Hello again,
It's Mid-August now, and the Rules have been out there for a month more or less.
As the first meetings, emails, and design sessions start to go down, just remember two things.
1. Do not suppress any ideas, no matter how unconvincing, whatsoever. Get the data first, talk about it in a reasonable sense, and make a decision. Case in point, the 2003 UC Davis Steel Bridge Team: Only beams won, and the Team jumped to the conclusion that a truss would be needed over the longer river. It was a bad decision, because the beam was considered, BUT NEVER ANALYZED. Now you look at the profile this year and may think a light, 7' truss will do the trick, but maybe a beam will work, or maybe it won't...either way GET THE DATA FIRST.
2. At some point you (Captains &/OR Design Heads) are going to have to stop the "paralysis by overanalysis" and make a decision to keep the project on schedule. If you go too deep into the numbers, and aren't sure what you want to build, then make a few key areas in the design, ie constructability or weight, and then just stick to your guns throughout the fabrication process. Committing early and completing the bridge to make mods and to practice will do way better than choosing the absolutely analytical best choice, because remember, you still have to build the thing, and the bridge + your construction crew have to perform to make it win.
That's it, design on :)
Thursday, August 17, 2006
Tuesday, August 08, 2006
2007 Design Notes
Profile:
There is obviously a big, wide open profile to design in this season. The deck window has been increased to 9" absolute maximum, and the overall height of the bridge can go upwards of 7 feet. So now there are the options: beam, multiple (3 or 4) beam, stacked beam, low profile truss, medium profile truss, or maximum profile truss.
beams:
Maximum depth for a one beam section (if you go "Double Black Diamond" on it) will be about 8 1/8" to be safe. A flat flange, like a square tube, or a bar flange, maybe you can get in the mid-7" range for depth. Is this going to be stiff enough? It just might be, based on the loading and the essentially 19 foot span ( approx. 2 feet shorter than the last two seasons). Always be aware of the killer S1 = 5,6, S2 = 1,2 scenarios, however, because they could quite frankly be worse than last season. 1300 lbs. per grate is not that small.
Multiple Beams
Because of the 1 foot by 1 foot footing box, there is possibility of loading up maybe 2 girders on each side. It's certainly nice for construction to have more liberty in the pier boxes - God knows Davis had some box issues on the construction site in Salt Lake City, like 7 issues.
Stacks:
Well, there is definitely the possibility of stacking a beam system. Either by doing it in a box or girderlike fashion in the 9 inch window, or going deep on the bottom layer of the stack, and then wide/boxy on the top to meet the 3'-9" necessary clearance. The connections can be complicated (see prev. post), so be wary of this design, because fabrication will be paramount more than ever to it's success in efficiency. You could also do a trip stack in the same fashion, but those connections are even more difficult. Big jigs needed. Remember the river too, can you reach 4-1/2 feet easily?
Trusses
If you do a truss you basically want to go as deep as you can, and try to keep the chords down to one piece each. In general, double piece chords aren't that great, because they can hinge/bend at their connection if in compression, unless they're very wide, and bolted/doved thoroughly. The double piece may be good if you intend on going for the full 7' with a pyramid truss or other "simple" truss type structure. The Warren Trusses that have been winning for the past 3 seasons, obviously provide the best structural integrity, but it may need to be skimped down to accommodate for better economy, and the presence of off center loads.
A Word on Loading:
Last season was basically a truck load, with the big weight at the front axle. Now it's more of a tandem load, with two equal, relatively large loads, closer to each other (at worst case scenario). This will alleviate that "arch like" kink at the center of the truss bridge somewhat, but not entirely. The kinks just move closer to the piers a little is all. Double measurement on the "left side" which could very well be the right side, if it's chosen that way. Asymmetry should not be a big design idea for most schools. The span is also about 18" to 24" shorter, and that more than anything, will stiffen up most of the bridges.
Construction Site:
Totally equal (except for the 30' and 15' run). The little barrier in front of the site, is going to make things trickier than last season where there was so much room to run! Now the tippy toes will be out again. The 9 foot river is not to big of a concern except for 4 member/node connections at center span. Reaching for things at 4 1/2 feet is a challenge even on your knees, and there's no room for economical error this year, so choose your profiles wisely and consider their constructability. That is it for now. Design on!!!
