Section Library Reference¶

Each member also references a reusable section definition. Area uses in2 or mm2; Iy, Iz, and J use in4 or mm4 in the member local axes. Iz governs in-plane bending for the current XY frame model. Custom properties are entered directly; definition names alone do not perform a section-catalog lookup. The initial default uses W18x35 properties but is classified as custom, like older saved definitions. Split segments inherit their original section.

The offline library contains 15 doubly symmetric wide-flange, square, rectangular, and round HSS sections, not a complete catalog. Its numerical properties come from the August 2023 AISC Shapes Database v16.0, consistent with the 16th Edition Manual, first printing. The source workbook was retrieved from this public mirror because the official download returned HTTP 403. Its SHA-256 is 82d0ceb96a0d938ae1a6bd9637cb10a1e269225b5d668dce5b0bdc8d86013496. Only designation, A/Iy/Ix/J and the 15 shapes' dimensional numerical facts are bundled, not the workbook. The dimension excerpt and worksheet row references are preserved in tests/fixtures/aisc_v16_dimensions.json. The mirror revision used for these checks is f32abe5b162cb66aa590e3c2b107b7a726124713; its workbook hash matches the original library source above. Values use U.S. customary columns C, F, AQ, AM, AX; metric previews convert these values rather than using the workbook's separately rounded metric columns. Strong-axis bending maps catalog Ix to PyNite Iz and catalog Iy to PyNite Iy. Weak-axis bending swaps those inertias; A and torsional J stay unchanged. HSS design properties are taken directly from the database, not recalculated from nominal wall thickness. Imported catalog properties and orientation are validated on reopen; modified values must be classified as custom. Materials remain a separate assignment, and imports do not change them. This is a stiffness library, not a strength, buckling, or code-compliance check. Verify suitability and section properties independently for engineering use.

The chooser includes a resizable dimensioned section sketch alongside the numerical property table. Wide flanges show d (depth), bf (flange width), tw (web thickness) and tf (flange thickness). Box HSS shows Ht/B; round HSS shows OD. Both HSS families show nominal and design wall thickness separately, and draw the design wall. Source US columns are G/L/Q/T for wide flanges, I/N/W/X for box HSS, and K/W/X for round HSS. Dimensions convert to the current project's length units. They use the published actual dimensions, not values inferred from the section name: W18X35 depth is 17.7 in, while HSS6.625X0.280 has published OD 6.63 in. Select Weak axis to rotate the sketch 90 degrees within the fixed local y/z axes, matching the table's Iy/Iz swap. Empty searches clear both previews.

The outline is idealized: fillets and HSS corner radii are omitted. It does not recalculate A/I/J, supply stress recovery or perform code design. Browsing and rotating do not edit the project; Add to Project uses the existing validated catalog-property import and provenance workflow.

Source: GUIDE.md. This manual follows the current repository; the published rc1 wheel has a smaller feature set.