"Four, minus 4 over three, plus 4 over 5, minus 4 over seven. Dad!?! How many frikkin' terms do I have to bring this out to?"
"With a mouth like that...20."
"Aw! Jesus frikkin' Christ!"
"Thirty, then!"
Ah...memories. I shall enjoy them!
--Boothby
"The biggest cause of trouble in the...
Oh, goodness....you're one of those.
--Boothby
"The biggest cause of trouble in the world today is that the stupid people are so sure about things and the intelligent folks are so full of doubts." - Bertrand Russell
I did once attempt to punish my daughter (then 10) for something by making her sit in the corner and counting backwards from "pi".
Being as big as geek as I, she did:
"Three, point one four one five nine two...Hey!!!!
--Boothby
"The biggest cause of trouble in the world today is that the...
JAE,
Thanks for taking a look!
It's definitely a load-sensitive instability, but I don't think I have any slenderness issues with my elements. I DO think it's related to relative spring stiffness issues, since increasing the spring rate of the tension and compression springs seems to have...
Mike,
Fair question ("Make sure that the computer is plugged in?" and "First, can you make sure your friend is really dead") that I have asked people myself many times before!
Yes; the DL is non-zero.
I have since upped the TS and CS values by a factor of 5, and I got the Load Combination...
Add to that: The model DOES have Tension-Only Springs and Compression-Only Springs. I'm focusing my attention there...
--Boothby
"The biggest cause of trouble in the world today is that the stupid people are so sure about things and the intelligent folks are so full of doubts." - Bertrand Russell
I have a relatively simple model in RISA-3D. No "tension only" members. No "Euler Buckling" members. Spring constraints and some RIGID members, though.
It's got a few HUNDRED load combinations, and I'm trying to run ONE, using the "Solve Current Combination" command.
So far, so good...
The telescoping cylinder itsself will never see tension. It's purely a compression column.
But as I picture it, the cylinder walls NEVER see any axial compression! (Except maybe the top-most stage) Even the bottom-most stage doesn't carry any axial load--it's all hoop stress from the opil...
I started to examine a multi-stage telescoping hydraulic cylinder for Euler buckling (it actually is rigidly mounted at its base stage, and has side loads as well, so there are interaction equations to be dealt with), when I realised something important.
My "d'oh" moment of the day.
The walls...
Unless they've improved it (and I hope they have), AVOID the ASME study materials at all costs.
I bought their books & videos to study for the Mechanical ENgineering PE exam in NY. The ASME books were full of the same sort of errors that the Kaplan books were accused of having....missing...
Palm-based PDA's can also run a great little HP Calculator emulator. There's one less thing (again!) you have to carry.
But all the info you can store on these things is amazing! Plus phone. Plus Outlook. Plus Excel & Word & (so-so) PDF reading, Camera, Video, Dictionary, Avantgo (so you...
My boss told me something the other day that I thought was very helpful in being successful at whatever engineering job you have:
"Stop spending so much ^&%$%^&@ time on the Internet, and get some of your ^&%$%^&@ work done!"
:)
Simple cost calculation, I would think: cost of rustproofing vs. cost of multiple car washes (only count the "extra" washes after those snowstorms), measured out over the duration of the warrantee...
Has anyone ever done an ADAMS or other physics simulator simulation of all this, all the secondary (etc.) effects, loss of cable responses, etc? Or are we all discussing how many angels can dance on the head of a pin?
Stupid Question:
Assume (for the moment) that you have no drag or wind or standing or travelling waves on your cable. It's just a straight cable, running from the surface of the earth out to a geostationary satellite.
Where the cable starts, on the surface of the earth, is also a...
