The section builder

Transcript

The section builder.

Start

The section builder is under Utilities in the wizard, as Section properties. It has no design code, and no LRFD or ASD, so its status reads Calculated. Describe the section four ways: a standard shape from the database, a parametric shape, a custom outline of points, or a section built up from parts.

A standard shape

Start from a standard shape, a W18X35. The area is 10.29 square inches, and the strong-axis moment of inertia is 509.8. Two values of the torsion constant appear, because they answer different questions: 0.5060 from finite elements on the true outline, fillets included, and 0.4625 on the thin-walled center line, the basis of published tables. Use the basis your equation assumes.

Built up from parts

Now add a cover plate. Choose Built up from parts, and enter the W18X35 and a plate, 8 inches by three-quarters of an inch, placed on the top flange.

The built-up section

The area is now 16.29 square inches, with the centroid 12.25 inches from the bottom, and a moment of inertia of 832.7. The section is no longer symmetric, so the section modulus has two values: 134.2 at the top, and 67.99 at the bottom.

The mesh check

The mesh check compares the finite element area with the exact one. Here, the difference is zero. Beyond half a percent, the mesh is not trusted, and the result is Not feasible.

What to do with the numbers

The properties do not flow into another calculation by themselves. Enter them where a type asks. The builder has no design code, so it checks neither the parts nor the welds that join them.

Report and sheet

Then print the report, with every check, its equations and its clauses. Print the drawing sheet on your own title block, at the size you choose. Or export the same sheet as a DXF for your CAD software.

Questions? Select Support in the app, or write to us at services@ilxstudio.com.