Statics - You need to take this class

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Phil Graham

Honorary PhD
Mar 10, 2011
651
1
18
Atlanta, GA
We've now had a series of structures fall over, accompanying armchair quarterbacking, and too many erroneous things in "print." I'd like to encourage people to get serious about learning the basics of structural mechanics.

Your local community college will have "Statics" as a 2000-level engineering core class (i.e. part of the foundation for upper division engineering classes). Statics will teach you how to calculate the various forces at play in structures, like rigging, and remove a fair amount of the voodoo mystery of why structures are constructed the way they are. It won't make you a rigger, or get into the specific design of portable structures, but it will remove a lot of the mystery, and give you the proper intuition about how forces operate. You'll be able to calculate, rather than relying on "black magic" guidelines.

Your textbook will be a standard like Hibbler.

You will need high school algebra, trigonometry, and the barest amount of calculus (to calculate moments). You will need to understand vectors and vector notation. Statics has a lot of homework, but otherwise it is the easiest of the engineering core courses, and requires almost no advanced mathematics. Even if you never took calculus, the textbooks provide the formulae for moment calculations of common shapes that you can simply plug numbers into.

Take it pass/fail, sneak into the back row of the lecture hall, or find an online course. Puzzle over the homework problems with the budding engineering students.

It should be mandatory, along with an electrical power distribution class, for those in any way affiliated with live event production.
 
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Re: Statics - You need to take this class

Thanks for the link to Hibbeler's book. Ordered the 11th ed from eBay, $30 with shipping. Now to relearn how to use my calculator....

And thanks for being the voice of reason here.

Tim Mc
 
Re: Statics - You need to take this class

Is this what was generally called "statics and dynamics" or a subset of that only dealing with fixed forces?

I'm a drop out so never studied this stuff formally...

I recall an old thread about dropping road cases where there were moving parts to consider.

I guess the concept about rigging is that nothing should be moving.

JR
 
Re: Statics - You need to take this class

Best I can figure I took statics at the university of maryland in spring 85 and dynamics the following semester. It might be neat to go back for a review even though I have taught the very basic version in a couple of physics courses.
 
Re: Statics - You need to take this class

John Roberts said:
Is this what was generally called "statics and dynamics" or a subset of that only dealing with fixed forces?

I'm a drop out so never studied this stuff formally...

I recall an old thread about dropping road cases where there were moving parts to consider.

I guess the concept about rigging is that nothing should be moving.

JR
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Statics and dynamics are typically a two course sequence, though some schools (MIT comes to mind) cram elements of both into one.

The mathematics of statics is really straightforward. The math in the class is essentially (in vector notation): Force_A + Force_B = Force_C + Force_D applied over and over again. A little algebra re-arranges this into equations of the structure: F_a + F_b - F_c - F_d = 0. All the requisite equation of this type are then solved as a linear system. The trick is in learning where and how to apply the forces and/or couple moments, how to deal with moments inside beams, how to deal with statically indeterminate systems, and a few other bits. Even then, every lesson builds on the last, and the result is very logical to follow.

Dynamics involves solving differential equations (both ODE and PDE), and therefore is much more involved.

A technique to solve for the values of forces due to dynamic loads is to first calculate what the peak value, and direction, of the dynamic load force will be, and then apply that to an imaginary static system ("frozen" if you will) where a subset of the forces are the calculated dynamic loadings, rather than the (constant) force of gravity.
 
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Re: Statics - You need to take this class

I did a part of that when I was much younger then I got involved in restoring and building wood and fabric aircraft so I had to relearn it all again maybe tme to relearn G
 
Re: Statics - You need to take this class

At Cal Poly Pomona Statics and Dynamics were two different courses. Unfortunately I didn't stay in the program long enough to get that far. Those that took Harry Donavan's rigging class got treated to some good vector math basics. People working in that field need to know at least the basics.
 
Re: Statics - You need to take this class

Tim McCulloch said:
Thanks for the link to Hibbeler's book. Ordered the 11th ed from eBay, $30 with shipping. Now to relearn how to use my calculator....

And thanks for being the voice of reason here.

Tim Mc
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Glad you found a good deal on Hibbler's book. It's not exactly "for dummies" but it has enough explanation and lots of problems. I suggest purchasing a solutions manual, if you can find one. Worked solutions are the best way to learn the problems.

I think my voice of reason comes from the desire that the education level of the industry, globally, was sufficient that "we" could correctly discuss events such as this, rather than act as unintentional support for the voices that would add additional governmental regulation to the industry.

Also, I think a lot of people in pro audio will find statics to be right up their alley, and consider other engineering coursework as a result.
 
