FILENAMES: rvacuum2.mcd DESCRIPTION: This is a MathCAD worksheet to analyze a vacuum vessle. Posted by Fitch R. Williams . Fitch provided the following description: ======================================================================== Ok, this might be a fun thing and something new to start out the new year - the beginning of the quantative century (I can't spell mel ... malinn ... whatever, you know what I mean), in RCM (two years early if your a mathematician but what the heck - be empowered!), and an extension of our ability to communicate with each other using math (presented as a live useable but uneditable MathCAD version 7 worksheet and viewed using the free MathCAD explorer program - more about this below), which is the language of the physical sciences. (Its OK Jens, just take a couple of Excedrin and do math in the morining ) As an experiment, I have made up a simple MathCAD worksheet that has the "generalized" equation from Roark's Handbook that Peter Moss rightly thought he would have to scan in to present in this part of the NG. Its a lulu as you have the opportunity to find out. I posted it on the dropbox as rvacuum2.mcd (note there may be an rvacuum1.mcd there if Steve hasn't been able to delete it yet - DO NOT USE rvacuum1, it has an error in it (the final "r" is r^2 instead of just r) which I didn't catch in my excitement until after it was posted - I hate it when that happens. There is supposed to be a rvacuum2.txt file with it (with the body of this post as its contents, so if you have this post, you have the file) , but I have problems getting them to work - maybe this time? The over view is this. You go to http://www.mathsoft.com/mathcad/explorer/ and go through the process of downloading MathCAD explorer (free) and installing it on your computer - Ted, I don't think they have an OS/2 version :(. Its a huge download - 6+ Mb, but the great thing about this is that you can substitute in different values for the variables and see the results. Install MathCAD Explorer. Note: If you have Mathcad 7 or later you don't need it - but if you install it anyway, be sure to put it in a different directory than your MathCAD program resides in. Start it and take the tour, do the demo or what ever to get the feel of it. Then download the file mentioned above to your computer. You can use the File | Open | command in the ususal way to browse, find where you put it, and open it in MathCAD Explorer. Having done this you will be able to substitute in different values for the variables like length, thickness, radius, etc and see the results. The equation is nasty enough that doing it with a claculator more than once will be a drag, and each new value of radius, or length, or thickness, is recalcualated 20 times and plotted automatically to show the effect of node weakness vs buckling pressure. Hopefully, the worksheet will be well enough done, and simple enough, that it is self explanatory. I didn't not attempt to have it do a family of curves or anything else to complicated for this first demo. If this works, and there is enough interest in this method of exchange, we could end up with an online library of working templates related to RCM charter content, and of course anything else that for that this highly gifted group wants to explore quantatively. Its worth poking around on the Mathsoft WEB page www.mathsoft.com to see what the SW does. I'm not gifted to write a manual for it! Remember - not having a calculator in your pocket is "going unarmed". Fitch"armed and dangerous with MMS"Williams