When we travel to the LEGO Stadium at UCF

[twillybull]

The problem here is the unpredictable wave motion throughout the structure itself.  In buildings and moving systems, vibrations are never good.  Vibrations can be described as waves that pass through the object. 

Every material has a specific "natural or resonance" frequency.  When objects are vibrated at this frequency the vibrations (waves) tend to multiply .  Think of waves compounding on each other, if the peaks meet at the same time, they add to the height. 

When engineers design structures, they utilize different materials and passive and active dampening systems in order to minimize or break up the occurance of natural frequencies.  Unfortunately, many materials especially composites have numerous natural frequencies and no matter what, every assembly will have a natural frequency. 

The real problem here is the use of a "smart" driving force.  Since the students can feel the response of the structure and are purposely trying to invoke a wave motion through the structure, they vary their timing to jump and are actually FINDING AND FORCING the structure to vibrate at it's natural frequency.  Think of it as timing when you push your friend on a swing set.  You time it right to increase his speed / power.  With each pass he can get higher and higher. 

This is the real potential for danger.  They can keep increasing the height of the wave, until something fails.   

Structures tend to fail when forced to vibrate at natural frequency... every microscopic fatigue in building materials, every potential flaw in construction (ie loose bolts, bad welds) are being exposed to undue stresses.   

The Tacoma Narrows bridge is a very famous example.  You've probably seen an old black and white video of a bridge bounding up and down.  In that case, the driving force was the wind through the canyon.  The end result, the bridge was destroyed.       

With the existing perception of a lack of construction administration at the stadium (ie waterfountain scandal) the engineers would do well to rethink their initial response and take a long hard look at this.  I would also get rid of the song for now. 

[E.T.]

Video

[bulls96go]

i am going to the game in 2008...thank god we do not play them anymore

[Brad]

Video

Other than a bunch of derelicts jumping up and down, I can't see much...maybe the numbnuts with the camera could have held it still for a second?

;D

[Triple B]

Video

What are they saying? ........ It sounds like U-C-S-F.  :-\

[Economics_Nerd82]

Sounds like they are saying "U-C-F Sucks!"

and... well... I agree.

[outrunner]

UCF might be making headlines in the future with their stadium in a bad way.

Students at UCF said they want bouncing to become a tradition.

"Everyone seems more than happy with the stadium with zero concerns of safety," said Adam Papageorgiu, a UCF sophomore whose phone-cam video of the stadium bouncing was posted on YouTube under the title "The Trampoline."

Papageorgiu said fans have been bouncing to the Zombie Nation song since the stadium's debut game against Texas.

Darwin Award Honorable Mention

[kdawgy_orlando]

Jumpy fans worry UCF, but officials call stadium safe

Some frenzied football fans at the University of Central Florida are calling their new stadium "The Trampoline" -- and treating it like one.

Fans have discovered they can make the upper deck bounce by jumping up and down at once.

Their cue to go crazy: the techno-pop dance beat of Zombie Nation's Kernkraft 400.

"It's fun!" sophomore Michelle Martin says of the bouncing sensation that resulted in the trampoline nickname.

School officials say the stadium is structurally safe and ready for a capacity crowd Saturday when UCF takes on the University of Tulsa for the Conference USA championship.

University officials noticed the movement during the stadium's inaugural game in September against the University of Texas, said William Merck, vice president of administration and finance, who oversees campus construction. He said the motion caught them off guard, but that visual and electronic monitoring since the first game has revealed no damage.

Full Story here:

http://www.orlandosentinel.com/sports/orl-stadium3007nov30,0,4754238.story?coll=orl_tab01_layout

[outrunner]

already been posted and moved to State of Florida Board

[SRQ]

As a mechanical engineer, that statement by their student: "Added the mechanical-engineering student, "If I had no idea about this stuff, I would worry too.""  makes me wonder, WHAT IN THE ^#*% they are teaching their engineering students over there?  

This sounds like it's a potential resonance frequency problem... that can be a very powerful, very destructive and sometimes unpredictable situation.    

The Tacoma Narrows Bridge collapse is usually lesson one learned in any good vibrations or mechanics of materials class.  In that case it was the wind, but there have been other instances of bridge and other structure collapse do to the movement and vibrations caused by people.  This would concern me a great deal.  

Can never forget the video of that bridge twisting in the wind.

We can be sure that a bunch of drunk, bullet-proof college kids will do everything they can to reach a higher level of sway with each game.  Might be a good game to sit in the end zone.