# AISC ASD 1989

AISC ASD 1989 - an American national standard "Specification for Structural Steel Buildings" Allowable Stress Design and Plastic Design, released in June 1, 1989.

This Standard implements checks for the design of members for tension, compression, bending, shear and combined. Checks are performed for I-beams, Channels, Tee, Circular and Rectangular tubes, Circular and rectangular bars.To add AISC ASD 89 standard execute

– from the main menu. Alternatively use the context menu:To see what elements are not verified for all checks or bending checks according to AISC ASD 1989 press

.Press to set

(rolled or built-up).Lateral-torsional buckling modification factor (Cb) can be calculated based on moment diagram of beam member or defined manually. By default user defined option is used and Cb is set to 1 (conservative):

Where *M1* is the smaller and *M2* the larger bending moment at the ends of
the unbraced length, taken about the strong axis of the member.

Press to set Cb manually.

By default clear distance between transverse stiffeners are set to torsional member length. (It means there are no transverse stiffeners). Stiffener distance is used to calculate allowable shear stress:

According to the calculation procedure, Beam Length for Y and Z direction is required. Data from Beam Member Finders is used automatically:

If beam members are not recognized press .

The formulas of AISC ASD 89 standard use Yield Stress from materials. It is important to set this value for each material.

If count > 0 then press to edit Yield Stress:

It is possible to take into account second order effects (see explanation in AISC ASD 89 , Appendix 8):

When all settings are defined, press

to create standard.The standard contains 13 checks: 1 - beam characteristics, 2-7 - calculation dimensions and factors for shapes, 8-10 - classification, axial and bending strength checks, 11 - Tension and Compression check, 12 - Shear Check, 13 - Bending Check, 14 - Geometry checks, 15 - utilization factors for shear and combined axial with bending checks.

To verify the model create a table for Overall Check:

All Checks have Utilization Factor parameter = (Force, Moment, etc.) / Design Strength. It should be below one (<1) then the check passes.

The value 12345678 is used when the calculations cannot be performed due to geometrical limitations or calculations are out of scope.