How to add custom shapes

[StuMcGimly]

I would like to use a double channel shape use as heavy cross bracing. Since it doesn't match the hot rolled types I modelled the shape in soildworks and copied the section properties to a general, arbitrary shape type.

I then had to add a A36 material to the general material DB and appied it to the section set using the double channel shape I created.

No results are found for the members I have made double angle and I am a bit stumped on how to get this to work.

Does anyone know how to get this to work?

 

[steve1]

The following is from the RISA Help menu:

Arbitrary Shapes are a special, catch-all shape. This arbitrary shape type is provided so that any shape can be added to the shape database. By entering the "d" values (the distances to the extreme fibers), you'll give enough information to calculate stresses at the extreme fibers of any shape.

AISC code checks are not calculated for arbitrary shapes since their place in the specification is unknown. Everything else will be calculated for them (forces, deflections, stresses). The max thickness (Max t) value for the cross section is used to determine the pure torsional shear stress for the shape.

Refer to Member Shear Deformations and Member Shear Stresses for more information on the shear area factors (As-zz Def, As-yy Def, .As-zz Stress, & As-yy Stress) shown in the figure below.