RE: PSI Model Joint Characteristics
David W Miller
Gus Tarnowski and Ferdi Baler are the 2 liaison engineers. I would think
they have the information you are seeking.
David
-----Original Message-----
From: Aluminum-Struct...@googlegroups.com
[mailto:Aluminum-Struct...@googlegroups.com] On Behalf Of Steve
Sincere
Sent: Tuesday, November 07, 2006 2:00 PM
To: Aluminum Structure Contractors
Subject: PSI Model Joint Characteristics
I have searched this site in hopes to find the definition of the joint
characteristics of the two PSI models and am coming up short. Are all the
joints assumed to be pinned (free to rotate about all axis) or fixed (not
free to rotate about all axis) or are there some that are pinned, some that
are fixed and some that are hinged (free to rotate about only one axis)?
This will play a significant role in the results (in particular the column
and beam joint). Are these models going to be solved with an initial set of
assumptions for these joint fixities or will those be set after physical
joint testing is done?
Thanks,
Steve Sincere
Brian Smith
gotten any response on it. It was not mentioned at the meeting that I
attended how the column and beam joint where connected. I saw them
looking at the AAF book at connections, But I dont know if thats how
the are going to be tested.
Tom Matson
Vern, please give a progress report.
Several companies have put money into the project and would like to
know what the current status is.
Tom
Tarnowski
There was some confusion and questions brought up at the last state AAF
meeting about publishing this PSI information on the public boards. We
need to get these questions answered first before we can release more
information. Initially the Palm Beach group that funded the project
wanted to make all the data free for all to see. Since then there has
been other groups that have financially contributed that may or may not
want this project so public.
Gus Tarnowski
Brian Smith
Chapter made any motion to with hold the results? I attend the meeting
on the shapes of the models and now I can't get any information on the
status. Both privately and publicly all of my attempts have failed. Why
are we fighting amongst ourselves? The AAF has over 300 members if you
divide that by the $100,000.00 it's as little as $33.00 per member. I
understand the cost expense but has it be shown to the state in this
fashion?
David W Miller
Try you calculator again ($333.33).
David Miller
-----Original Message-----
From: Aluminum-Struct...@googlegroups.com
[mailto:Aluminum-Struct...@googlegroups.com] On Behalf Of Brian
Smith
Sent: Wednesday, November 08, 2006 10:24 AM
To: Aluminum Structure Contractors
Brian Smith
Brian Smith
Chapter made any motion to with hold the results? I attend the meeting
on the shapes of the models and now I can't get any information on the
status. Both privately and publicly all of my attempts have failed. Why
are we fighting amongst ourselves? The AAF has over 300 members if you
Tarnowski
You or any other member of the Palm Beach Branch can contact me or Vern
directly to get any information on the PSI project.
Gus Tarnowski
g...@tarnowskieng.com
954-727-2027
David W Miller
We must all be sensitive to the political/economic consequences of
disseminating information. The AAF is a volunteer trade association and has
endeavored to provide leadership and improvement in the design and
construction of aluminum projects. In order to accomplish these long term
goals we have to keep the association together. If the AAF alienates a large
percentage of its membership, its industry position is weakened
considerably.
We simply have to be judicious about the dissemination of information which
may be inflammatory, believe me, I have made statements that have made a lot
of people mad. It's one thing for me to have personal opinions, its another
for a group representing the AAF to proclaim information that may be
perceived as detrimental to the businesses and livelihoods of many of its
members.
David Miller, Chairman
AAF Technical Committee
-----Original Message-----
From: Aluminum-Struct...@googlegroups.com
[mailto:Aluminum-Struct...@googlegroups.com] On Behalf Of Steve
Sincere
Sent: Thursday, November 09, 2006 9:58 AM
To: Aluminum Structure Contractors
Subject: Re: PSI Model Joint Characteristics
What would be the reasons for keeping this information private? I can think
of only two:
1) Someone wants to develop something proprietary and make everyone pay for
it or 2) there is a discovery that the current standard of care is
inadequate and that would be "too detrimental to the industry".
I also noted that the two designs being studied by PSI are vastly different
than "typical engineering" from even 6 months to a year ago.
