3D Stiffness Analysis in MathCAD

[noratetoobig]

I have recently created a 3D stiffness analysis worksheet in Mathcad (It includes member end releases, member rotations includes 3d manipulative graphics display which also shows moments and shears for selected members) and has been checked with Staad pro output. The results from the Mathcad worksheet are near identical, if not exactly the same as the Staad output (generally any differences are attributable to round off with respect to member properties - Staad appears to sometimes produce slightly differing results depending on what method is used to extract properties data for input in the worksheet). For comparable results, the SET SHEAR command must be invoked in Staad since the worksheet doesn't include shear deformations which are gen negligible. The biggest challenge was getting the 3D graphics to work without plotting interconnecting joint members that don't exist. this was solved by plotting each member as a row of points, the density of which can be adjusted. the program works for structure up to about 1000 members and 500 joints.

Anyway, I attach a copy if anyone wants to test it out.

The attached file has internal structure database input by the user, which can take some space(matrices), however, for larger structures I have reworked the program to read from an excel file which can be uploaded if anyone prefers that way of input.

 

[MotorCity]

Looks pretty neat. Just curious, if you have access to Staad, what was the impetus to create the Mathcad worksheet?

 

[noratetoobig]

Since we only had a few Staad licenses in the office I wanted something simpler to use and because I have my own MathCAD license I didnt need to poach a staad license from my minions. Also, it gave me an insight into the workings of staad which uses the same methodology ie the direct stiffness approach. The only problem was for the checking of structure and load input where Staaad is much better due to the ability to select in the graphics environment, hence my drop down menus/lists for checking most parts which makes it more user friendly.

I have also written a worksheet for calculating all the Roark ring load cases. It can combine several at differeing angles of applied loads and produces graphic as well as tabulated results of shears moments and von-mises stress if you'd like a copy of that to review too.

 

[IRstuff]

Please refrain from double posting

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[noratetoobig]

Apologies IRstuff.

Since my posts were about MathCAD/Structural and Staad, I thought It better if I post on the forum subjects. I'll keep any future new subject posts to a single forum subject.