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Re: asd vs lfrd

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terrence turner wrote:

>         I was wondering why allowable stress design is still being used in
> the United States.  I am a practising structural engineer in Canada and have
> [...]

> so can somebody clue me in on the advantages and disadvantages between the

LRFD, at least as I've seen it implemented by AASHTO, is heavily
computer-intensive, and the computer programs to apply its techniques don't
exist yet.  Also, as others have mentioned, the "overhead" of learning a new
code weighs pretty heavily on those of us who are quite comfortable with ASD and
LFD.  We just don't want to have to take the time, or really have the "down"
time to spare, to spend learning another code.  And in my own case, I find that
LRFD allows much less of an intuitive "feel" of how the structure's behaving,
but that may just be chauvinism on my part.

> two systems? Also I am wondering why you have so many exams to become
> [...] related to engineering.  Many people have told me the reason for the
> differences in our systems is that your engineering programs are not
> regulated from university to university, so the quality of students is

Eesh!  Who *have* you been talking to?  Most engineering curricula in the United
States obtain accreditation from ABET (sorry, I don't remember what the acronym
stands for), which "regulates" the uniformity of programs at different colleges
and universities across the country.  Licensing boards and employers count
engineering degrees from programs that don't carry ABET accreditation as worth
much less.

Theoretically, the exams allow one to demonstrate competence in the field, thus
allowing the licensing boards to determine whether an engineer's designs will be
safe.  Practically, at least some of us think they also filter out some of the
less competent "wanna be" engineers out there; folks who managed somehow to
weasel their way into a degree, but who have never really understood what
they're doing.  It's an insurance policy.

Nigel