3D Bows Notation....with a 3D sketch??

[nickcostin]

After much searching the web and my books...(I can't find the one I want)

I was wondering, it is possible to analyse a three element frame node using a 3D sketch. I can do Bows for 2D, and I'll wager it can be done using a 3D sketch.....but I just can't remember my 3D trig. I seem to remember breaking the input load down so there are two unknowns as in Bows triangle of forces??? If only I could find that bloody book....or my maths books of 40 years ago. :-(

I hope that's enough for the basis of a question.

Any links / help much appreciated.

Nick.

 

[nickcostin]

Has anyone even heard of Bows Notation?....or has FEA finally killed the fundamentals?? (rhetorical)

 

[CorBlimeyLimey]

"Has anyone even heard of Bows Notation?" ... Yes!

"I was wondering, (if) it is possible to analyse a three element frame node using a 3D sketch." ... I don't know & I'm presuming not many others (in this forum) know ... which is probably why there were no replies to your original post!

Try asking in one of the Structural forums

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

Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[handleman]

A link:

http://www.freestudy.co.uk/statics/prerequisite/frames.pdf

From what I can gather, Bows notation is more a bookkeeping method than anything. The same principle applies in 3D (vector sum of forces = 0). However, the trig is "triggier" in 3D. I assume you're treating your node as two-force members. The link above says to go "clockwise" around the node for labeling your vectors. Which way is clockwise in 3D? I think you'd be better off just summing forces in X, Y, and Z given that you know the directions of the three forces acting at the node.