I'm seeing a lot more bracing and heavier secondary members. I've even seen
an extrusion size called out that Town and Country doesn't stock.
This is not a study of "the good old engineering that always worked", this
is a study of something else.
Does anyone else see the irony in this?
Steve Sincere
Vernon McLean
David has eloquently stated the political dilemma we have encountered. I
personally believe that the process and results should be completely open to
all. Hiding the truth does not make it go away. It will only serve to
perpetuate engineering and construction of non-code compliant enclosures.
Another hurricane may decimate our industry if everyone does not provide
customers with what they are entitled to. The media is not going to write
articles about the enclosures that survived. They are going to ripe us apart
with the failures.
Another benefit to an open process is that it affords everyone an
opportunity to express their opinion on the methodology we are using. So far
we haven't received very much constructive opinion for those not directly
involved with the project. Steve and David, I would especially like yours.
Steve, there isn't a conspiracy. We aren't developing anything proprietary
and when we encounter inadequacies we develop solutions. That is why you
haven't seen some of the extrusions we are testing.
All of the designs will eventually be freely available to distributors and
manufactures, but we may show preferential treatment to those that have
helped finance the project. I personally don't believe that the suppliers
should get a free ride.
Steve, you deserve an answer to your question on joint properties. So here
it is and please provide feedback.
The project is split into 3 phases. In the first phase, we are comparing
analytical (generally misnamed 2D) modeling to FEA. Because the industry
generally models all of the joints, with the exception of splices, as
pinned, we are also. This is only for the purpose of comparison.
In the second phase, physical testing will be performed to determine actual
joint properties. The joints will be loaded and deformation measured. The
models will be reevaluated in the third phase with realistic parameters for
the joints.
Steve, I would have preferred if the State had taken the initiative, but
they didn't and time is running out. We needed answers to remain in business
and no one was offering any with the exception of you, with your proprietary
system. By now, I'm confident that you have discovered that there isn't much
interest from other contractors in buying from a competitor. Your system may
have been easier to sell if your partners weren't also in business against
us.
Thus far, the State has done nothing and has had no involvement. That is
their mistake. They should have taken a leadership position, but they
didn't. We could not wait any longer.
Vern
David W Miller
It's not the best possible scenario, nor is it the worst possible scenario.
The state association's leadership has been advised and is working with the
chapter.
David
-----Original Message-----
From: Aluminum-Struct...@googlegroups.com
[mailto:Aluminum-Struct...@googlegroups.com] On Behalf Of Steve
Sincere
Sent: Thursday, November 09, 2006 11:13 AM
To: Aluminum Structure Contractors
Subject: Re: PSI Model Joint Characteristics
I understand the politics about keeping the association placated. What I
find ironic is that we have a rouge team independently developing their own
methodology and extrusions apparantly without input from the
association...again. This "new" effort seems to be doing a lot to mimic the
"old" effort. What is to be done with these "new" results? Who will
determine their usefullness or lack thereof? How many independent efforts
have to take place before the state level AAF gets involved? I am hoping
that the state level AAF is at least monitoring these developments and at
some point in the future will be willing to issue a statement on all these
efforts.
Steve Sincere
adam
> Vern,
>
> Thanks for your response. I was sure that the facilitators of this
> project intended to make all findings public and that it was not up to
> the state AAF to decide if this information was to be published or not.
>
> That said, there are surely a lot of interested parties besides Brian
> Smith and I that would like to know the status of any findings. I am
> not asking you to give away any design secrets that you developed and I
> don't think that anyone else is. We are intested in knowing how far you
> have gotten and what problems may have surfaced.
>
> As for your process, I have kept out of it since not too many people
> want to hear what I have to say, for one reason or another. However,
> I'll give you my thoughts now.
>
> First, the term analytical modeling can be used for anything that uses
> one or more mathematical equations to determine the behavior of
> something. Calculating how fast an object is moving a given period of
> time after it is dropped can be considered analytical modeling.
