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RE: Hand-Calcs vs. Computer Calcs

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In my opinion, you should always have a solid system of reviewing any
calculations performed by an analysis / design program. Looking through the
results, and making sure you understand what is going on with your structure
can usually catch any big errors in  any model.

Most of the time, computer programs calculate things very well....after all,
that's their job....to compute. The mistakes are usually made by the person
who creates the input. Remember...Garbage in, Garbage out. 

In general, I don't like to rely too heavily on commercial or proprietary
structural design programs. Sure, they can give you a good idea, but I like
to verify things my own way as well. I have found that spreadsheets provide
a great tool for this...you can easily track your steps, and you don't have
to worry about getting results from some sort of "black box".

A good rule to follow: The person using the program should know how to use
it, its advantages, and its limitations. The worst mistake is trying to use
a program for something  for which it was not intended. Check the program a
few times to make sure you agree with its results. These checks can range
from "big-picture" lateral global issues to small scale forces at a joint.
Whatever the case may be, check your output...running it past someone else
is also a great idea.

These are my thoughts.

> -----Original Message-----
> From:	Dave Adams [SMTP:davea(--nospam--at)laneengineers.com]
> Sent:	Tuesday, October 05, 1999 11:47 AM
> To:	'seaint(--nospam--at)seaint.org'
> Subject:	Hand-Calcs vs. Computer Calcs
> 
> Hello all.
> 
> I've had an opportunity to tutor high school kids in math & science (for
> about two-three years, part time) and was rather shocked to discover their
> reliance on calculators. Most classes require the fancy graphing ones,
> where
> all you have to do is plug in your equation and the calculator graphs it
> for
> you. I've seen problems that tell the student to "look at the graph and
> describe what it's doing" and that's about all. When I challenged them to
> plot the graph by hand (finding maxima, minima, etc.), many had no idea
> what
> to do. Once I taught them how to do it and encouraged them to ask their
> teachers to show them this, I could see a definite improvement in their
> understanding of how mathematic equations really work and a better
> understanding of what to expect with different powers of polynomials.
> 
> I've recently received a demo version of KeyLat and found it interesting
> that you could "...do lateral analysis on a two story home in as little as
> one hour!" with this software. I hearkened back to the "graphing
> calculator"
> debacle. Do you think there may be the potential of our profession
> becoming
> too "computerized"? I know full well that there are certain applications
> that require the use of sophisticated computer programs and that, in order
> to stay competitive, we need to do our calcs faster (computers help with
> that), but do we need to jump on the computer every time we need to design
> a
> simply-supported beam or a drag strut?
> 
> Now, to be fair, KeyLat producers do include statements such as "...the
> designer makes critical modeling and design parameter decisions" and that
> subscribers must be registered engineers or architects, but I'm just not
> sure this is a great direction to take the profession, especially for the
> lateral design of a two story home. Yes, the lateral systems in those
> structures can be quite complicated and tedious, but for a complicated
> system, doesn't it make more sense to be a bit more "hands-on"? Computers
> can help prevent (not eliminate) errors in calculations, but so can
> continual repetition of reasonable hand calcs and analysis of load
> transfer
> systems (hearkening back to the days of math flash cards and memorization:
> the more you do it, the more familiar things are and the better an
> understanding of how things work). KeyLat does appear to be a pretty neat
> program but, again, is this the direction we want the profession to move?
> 
> Maybe I'm way off base with all of these ramblings, but I'd like to see
> other's views on these things.
> 
> Regards,
> Dave Adams, S.E.
> Lane Engineers, Inc.
> Tulare, California
>