution but doing it over a larger gap with overlaps may be tricky: Also quite nice with the reinforcements at the corners. What about using some water together with some dissolved pritt stick and shredded paper as well to create some kind of paper mache type reinforcements... Quote Link to comment Share on other sites More sharing options...
dann2707 Posted January 26, 2012 Author Report Share Posted January 26, 2012 Interesting, i need to properly think this through. Also edited original post. Weight will be placed directly in the middle of the bridge. Quote Link to comment Share on other sites More sharing options...
bikeperson45 Posted January 26, 2012 Report Share Posted January 26, 2012 Would that work the same with the weight just in the middle though? And paperclips, disqualified Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted January 26, 2012 Report Share Posted January 26, 2012 Would that work the same with the weight just in the middle though? And paperclips, disqualified Paperclips can be substituted for pritt stick and paper folded over the open ends. With the weight in the middle it may struggle but depends how far you can make the paper stretch. If you could enclose the section to make it box section (or add further longitudinals in conjunction with the two lateral beams it may work better too. Quote Link to comment Share on other sites More sharing options...
chris4stars Posted January 26, 2012 Report Share Posted January 26, 2012 (edited) how about one larger triangle with some way of hanging the weights from the apex at the top? will focus the forces to compress each side, and if built right...that could be a fair amount? if you were able to figure out a way to 'wedge' the bridge, so that each side of the bridge was on the edge....would mean you could use 6 pieces of paper on each side and make a pretty strong beam! *edit, actually measuring the distance, and the length of the 'beams' my idea wouldnt be the best...it would defiantely need multiple triangles to make up for lack of 'horizontal strength' for want of a better description SO.. a scaled down version of this.... Edited January 26, 2012 by chris4stars Quote Link to comment Share on other sites More sharing options...
RobinJI Posted January 26, 2012 Report Share Posted January 26, 2012 (edited) Time for paint I think: Just a very simple one without too much thought, lol. Should be pretty tough as long as it's glued well. Actually looking at it, I wouldn't put the corner of the cut outs at the ends right in the joint, maybe ~1cm bellow it. Oh yeah, and stick the bits you've cut out of the ends over the cuts in the corners Edited January 26, 2012 by RobinJI Quote Link to comment Share on other sites More sharing options...
shamus Posted January 26, 2012 Report Share Posted January 26, 2012 (edited) Most successful one when we did this had a reasonable design but meticulous care in its construction. making everything identical so there's no weak link is crucial. Three rolled tubes with thin strips wrapped around at mid, quarters and ends seemed popular and effective. although a circular cross section is far from perfect, any out of plane shape or load will lead to bucking as one part of the face yields. You'd want the wider face of the 'triangle' cross section on the compression face. As for the base, a few strips glued together is fine, its there to hold the tensions and provided you can secure it to both stanchions the paper is pretty good in tension. The paper mache joints idea is quite good and i would recommend a trial. but probably costly in paper? its all about surface area and reinforcing the compression side to avoid it causing bucking in the circular sections. adding small inserts inside the tubes would be a way round this. folded flats inserted vertically inside to protect the venerable compression face. Last but not least the twin uprights, starting spread out, meeting at the top the spreading back to mid span. Has to be symmetrical and does put a not of compression on the cross spar. this will have to be the stiffness part otherwise it will simply fold into the middle. Edited January 27, 2012 by shamus Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted January 27, 2012 Report Share Posted January 27, 2012 would you do Anna Gu? Quote Link to comment Share on other sites More sharing options...
Danny Posted January 28, 2012 Report Share Posted January 28, 2012 Are you allowed to take the pritt sticks apart? ;-) Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Well the comp was today and out of 30 groups there has been 15 gone so far we are bossing it! Ours held 40kgs, the highest anyone else has got was 22kg then other than that one they are all on around 7, 8 kg. The record at our Uni in this module was 33kg so weve beaten that! Quote Link to comment Share on other sites More sharing options...
trials owns Posted February 13, 2012 Report Share Posted February 13, 2012 Pics or it didn't happen Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Ive filmed it all haha Quote Link to comment Share on other sites More sharing options...
N.Wood Posted February 13, 2012 Report Share Posted February 13, 2012 Well the comp was today and out of 30 groups there has been 15 gone so far we are bossing it! Ours held 40kgs, the highest anyone else has got was 22kg then other than that one they are all on around 7, 8 kg. The record at our Uni in this module was 33kg so weve beaten that! I bet the bitches panties were dropping left right and center! 6 Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Haha damn right. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Came 2nd overall! We won on the mass carried but they won on weight of the bridge! Gutted but we still hold the unis record woop. Quote Link to comment Share on other sites More sharing options...
monkeyseemonkeydo Posted February 13, 2012 Report Share Posted February 13, 2012 they won on weight of the bridge! That sounds a bit crap! Was it worked out as mass carried/bridge mass to give a measure of efficiency? If it was just bridge mass then that's lame! Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Yeah thats it. Ours weighed 192g and held 40kg Theirs weight around 126g and held 26kg. Which funnily enough gave the same ratio as us but as theirs was lighter, apparently that was the decider and they took it. Dicks! Haha oh well it was still all fun. Quote Link to comment Share on other sites More sharing options...
Muel Posted February 13, 2012 Report Share Posted February 13, 2012 The measure of a good bridge isn't strength to weight, it's whether a fat bloke in a big truck can drive over it without getting wet feet. 2 Quote Link to comment Share on other sites More sharing options...
JD™ Posted February 13, 2012 Report Share Posted February 13, 2012 Yeah thats it. Ours weighed 192g and held 40kg Theirs weight around 126g and held 26kg. Which funnily enough gave the same ratio as us but as theirs was lighter, apparently that was the decider and they took it. Dicks! Haha oh well it was still all fun. Don't those figures make you the winner in both though? Yours holds 208.33x its weight, and theirs held 206.35x. A small victory, but a victory nonetheless. I'm assuming you've rounded somewhere though and that the numbers came out different - must've been close! Quote Link to comment Share on other sites More sharing options...
Muel Posted February 13, 2012 Report Share Posted February 13, 2012 Slow day Jason? Got to fill it with maths to entertain yourself? Quote Link to comment Share on other sites More sharing options...
JD™ Posted February 13, 2012 Report Share Posted February 13, 2012 Slow day Jason? Got to fill it with maths to entertain yourself? Head's gone back to not working for work, so I'm currently sitting at my desk hitting cmd+r on the 'View New Content' page and numbly hitting 'Stumble' on stumbleupon. Productive. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 Yeah theirs might have weighed a little less JD, was off the top of my head. Still a bit gutted though but oh well haha Quote Link to comment Share on other sites More sharing options...
RobinJI Posted February 13, 2012 Report Share Posted February 13, 2012 Gutted, what design did you go for in the end? It seems a bit weird that they'd restrict the materials, and then penalise you for yours weighing more, surely that's just making use of your full resources? They didn't make use of them and made a bridge that wouldn't take as much weight. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted February 13, 2012 Author Report Share Posted February 13, 2012 This is it during the comp. Back home now so I can explain it a bit better. Basically two legs at either side and at the bottom of these are little cut outs to wedge in the table. These consisted of super tightly compacted a3 sheets. The the top part was like a beam that went across, and within that we used 6 tightly rolled paper, in like a 3, 2 1 We wedged the legs into the top beam at around 55 degree angles. The vid will be up later. its ace. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.