The slenderness in steel design of Code AISC 360-16

RE: The slenderness in steel design of Code AISC 360-16

Ko, JungMo — Mon, 02 Aug 2021 10:11:32 GMT

The original post is only regarding slenderness check.

So I replied the slenderness check will be done by longer length.

The slenderness check is completed and it is not related directly with compression capacity check.

Ofcourse the Lz and Ly will be used calculate the compression capacity.

However now you mentioned about compression capacity, The Compression capacity for each axis will be calculated with each Lz and Ly separately.
But the minimum capacity will be used for design results. Becasue it will be the governing limit state.

Design is not over design, it is exact design.

If you look into the design result with track 2, then you would understand what I said

RE: The slenderness in steel design of Code AISC 360-16

Zhengzhong Zuo — Mon, 02 Aug 2021 08:34:37 GMT

The slenderness ratio is regarding two perpendicular direction of section, Lz/rz, and LY/ry. The compression capacity is controlled by the minimum slenderness ratio. If maximum Ly and Lz to be used to check both direction, the design results are to be over-design. The OWNER shall be challenging the structural engineer.

RE: The slenderness in steel design of Code AISC 360-16

Ko, JungMo — Mon, 02 Aug 2021 08:27:55 GMT

Slenderness check is for Critical case, regardless what user specify LZ or LY.

If Lz is bigger than Ly than Slenderness check will performed using Lz.

If Ly is bigger than Lz than Slenderness check will performed using Ly.

RE: The slenderness in steel design of Code AISC 360-16

Zhengzhong Zuo — Mon, 02 Aug 2021 01:14:45 GMT

Thanks for you response.

The question of mine is that to calculate the slenderness regarding weak axis of member, the calculated length of weak axis is not taken as LY which is not defined in design parameter.

This is regarding under compression, not tension.

In current version of STAAD.Pro, if a member was supported with some infill beams and or some horizontal braces in weak axis, and the LZ is defined in design parameter, the software is taken LZ to calculate slenderness in weak axis. Actually, the LY shall be taken as physical length.

I don't know the description of question is clear or not.

RE: The slenderness in steel design of Code AISC 360-16

Modestas — Fri, 30 Jul 2021 07:14:20 GMT

An explanation to your issue can be found in the Bentley Communities forum discussion: https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/194660/aisc-360-2010-vs-aisc-360-2016/577932#577932