Need a book? Engineering books recommendations...
RE: Side Plate Systems - Eureka Moment[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: "'seaint(--nospam--at)seaint.org'" <seaint(--nospam--at)seaint.org>
- Subject: RE: Side Plate Systems - Eureka Moment
- From: "Carter, Charlie" <carter(--nospam--at)aiscmail.com>
- Date: Fri, 30 Nov 2001 20:20:37 -0600
Title: RE: Side Plate Systems - Eureka Moment
>>Just for the record, the side-plate and the
>>beam slot connections were both originally
>>proposed to AISC along with the dog-bone.
>>AISC only had money to develop one of them,
>>and chose the dog-bone. At least this is
>>what I was told by both developers.
Not really. AISC was not holding the big money bags in all this. SAC was, thanks to the check-writing of FEMA.
Very early in Phase I of the SAC Steel Project, one of the two proprietary moment connection vendors-to-be was participating as a hopeful researcher seeking some of the FEMA funding that SAC had to dole out. In those days, the big slots were being proposed to be placed in the column web behind the beam flange welds, not in the beam web as they are today. As I understand it, there were technical and commercial reasons why that vendor-to-be did not receive any money from SAC. The other vendor had already decided to go into business while SAC was still forming their plans and did not pursue any financial support from SAC, at least as far as I know.
At about the same time, AISC put seed money into seismic moment connection research, first for coverplates and subsequently for dogbones. Though comparatively modest, this funding was enough to get both projects started. Then, SAC spent much more of its FEMA millions on those (especially dogbones which have been fairly extensively tested to date) as well as other connection details that are included in FEMA 350 and its companion documents. These include end plates, free flanges, bolted flange plates, flange tees, improved directly welded flanges, weld overlays, etc. Proprietary solutions are acknowledged, but otherwise not addressed in FEMA 350.
As I said before, there are a LOT of options for designers to pick from, both free and proprietary. And that is the good thing!
Incidentally, the dogbone was first developed by European researchers, including some funded by TradeARBED, who patented the dogbone. HOWEVER, they released all claims of patent so that the connection could be freely used for the greater good of the public, the design community and the steel construction industry.
>>Both companies invested personal money to develop
>>these systems. I think it only fair they
>>receive some reward.
I mean no disrespect to anyone who has invested of themselves in what are now proprietary connection details. In fact, I was impressed back when I met with Messrs. Meyers, Nelson, and Houghton (the original SidePlate folks). They came all the way to Chicago to show us their work, and seemed to me to have a very well thought out design procedure and broadly useful connection detail. I believe they are not just marketing a connection detail, but rather, engineering services. The latter is worth a fee in my mind.
I've also had similar meetings with the slotted beam folks. I was impressed on that occasion by Ralph Richard's finite element studies that showed the effects of the long slots. I did have some technical disagreements, though, with the assessment of limit states observed in the testing and what could be guaranteed to occur or not occur in a real building connection. Again, the vendor will provide engineering services in conjunction with the connection and, I believe, should be paid when hired.
However, I too have a very difficult time understanding how a fabricated assembly of plates, cuts, holes, welds, and/or fittings can be patented. Plus, I have to think a search of a few engineer's drawing files, project notes, doodle pads and cocktail napkin collection might turn up a lot of prior art that looks a bit like some things that have now come to be patented.
I'm not saying fittings and such can't be patented. I'm just commenting that it surprised me that these apparently could be. As a result, I looked into the process and learned that the U.S. Patent and Trademark Office is so swamped that they tend to treat all patent requests as "defensible until proven indefensible by challenge in court". That is, they assume that if they grant a patent and it is not patentable or invalidated by prior art, someone will challenge that patent and defeat it.
To me, the best example of how to approach and use patented devices in steel construction is the shear stud connector. Nelson doesn't try to make money off that patent. Rather, they just sell the studs and the equipment to install them.
I suppose I (and we all) shouldn't care, though, since all these systems, free or patented, give viable and competitive solutions for steel moment frames. Just make good cost comparisons between them (consult fabricators!), count the real costs, and you'll be doing your clients a service.
- Re: Side Plate Systems - Eureka Moment
- From: Henry Gallart
- Re: Side Plate Systems - Eureka Moment
- Prev by Subject: RE: Side Plate Systems - Eureka Moment
- Next by Subject: Re: Side Plate Systems - Eureka Moment
- Previous by thread: RE: Side Plate Systems - Eureka Moment
- Next by thread: Re: Side Plate Systems - Eureka Moment