4. TRUSS Bridge Specs Weight, W ≤ 1.50 kg H+D ≤150mm Length, L ≤ 770 mm Height H ≤ 100 mm Span Length, between UTM supports S = 560 mm UTM Support Provide a 60 mm minimum flat bearing surface at the supported points (see sample bridges) Bridge Deck Width B ≤ 140 mm Top of UTM Depth D ≤ 50 mm
26. TIP 1 : if you want to efficiently use the strength of popsicle sticks, design your bridge such that tensile forces not compressive forces are developed in most of the members. “ Popsicle sticks are stronger in tension than compression because of buckling.”
27. You can analyze the truss using A structural analysis software.
28. TIP 2 : If you want to increase the capacity of the members against buckling, then provide braces.
29. Before Loading After Loading: No Horizontal Braces at the top. Buckling occurred.
30. TIP 3 : A deep hollow box girder is relatively light and has a larger flexural capacity.