Falling Brick Problem 6

[SteveGregory]

Could someone tell me how to calculate the force of a brick falling 30 feet and what kind of damage I could expect on 2 layers of plywood? The plywood would be used to protect some translucent fiberglass roof panels.

 

[vandede427]

Wow, this thread has been going on for over a month.

Why don't you call-out some really good brick ties so they don't fall off the building in the first place?

 

[mark1234]

vandede427,

LOL...

3/8" plywood would stop the brick. There are no numbers that should be applied to this situation.

MDJ

http://www.windspeedbyzip.com

http://www.groundsnowbyzip.com

 

[csd72]

Steve,

This is first year dynamics, any good text will cover it.

 

[jedward]

Simply absorb the energy of a falling brick by 2 or 3 layers of 1/4 plywood separated by , say, 1".The plywood should be "loosely" supported at a few points. The impact will be distributed in the sheets.
A large number of bricks simultaneously could be a problem.
This is the principle behind micrometeroid shields used on some spacecraft (aluminum or plastic sheets separated)

 

[bigmig]

It is amazing to see the mind of engineers make a simple problem so complex. Again and again I read problems and solutions on this website that disregard a big part of what we all do: economics. I realize that alot of the previous posts are tongue in cheek and I admit are very amusing. What I haven't noticed is the otherside of the story, i.e. the guys in the field who called the engineer to say "We might have some bricks falling below, what should we put down?". The cost of two a 3/4" rated panels..heck make it 3 layers = approx. $90. The cost of loosing the glass that is being protected = much more than $90. The cost of my entire crew waiting 1 day for the engineer to tell me that 3/4" panels are more than ok = more than $90....I think everyone gets the point.

 

[drawoh]

Drop one brick. Look.
Step sideways
Drop two bricks. Look.
Step sideways.

Drop three bricks.

...

racookpe1978

This is the scenario I was refering to in my post. At some point, someone is going to implement jheidt2543's suggestion to cause the bricks to stop dropping. Whatever has been put in place to stop falling bricks is going to have to stop you as well.

JHG

 

[vandede427]

somebody please put an end to this thread.

 

[SteveGregory]

Thanks everyone. Go home now and enjoy your weekend!