There is obviously a big, wide open profile to design in this season. The deck window has been increased to 9" absolute maximum, and the overall height of the bridge can go upwards of 7 feet. So now there are the options: beam, multiple (3 or 4) beam, stacked beam, low profile truss, medium profile truss, or maximum profile truss.
beams:
Maximum depth for a one beam section (if you go "Double Black Diamond" on it) will be about 8 1/8" to be safe. A flat flange, like a square tube, or a bar flange, maybe you can get in the mid-7" range for depth. Is this going to be stiff enough? It just might be, based on the loading and the essentially 19 foot span ( approx. 2 feet shorter than the last two seasons). Always be aware of the killer S1 = 5,6, S2 = 1,2 scenarios, however, because they could quite frankly be worse than last season. 1300 lbs. per grate is not that small.
Multiple Beams
Because of the 1 foot by 1 foot footing box, there is possibility of loading up maybe 2 girders on each side. It's certainly nice for construction to have more liberty in the pier boxes - God knows Davis had some box issues on the construction site in Salt Lake City, like 7 issues.
Stacks:
Well, there is definitely the possibility of stacking a beam system. Either by doing it in a box or girderlike fashion in the 9 inch window, or going deep on the bottom layer of the stack, and then wide/boxy on the top to meet the 3'-9" necessary clearance. The connections can be complicated (see prev. post), so be wary of this design, because fabrication will be paramount more than ever to it's success in efficiency. You could also do a trip stack in the same fashion, but those connections are even more difficult. Big jigs needed. Remember the river too, can you reach 4-1/2 feet easily?
Trusses
If you do a truss you basically want to go as deep as you can, and try to keep the chords down to one piece each. In general, double piece chords aren't that great, because they can hinge/bend at their connection if in compression, unless they're very wide, and bolted/doved thoroughly. The double piece may be good if you intend on going for the full 7' with a pyramid truss or other "simple" truss type structure. The Warren Trusses that have been winning for the past 3 seasons, obviously provide the best structural integrity, but it may need to be skimped down to accommodate for better economy, and the presence of off center loads.
A Word on Loading:
Last season was basically a truck load, with the big weight at the front axle. Now it's more of a tandem load, with two equal, relatively large loads, closer to each other (at worst case scenario). This will alleviate that "arch like" kink at the center of the truss bridge somewhat, but not entirely. The kinks just move closer to the piers a little is all. Double measurement on the "left side" which could very well be the right side, if it's chosen that way. Asymmetry should not be a big design idea for most schools. The span is also about 18" to 24" shorter, and that more than anything, will stiffen up most of the bridges.
Construction Site:
Totally equal (except for the 30' and 15' run). The little barrier in front of the site, is going to make things trickier than last season where there was so much room to run! Now the tippy toes will be out again. The 9 foot river is not to big of a concern except for 4 member/node connections at center span. Reaching for things at 4 1/2 feet is a challenge even on your knees, and there's no room for economical error this year, so choose your profiles wisely and consider their constructability. That is it for now. Design on!!!
Wednesday, August 02, 2006
2006 NSSBC Awards - "As a Cal Aggie observer saw it."
Okay, until we manage to set up a self-controlled website on ucdavis.edu through the Dept. this blog will just have to serve. The picture, linking, and overall presentation capabilities for Blogger are a little bit limited, but nothing can replace good writing...so this may really suck.
The first will be the most boring, but most meaningful ones, and rightly named:
AWARDS THAT ACTUALLY MEAN SOMETHING
1st Place - North Dakota State University
You can't say enough about the Bison of Fargo, ND. We nickname them "The Borg", because each year they have a flawless structure and always seem very soft spoken and highly organized. This year was no exception as they walked away with the most necessary award of '06, that being Structural Efficiency. Hats off to NDSU, 4th NSSBC Championship, 3rd in 5 years...I guess so long as it's not a Structural Efficiency dominated competition with Nationals in around the Midwest, other schools have a chance ;-p.
2nd Place - SUNY Canton
A Team of evolution and emergence in the past 5 years much like UC Davis, the North Stars now have something to cheer about besides their hockey team. Their first national placement (???we believe???), and plenty of hardware on top of it, Canton deserves tons of credit for giving NDSU a real run for their '06 money. This 2nd Place follows a steady 5th Place showing right behind NDSU (4th) from 2005 in Orlando.
3rd Place - University of Wisconsin, Madison
Badger, Badger, Badger, Badger, Badger, mushroom, mushroom! After the agony of a 2005 failure, the pesky critters from up north turned in a dandy at Salt Lake City. The workmanship completed at Endres looked superb, as well as the high velocity builders during the big show. They were almost running too fast, as they had make a few glove saves along the way. That concrete in the Salt Palace was a bit slippery. Didn't make it to Slappy Chest, but we do remember...Cannonball!!!!!!
