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Re: Non Professionals doing Engineering[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: seaint(--nospam--at)seaint.org
- Subject: Re: Non Professionals doing Engineering
- From: Jim Kestner <jkestner(--nospam--at)somervilleinc.com>
- Date: Mon, 25 Jan 1999 11:57:27 -0600
Since we now have started to talk more about computers than professional vs. non-professional, let me add my thoughts.........
I believe that if you are an engineer using a computer program to develop an answer that you don't have a feel for, it is OK. This is the only way you will learn and develop some experience. It is up to your supervisor, who hopefully has that feel for the right answer, to look over your work before he stamps it and make sure the solution and the details look reasonable. If not then he needs to dig further. I do know, however, that the drawings can sometimes look good and the solutions may still be wrong.
We are all under so much time pressure today that I don't believe drawings and calcs are checked very thoroughly, if at all. When I started out, we had full time checkers. I don't know of any firms that have these anymore (depends on the size of the firm) except perhaps for major structures.
I do agree with you Barry about computerized preliminary tools not being available, but that is where us old guys can do things in a few minutes with a little hand figuring that a young guy using a computer program by trial and error might take a several days to do. A few examples that come to mind:
1. How many of you roughly know the size that a beam before you do the
2. Preliminary column sizes for multi-story buildings.
3. Upsizing members in frames to control drift. What is more efficient to upsize the columns or the beams?
4. Efficient truss depths and configurations.
5. Efficient bay sizes (dependent on loads, type of construction, cost of foundation (footings vs. piling), etc.
Jim Kestner, P.E.
Green Bay, Wi.
Barry H. Welliver wrote:
Without a doubt, computers have become a necessary tool for every structural engineering office. Sticking with just analysis needs, the ability to investigate alternatives in preliminary design is perhaps just one area underutilized at this stage of our evolution. For my part, I'd like more (better?) tools with preliminary modeling capabilities which help support early design decisions.
Others have discussed the garbage modes, accuracy hounds and other pit falls and I support these cautions. On the matter of knowing the answer before you ask the (computer) question I'm not so sure. Last week the SEA of Utah had Charles Thornton (Thornton-Tomasetti of NYC) speak on the design of high-rise structures. His presentation was very enlightening, even for a guy who spends most of his professional life working with wood frame and "low-rise stuff. Obviously the portal method of analysis won't cut it in this market, but I was taken by the speed with which he presented his information. Slides of construction, analysis, and test results all flashed by in tempo with his talk and very effectively gave us a good feel for what is involved in design of "modern" day skyscrapers. I felt there was a confidence in his work born not only from computer analysis, but also from the obvious years of involvement in this kind of design. Engineering judgment supported by computer modeling. I wondered about how well one could guess the results of a bridge connecting twin towers at the 42nd story. Or the cavern shaped bedrock profile directly below for foundation support. These are areas I'm unfamiliar with (I think I know my limitations) yet I trust they are magnitudes-of-scale differences for engineers practicing in these fields. Just as I needed to get my sea legs in designing for snow loads and avalanches to be able to eyeball solutions, I think engineers need time to develop their "bag of tricks". My caution is the speed in which we mature as professionals. Computers have laid opportunity before us to jump ahead in some fashion. How wisely we choose to use these help-mates is not something that will be regulated by anything other than the mistakes we might make in using them prematurely.
Oh, by the way, I applaud persons wanting to know how the computer designs for snow drifting. Its always useful to know if the "design program" has thought of everything. I trust someone pointed this individual to section 1644.
Barry H. Welliver
Jim Kestner wrote:I recently ran across this message on another newsgroup and it made me wonder if we are slowly losing control of our profession to non-professionals, especially with the advent of computer programs:
Hello, I design wood roof trusses and sometimes I need to know how big of a
drift will form on the trusses when there are two different roof elevations
next to each other. Up till now I had the design program do this for me. Now
I would like to know how to do it myself, and I can't seem to be able to
find a formula to do this. Any help would be greately appreciated, thanks.
This posting made me think about where our profession is going and the affect the computer will have on it. Are these trends good or bad? Is the EOR the Supervising Professional in this case? Does the EOR really have direct supervision as many codes require? I am sure a number of us have a few stories to tell about why this process does not always work well. All comments are welcome.
Jim Kestner, P.E.
Green Bay, Wi.
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