RAM Elements - Rectangular Bar Design

RE: RAM Elements - Rectangular Bar Design

Nik — Wed, 19 Jul 2023 19:30:10 GMT

Thanks Seth! I had overlooked the option.

RE: RAM Elements - Rectangular Bar Design

Seth Guthrie — Fri, 14 Jul 2023 13:44:42 GMT

I probably used the RectBar section template. For more see: Creating custom Sections, Materials etc. in RAM Elements [TN]

RE: RAM Elements - Rectangular Bar Design

Nik — Thu, 13 Jul 2023 22:54:05 GMT

May I please learn how you managed to model the rectangular bar section?

RE: RAM Elements - Rectangular Bar Design

Seth Guthrie — Fri, 21 Sep 2018 20:58:29 GMT

Yes, the expectation is that height is the larger dimension. I now remember this came up once before.

RE: RAM Elements - Rectangular Bar Design

Nulukkizdin — Fri, 21 Sep 2018 20:52:12 GMT

Sorry - the version I sent had the wrong member orientation (was oriented such that 1" was the depth). The original orientation (8" as the depth) still produces the same issue. These were all based on a section property with a height of 1" and a widthof 8".

That said, changing the section property such that the height is 8" and the width is 1" produces the correct result no matter what the orientation is in the model. It appears that for the slenderness checks it will use t = width and d = height no matter what the orientation of loading, correct? Either way, I think that does the trick - thanks!

RE: RAM Elements - Rectangular Bar Design

Seth Guthrie — Fri, 21 Sep 2018 20:43:53 GMT

Try inverting the section such that height is 8", and width is 1". You can rotate the members 90 degrees to keep the same analytical model.

RE: RAM Elements - Rectangular Bar Design

Nulukkizdin — Fri, 21 Sep 2018 20:41:55 GMT

Emailed it to you to check out - thanks for looking.

RE: RAM Elements - Rectangular Bar Design

Seth Guthrie — Fri, 21 Sep 2018 20:29:06 GMT

If you save your file (as a zip with custom data included) and send me that I can check it in v15 quickly.

RE: RAM Elements - Rectangular Bar Design

Nulukkizdin — Fri, 21 Sep 2018 20:23:53 GMT

Thanks for the response! When I put in your 12" tall , 1/4" thick plate I do actually see some results. When I had run my previous section, I was only seeing the yield failure mode checked (no LTB). I agree that your member should be checked for LTB (so that checks out), but technically my section meets the criteria meets the criteria in F11.2.

In my example Lb = 12", d = 8", t= 1", E = 29000 ksi, Fy = 36 ksi. Checking (L_b*d)/(t^2) I get a ratio of 96. Comparing this to 0.08*E/F_y (value of 64), I see that 96 is greater than 64 and thus I need to check LTB per (F11-2). When I go into my results, though, I'm only seeing the yield checks.

I've currently got version 14 installed, so I'll look into see if upgrading to 15 changes anything here quick.

RE: RAM Elements - Rectangular Bar Design

Seth Guthrie — Fri, 21 Sep 2018 20:04:07 GMT

Here is some steel design output from version 15.00.00.18 for AISC 360-10 LRFD design using a 12" tall, 1/4" thick plate with major-axis moment only.

Is this different from what you are getting? What version and design code are you using?