OK, my science project is due on Thursday and I have got to know which type of Truss bridge is the strongest!! THe Kingpost, the queenpost, or the Howe???? Please help me!!!!!!!!!!!!!!
2007-03-13 11:24:42 · 3 answers · asked by Aj 1 in Science & Mathematics ➔ Engineering
To a certain extent, truss bridges support loads by resisting "bending" forces, or "moments." Therefore, the "stiffness" of a truss is the most important factor.
Both the King-post and Queen-post designs are inferior, because they have significant central joints that tend to act as "stress-raisers." Their structure is also too open to efficiently provide stiffness.
The Howe truss is better, but such "box trusses" tend to be overbuilt in order to provide sufficient stiffness in the center, thus adding excess weight. Also, the structure is too open near the ends, where resisting "shear" force becomes important
In my opinion, the "Bowstring", or "Arch" truss is the strongest, since it's contains no irregular joints, and it's width is greatest in the center, where bending force is also the greatest. It's structure is also "tighter" at the ends in order to provide more shear resistance.
http://okbridges.wkinsler.com/photos/birdcreekbridge4g.jpg
Good luck
~Donkey Hotei
P.s. here is arguably the most famous truss bridge in the world, the picturesque "Forth Rail Bridge":
http://image02.webshots.com/2/6/71/81/48567181QrkCZh_fs.jpg
2007-03-13 12:43:38 · answer #1 · answered by WOMBAT, Manliness Expert 7 · 0⤊ 0⤋
It is all in the quality of the construction. You are not a good enough craftsman to tell which design is best.
2007-03-13 18:36:30 · answer #2 · answered by Mikee 3 · 0⤊ 1⤋
Sorry, Pal. My area is electronics, instrumentation, and embedded control systems.
Doug
2007-03-13 19:02:34 · answer #3 · answered by doug_donaghue 7 · 0⤊ 1⤋