The first will be the most boring, but most meaningful ones, and rightly named:
AWARDS THAT ACTUALLY MEAN SOMETHING
1st Place - North Dakota State University
You can't say enough about the Bison of Fargo, ND. We nickname them "The Borg", because each year they have a flawless structure and always seem very soft spoken and highly organized. This year was no exception as they walked away with the most necessary award of '06, that being Structural Efficiency. Hats off to NDSU, 4th NSSBC Championship, 3rd in 5 years...I guess so long as it's not a Structural Efficiency dominated competition with Nationals in around the Midwest, other schools have a chance ;-p.
2nd Place - SUNY Canton
A Team of evolution and emergence in the past 5 years much like UC Davis, the North Stars now have something to cheer about besides their hockey team. Their first national placement (???we believe???), and plenty of hardware on top of it, Canton deserves tons of credit for giving NDSU a real run for their '06 money. This 2nd Place follows a steady 5th Place showing right behind NDSU (4th) from 2005 in Orlando.
3rd Place - University of Wisconsin, Madison
Badger, Badger, Badger, Badger, Badger, mushroom, mushroom! After the agony of a 2005 failure, the pesky critters from up north turned in a dandy at Salt Lake City. The workmanship completed at Endres looked superb, as well as the high velocity builders during the big show. They were almost running too fast, as they had make a few glove saves along the way. That concrete in the Salt Palace was a bit slippery. Didn't make it to Slappy Chest, but we do remember...Cannonball!!!!!!
SUBJECTIVE AWARDS (WE DON'T COUNT UC DAVIS)
f.y.i. - No rankings here just mentions, as most of these categories are subjective.
BEST TOOLS - CONSTRUCTION DESIGN FEATURES
Ecole de Technologie Superieure (ETS) - That crazy counterweight for their piers, wtf eh?
NDSU - self tightening bolts over the river - gutsy move - and now proven effective.
Wisconsin - The "ubermallet" for the doves over the river - very nice.
BEST TOOLS - CONSTRUCTION DESIGN FEATURES
Ecole de Technologie Superieure (ETS) - That crazy counterweight for their piers, wtf eh?
NDSU - self tightening bolts over the river - gutsy move - and now proven effective.
Wisconsin - The "ubermallet" for the doves over the river - very nice.
BEST FABRICATION - AESTHETICS
Clemson
NDSU
Wisconsin
UC San Diego
SUNY Canton
Gonzaga
Missouri KC
Lakehead
Lawrence Tech
Georgia Tech
Chico State
FATTY TRUSS AWARDS
Wisconsin
Clemson
Texas A & M - College Station
SUNY Canton
BEST DECKS/CONNECTIONS
UC San Diego
SUNY Canton
NDSU
Lakehead
Southern Poly.
NJIT
Clemson
Wisconsin
BEST STEEL BRIDGE WEBSITES (NSSBC NOT REQD)
Wisconsin - no competition
Florida
Ohio State
Hawaii
Illinois Inst. of Technology
Penn State
South Dakota State
MOST IN NEED OF A DECENT/UPDATED WEBSITE
Georgia Tech
Oregon Inst. of Tech.
Tennessee
SUNY Canton
Southern Poly.
San Jose State (you're in Silicon Valley people)
University of North Dakota
Hudson Valley CC
University of Michigan
Lawrence Tech
Alaska Anchorage
Akaska Fairbanks
BEST NEWCOMERS
University of North Florida
Hawaii
UC Berkeley
Gonzaga
BEST OF THE WEST
UC San Diego
BEST OF THE EAST
SUNY Canton
BEST OF THE MIDDLE
NDSU
BEST SPIRIT
Wisconsin
Clemson
HOTTIE AWARD
NJIT
WISCONSIN
SAUSAGE FACTORY AWARD
NDSU
MOST LIKELY TO KICK ASS NEXT YEAR
FLORIDA
MICHIGAN
LOUISIANA STATE
IOWA STATE
PENN STATE
NDSU
CSU NORTHIDGE...
*IF YOU HAVE ANY COMMENTS, NEW CATEGORIES, OR THINK THAT SOMEBODY'S BEEN FORGOTTEN, YOU'RE PROBABLY RIGHT -- SO LEAVE YOUR COMMENTS, AND KEEP THE NSSBC FEVER HOT ALL YEAR LONG!!!
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