Missing property for ProfileTypeI

[jorge.bslu]

Hi

I am importing connection details from Revit 2023 and for Autodesk.AdvanceSteel.Profiles.ProfileTypeI the flange thickness location is missing (since H3 is the flange's slope, then, that property is needed).

Please also take a look at StructuralSectionGeneralI which is similar and it contains that property.

Regards

[RPTHOMAS108]

You would need a diagram of these section types to determine what is and isn't required. I don't know if advanced steel provides that somewhere.

However if the flange thickness is counted as a minimum then it would start at the top of the toe radius or likewise if it were a maximum then it would start at the bottom of root the radius (for bottom flange). So in those cases, you wouldn't need a thickness location since you have slope, start point and end point. The slope gives you the tangents of the fillets so you can establish their start and end angles and so their start and end points.

I don't know why they have flange thickness location it is probably to do with how these things have been defined by local standards for compliance of tolerances i.e. the flange needs to be measured at this point for compliance with rolling tolerances. 

The thing that always irritated me is that the standard sections don't encapsulate all that they could have i.e. what about the rolled ASB that could have been IParallelFlange if they had separated out the top and bottom flange widths. The nearest alternative is the welded section without the fillets. Then you have the distinction between 'I-shape Wide Flange' and 'I-shape parallel flange' which could have been avoided if the connection dimension sets were separated out into another class object. Also indicates that the distinction between parallel flange and tapered is pointless because if the slope is 0 then it is parallel.

I think class inheritance and not separating out the connection dimension sets into another class object is working against them here. Sometimes you just need to think in a non-abstract way and decide 'what is the minimum I need to define it'. However the horse has bolted as they say.

[jorge.bslu]

I would like to provide some context to my issue.

I am currently importing connections from Revit 2023 and I need to convert Revit objects into our own objects (including cross-sections).

In my case, I have a haunched beam-to-column connection where the haunch profile (family symbol) is the same than the parent beam. That cross-section/profile is an sloped flange shape.

I would expect to get from Revit API the same information (cross-section) for both elements, the beam and the haunch.

For the beam, I get the StructuralSectionGeneralI that includes the flange thickness location. But, for the haunch, it would be extremely useful to be able to process the family symbol as well as the beam, but as far as I can understand, that is not possible and I need to use the ProfileTypeI that comes from ASProfiles ... which is not nice for me as a Revit API user.

My concern is, why I can get full geometry information for the beam's cross-section but not for it's haunch (that theoretically comes from the same cross-section/family symbol)

The distance I am talking about depends on the Standard/Country, for example:

I have no control on how AS creates the ProfileTypeI from the Revit family.

Without that position, it is not possible to construct a cross-section with sloped flanges.

And it becomes worst for my importation when the haunch cross-section (family symbol) is not loaded in the current document.

Hope I have explained my self properly.

Fully appreciate your help !

Edit:

If I break the connection, this is what I get:

which is wrong because it is not an I-parallel flanges

And I am wondering why Family name (AS_EXT_BEAM_I) is not the same than the rafter's family name (M_S Shapes) 😞

[RPTHOMAS108]

The connection part comes from the advanced steel catalogue so not the same definition as the Revit structural shapes.

Yes it is difficult to construct the section but not impossible. The only thing that is ambiguous in the advanced steel is if the flange thickness is min or max. I don't think it can be average or a form of average because there isn't the horizontal position definition (even advanced steel would need that for an average). I would assume it is minimum and check that assumption in advanced steel: properties tab of the beam dialog.

The example properties in those links above are not great since they seem to be for the parallel flange but perhaps if you select an alternative section, you'll see more properties for items such as slope and can compare what flange thickness is matching against a real-world section product (internal value vs real world section value not the UI value).

You could also try searching in advanced steel forum I guess the topic of custom sections would have come up there.

[RPTHOMAS108]

I've done some further investigating of the advanced steel access data base found at:

C:\ProgramData\Autodesk\Advance\Data

And it appears that the flange thickness is measured at B/4 consistently for:

UK RSJs, European IPNs and US S-shapes.

The only one that was slightly out was comparing the access database value for a S12x50 (which appears to equate to S310x74) in the metric Revit family of that US section. The US S shape Revit family had rounded values, so I put the slight difference down to that. That is a 12" deep section of unit weight 50 pounds per foot (74 kg/m) apparently.

I've attached images of the advanced steel section database against the dims measured in the Revit family.

Anyway, not what I thought but logical perhaps.

Also unrelated: in the metric version it is 310x74 but this is a 308.4mm high section (1ft) and the actual parameter value is rounded to 305. So why they called it a S310x74 and not a S305x74 I do not know (that would have stood out more as being 1ft). It is why we have the 305 UB and the 610 UB in the UK (and the 10" section is the 254...although weight variations mean that only one 254 is actually 254 etc. ). The section width is similarly rounded which leads to the minor error noted above I suspect.

[jorge.bslu]

Thank you very much for your time and effort.

From your researches, I'd assume B/4 for every I-H sloped flange profile (which is fine for IPN's but not for US Shapes 🙂 )

Something similar happens with the T-profiles.

FYI: for channel  profiles (ProfileTypeU), if you break the connection, that distance has a fixed value  of 0.11ft for all of them, regardless the Standard/Country/Family.

Thanks one more time.