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Re: Statics - You need to take this class

of all the courses I took in university, Statics is probably the one I use (or refer to) most often.. and it's funny because most people have no idea what "statics" would be as a course.. usually I tell them it's physics (but really that was a course crammed full of electron theory and boring, less useful stuff)

Statics study will give you good tools for visualizing a structure, or anything as simple as a lever or simple mechanical problem and being able to deduce what is important, what is not, which part will break first, etc.
and we're not talking about all math here.. simple things like being able to tell which parts of a scaffold or structure are in tension and which are in compression.. (ie: which things need to be lashed together to keep them from coming apart, and which need to be physically strong enough to support that compression) this is why not every member in a bridge is the same thickness, and why some are cables and some are steel beams..

in terms of a stage, this helps to know 'if I push here (wind load), what does this structure have in place to handle that load'

and I agree with the OP. many universities will let you 'audit' a course, where you won't get credit but you can go and visit, and I think even do the exams.. if you have the time this would be cheaper than some audio industry courses, and probably just as useful..
I didn't do so well in calculus but I aced statics. anyone could jump in and learn. especially when you have practical examples in your head to relate to..

Jason
 
Re: Statics - You need to take this class

+1

I took the same math and mechanics classes as the MEs and Civils, it's eye opening to not only the structures and rigging, but to the entire signal path from the stage out the PA. I took up through multivariate Calculus, so if anybody is seriously going through the home study route and needs a hand with the math, PM me. I'll help however I can.
 
Re: Statics - You need to take this class

Tim McCulloch said:
And thanks for being the voice of reason here.
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Ppfftt...ghaahh...Well, geez Tim, you're taking all the fun out of the Internets.

Really though, I've spent so much time in a class room, that I'm actually enjoying being out working in the real world. Honestly, I just can't stomach being back in a college class room again, even though I do need to finish my degree at some point. (I actually still have occasional nightmares about being in class or failing a test or missing some big project).
 
Re: Statics - You need to take this class

At least when I attended Purdue some years ago (okay, many years ago), statics and dynamics were two separate, sequential courses. To perhaps put some perspective to this, I was one course short of applying for a second major in Structural Engineering and even did a Senior project in Civil Engineering, however I have never applied that outside the classroom and never felt myself qualified to assess or comment on structural conditions or solutions, one of those situations of knowing just enough to realize how much I don't know.
 
Re: Statics - You need to take this class

Justice C. Bigler said:
I do need to finish my degree at some point. (I actually still have occasional nightmares about being in class or failing a test or missing some big project).
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lol. those don't go away for a while.. even after having my degree framed and hanging on the wall I still had dreams that i missed some requirement and that they made a mistake and were going to revoke it :)

Jason
 
Re: Statics - You need to take this class

In my freshman graphics class we had a term project to build a balsa wood bridge, to cross a span... One way we could be graded was by how much weight the bridge supported vs, how much it weighed. It was an early morning class (that i rarely attended), and I threw together a simple structure (think triangles) the night before it was due... Of course i slept through the class it was due at, but they allowed me to test it at an afternoon section of the same course. Many didn't want their entire semester's work destroyed by testing, but i was not that attached to my odd looking creation... It didn't look much like a bridge, but it weighed less than 1oz and held 40#.. I got a B. :-) for a course I rarely attended (hey it was the '60s). I guess you could say I picked up a few thing along the way from working on cars, and two older brothers who were engineering majors.

Unlike most people studying this with little feel for the application, it seems people in the business working with rigging and temporary structures could get a lot from this field.

cover.gif


The pictures on the cover say it all... Statics it is...

JR
 
Re: Statics - You need to take this class

Ryan Lantzy said:
I was looking around on MITs Open Course Ware for Statics. Unfortunately, I don't think they have it posted. Maybe they just gave it a fancy name? http://ocw.mit.edu/courses/
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Ryan, they appear to have mechanics of materials 1 and 2, these are classes in sequence after statics. mechanics builds on statics to consider behavior of the underlying physical materials, which are merely treated as solid bodies in statics. Personally, I took statics mechanics and then materials failure as my undergrad sequence on structures.
 
Re: Statics - You need to take this class

I recall reading an interesting book about failures. Some interesting chapters on famous structure failures related to early iron and steel development, but there are other kinds of failures too (like systems and humans). I've always thought it was instructive to try to understand failure as well as success. I've been no stranger to both.

This book won't help you build stages, but was a good read.

http://www.amazon.com/Engineer-Huma...1_101?s=books&ie=UTF8&qid=1313608196&sr=1-101

JR
 
Re: Statics - You need to take this class

Every time engineering comes up I think of Isombard Kingdom Brunel, partly because the name is unforgettable, but because of this picture:
 

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