Work for Intern: Finite Element Concepts and Structural Analysis

[JGard1985]

Happy Friday Everyone

I have an intern starting in the office and am looking to teach him FEA. I'd like to teach him some basic FEA that correlates to real world structural analysis and design. I previously had an intern show the effects of bolt prying on wide flange shapes.

Anyway I'm looking for some ideas for FEA to have an intern work on that could be compared to using AISC code equivalent checks. Can anyone suggest some ideas for structural analysis and FEA.

Jeff

 

[dhengr]

JGard1985:
Why not have the intern do some real-world problems which you have already done? And, then have them check their work by hand with AISC code criteria, or other stds. and analysis means. Thus, you would already have a check on solutions which you thought were o.k., at one time. You could give them prelim. drawings, specs., client reqr’mts., etc., from your files, and let them dig out the data and info. needed to do the proper analysis and modeling, etc. Then, after critiquing their work, you can give them the orig. final design and calcs., etc., which they should study for any areas they came up short on, and for comparison and further discussions. This way, you are using a real-world problems, which young engineers seem to have no education in or knowledge of, rather than some secondary, minor detail, which they can look up in many good textbooks. Maybe, give them a current problem for a current client, which you have pretty well addressed before. Give them the previous calcs., specs., drawings, etc. to use as a guide for their new analysis, design and solutions, and let them have at it.

 

[WARose]

I have an intern starting in the office and am looking to teach him FEA. I'd like to teach him some basic FEA that correlates to real world structural analysis and design. I previously had an intern show the effects of bolt prying on wide flange shapes.

Anyway I'm looking for some ideas for FEA to have an intern work on that could be compared to using AISC code equivalent checks. Can anyone suggest some ideas for structural analysis and FEA.

Modeling connections would be misleading in many cases because you would likely get stress concentrations that would be ignored in most circumstances (i.e. where fatigue is not a consideration) in the code. Prying action (for example) is probably best covered by a spreadsheet.

For a newcomer, probably the best place to start is "stick" elements for floor systems. Get them use to modeling and fixing instabilities. Over time, you'd get them modeling whole buildings.

It just takes time, there is no silver bullet I can cram into a single post on eng-tips.com. One big question would be: what coursework has the "intern" had on this? He/she may not know how to model anything.

 

[DrZoidberWoop]

One of my favorite topics, when I was giving FEA workshops, was validating the Boussinesq soil pressure equations. It's simple geometry, correlates in a satisfying manner, and can be easily handled by first time users. Another good place to lead them with FEA is validating the effects of concentrated loads on flanges and webs in AISC J10. I did a fun thing on a lug located in a position causing eccentricity on the beam above (w/ ridiculous increase in deformation scale).

You should also make they immediately aware of the limits of FEA. I've seen plenty of seminars or presentations where the presenter quickly steamrolls the audience with a beautiful contour plot on a complex structure, with no way to validate. We always need to remind people that they must be able to defend every decision they've made within the program, otherwise they're just presenting visualizations, not proper results.

My photos are from when when I was big into using ABAQUS. Good times.

 

[human909]

Prying action (for example) is probably best covered by a spreadsheet.

I spent a good portion of a day trying to model prying action on an end plate because I was curious. Most of my modelling was riddled with issues. When I finally got the answer it was very close to my spreadsheet answer.... But for next time I'll know more how to model bolts in FEA. And for some of the work I do you really want FEA.

 

[DrZoidberWoop]

Another busywork kind of idea might be to have them validate the new equations in the AISC 15th edition manual for "Plate Elements Subjected to Out-of-Plane Loads," starting on page 9-14.

 

[r13]

Any design with computer generated outputs can be back checked by hand is the best project for the beginners, as he/she will learn both ways.

 

[dhengr]

JGard1985:
I was actually trying to get away from ‘busywork kind of ideas,’ young grads and engineers already know way too much about that kinda stuff. But, then they can’t even do that without FEA, and instead FEA is used to make it look important, perty and colorful, without having to do any real engineering study, thinking or having any real understanding of how the structure actually works. It is really scary that they are pretending to do any real engineering without a number of years of work under the wing of an experienced engineer and/or experienced engineering supervision.