> However, in that instance there is only one degree of freedom or motion
> involved (height to point of release) and thus it is a 1D model. If any
> analytical modeling is considering stiffness and/or motion in only two
> directions, by definition it is 2D modeling. I have yet to see any
> "classical" enclosure modeling that considers stiffness and/or motion
> in anything other than vertical and horizontal...there has been no
> consideration of lateral effects in addition to vertical and
> horizontal. But all this is semantics.
>
> Phase I is exactly as it should be. However, these model are quite a
> departure from the engineering that everyone said was just fine mere
> months ago. Please comment on this.
>
> Phase 2 is as would be expected if one were to model the joints with
> torsional stiffness. That is to say that no joint is a perfect hinge
> (since there is always some level of friction) nor is it perfectly
> rigid (due to the flexibility of the connecting hardware...unless, of
> course, it is a weld). I believe that what you will find is that some
> joints are so soft (the torsional stiffness is so small) that they tend
> to act like a hinge and some are so stiff that they act rigid. This
> will play a significant part in joints between columns and roof members
> since this is where bending moments tend to be transferred. However, in
> braces the bulk of the problems tend to be in axial load, compression
> in particular. Hinge action will have little effect on that.
>
> Phase 3 will result in a model that is more accurate than phase 1. But
> I think that you will look at the joint testing results and discover
> that the assumption of "all pinned" is obviously flawed. I think that
> you can determine the fixity of most joints just by looking at them. I
> think that a model using logical determination of fixity will give
> results nearly identical to those with torsional stiffnesses in the
> joints when all is said and done. But the study is an interesting
> intellectual exercise.
>
> I understand your point of view on buying from a competetor. So,
> hypothetically speaking, what if Jude was just another engineer? Would
> using "his" system be more palitable? Even if it shows that a lot more
> metal and more substantial joints must be used? Even if it demonstrates
> that "classical" methodology is flawed? I think we know the answer to
> that. What about buying metal from a competetor? Several new extrusions
> have come to market recently that have obvious ties to contractors.
> Should those extrusions be shunned as well? What about the developments
> your team is making? Doesn't "eventually be freely available to
> distributors and manufactures, but we may show preferential treatment
> advantage"? And how long is "eventually"?
>
> So, here are my points:
>
> I agree with you, if information shows that the classical methodology
> is flawed, it should be published regardless of public or political
> opinion. The industry needs the truth, not the perpetuation of lies.
>
> I see nothing wrong with your study. The overall process makes logical
> sense. However, it is not investigating "typical engineering" as
> defined by designs from 6 months ago.
>
> If someone comes to market with a product, and there is demand for it,
> should not that person benefit? If there is no demand, then the product
> goes away. If someone squashes efforts to promote that product and then
> develops their own and brings it to market and controls
> distribution...well that's the definition of monopoly.
>
> Be careful how you choose your words.
>
> Steve Sincere
Steve and Dave
First I want to respond to David. If you think that we can not keep
information from the industry/public or building departments because it
may have consequesces your wrong. If you do not realize that engineers
that have a finacal interest in seeing the guide dismantled are not
going to challenge every thing in chapter one than there is something
wrong with you. If you think contractors and engineers that have spent
thousands of dollars on software and extrusions to monopolise the
industry are going to go away you are wrong. When are you going to get
involved with psi to back up the information in the manual. You should
be the one helping us get backing from ythe State for this testing.
Steve
That is a really long post. I am not an engineer so I won't even try
to respond to it.. I promoted PSI because as you know I still feel 70%
of the enclosures are the same and do not need 3d finite analysis for
every enclosure. Myself and Vern have no other motive than to get the
right formulas and extrusions needed to meet the building code that
goes into effect Dec. 8
We have the many suppliers backing us finacialy and only the State AAF
is giving us flack. But I am hopeful they will be on board. Vern and
myself have donated more time for free that I care to think
about.(Vernway more than me) This all started after we went to our
first engineers meeting and saw all the engineers hanging on every word
Mr. Kissel said. And he told them they were all wrong and you needed 3d
for every enclosure. Then it gets better our President starts an
engineers firm to offer what else but 3d. That is why I promoted PSI to
get everyone on a level playing field. Please never suggest that we had
any other motives.
Adam
adam
Thanks for your support I will let every one know and I think they
would love to compare notes
Adam