Stainless Design
Stainless Design
(OP)
Hi,
I have a building where the architect wants a cant. canopy with WTs flanges down and glass hanging from below. The longest dimension of the cant. WT is 13'. Using ASTM A992 carbon steel, a WT9x35.5 is at full bending stress and deflection limits. (Fy = 50 ksi). The only information I've found about using stainless for structural design is that type 304 is usually used. This yield strength (Fy) is only equal to 39 or 42ksi. This obviously changes my stress limits and would cut back on the length of the canopy, and not make our client happy. Is there another grade stainless steel that can be used and easily welded to a carbon steel HSS section? I am on the SSINA's website and find it very confusing and I feel no REAL information is provided. Let me know at your earliest convenience and please provide any references or suggested reading. Thanks for your help!
RC
I have a building where the architect wants a cant. canopy with WTs flanges down and glass hanging from below. The longest dimension of the cant. WT is 13'. Using ASTM A992 carbon steel, a WT9x35.5 is at full bending stress and deflection limits. (Fy = 50 ksi). The only information I've found about using stainless for structural design is that type 304 is usually used. This yield strength (Fy) is only equal to 39 or 42ksi. This obviously changes my stress limits and would cut back on the length of the canopy, and not make our client happy. Is there another grade stainless steel that can be used and easily welded to a carbon steel HSS section? I am on the SSINA's website and find it very confusing and I feel no REAL information is provided. Let me know at your earliest convenience and please provide any references or suggested reading. Thanks for your help!
RC
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke





RE: Stainless Design
I have seen some huge architectural jobs being done in these grades. Also both are much more corrosion resistant than 304. The LDX2101 is the lower cost of the two.
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Plymouth Tube
RE: Stainless Design
http://www.alleghenyludlum.com/
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Stainless Design
Thanks again guys.
Rick
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design
I don't know which codes to refer you to. 2003 or 2101 behaves just like high strength, low alloy steel, so I think the warning to not consider it like carbon steel does not apply here. Yield strength, modulus, etc.
Maybe some our more code-savvy memebrs will help us here.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Stainless Design
I am reading up on 2101 and I found this in one of the PDF documents on Outokumpu's website.
"However, it is important to point out that both austenitic and duplex stainless steel behave somewhat differently to carbon steel regarding structural design, particularly
regarding instability and local buckling. Design recommendations for stainless steel are available, such as Design Manual for Structural Stainless Steel, published by Euro Inox [5]."
Obviously the Euro code is useless to us. The SSINA is also useless for any design information.
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Stainless Design
I also found information on Bristish Stainless Steel Association's website which states the deflection of stainless steel beams increases at higher stresses.
See http://www.bssa.org.uk/topics.php?article=126 for information
Thanks again for the response.
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design
http://www.tmrstainless.com/index.html
They are a consulting firm with extensive experience in the applications of stainless steel. Catherine specializes in architectural applications.
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Plymouth Tube
RE: Stainless Design
https://www.asce.org/bookstore/book.cfm?book=4286
RE: Stainless Design
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design
So now the architect has changed his mind about the design and I have to design the item again, and I'm realizing that creating a moment connection at the base of the cantilevered upside down WT's is going to be a messy connection. I'm having the WT come back to a HSS12x8. This will be made of carbon steel (Fy=46ksi), and the custom WT out of stainless 304 (Fy=42ksi). I'm going to use 309 weld material to help prevent damage to the chemical make-up of either material.
While this connection will be "interior" I am worried water will still get into the area if snow drifts sit where the canopy extends from the facade. If water hits the welded area there is a concern of galvanic action and corrosion at the weld occurring. I know I could paint this after the weld is complete to help protect it, but is there some other permanent protection one can use?
Thanks guys.
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design
Stupid architects, must have stainless steel. Carbon isn't pretty enough painted.
RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke
RE: Stainless Design