Thursday, February 19, 2009

Two Popsicle Stick Bridges from DLSU

I would like to feature two popsicle stick bridges submitted by my undergraduate students at the 5th DLSU-CES Bridge Building Competition. Bridge No. 09 by Morgan Say and Jet Tugado is a Warren-type truss bridge. It actually ranked no. 4 in both the Strength and Design category. The bridge has the properties, L = 626 mm, W = 1073 g (quite heavy). It's deflection at P = 10 kg was only 3.2 mm but at failure, it posted a very large deflection D = 19.20 mm. Again the arrangement of the diagonal members may have contributed to the large deflection. The diagonal members in this bridge are under compression. If only the weight and the deflection were reduced, it may have joined the top 3. Actually it is ranked no. 1 based on the P/W ratio only.
The second bridge (Bridge 16) by Jefron Gaw, Allan Mariano and Lex Alviar was withdrawn from the competition because its depth D exceeds the limit, making it impossible to test the bridge using two point loads. The bridge has an arch shape. The bridge is quite heavy W=1425 g. It is a well designed bridge and it may have performed well in the competition, if it only passed the specifications. The bridge was actually tested upto failure using the UTM and observe the failure mode - a bending failure at midspan.

I would like to commend the participants for creating the nice popsicle stick bridges. You are all winners!

9 comments:

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  2. this is soo cool!!!!!!!!!!

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  3. :) koo haha... makiNg
    ONE 4 SCIEnCE clASs hah:) neeD hElP:) lol gooD joB:)

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  4. doing one for science fair :D

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  5. oyyyy bout to red-eee for building bridge !
    hope i do gooood (:

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  6. I totally need to do this for my science fair project

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