What it checks
The module designs a fillet weld group loaded off its centroid, supporting either a vertical line or a C-shape configuration. It applies the elastic vector method to resolve direct and torsional shear stresses at every segment of the weld group. The design method is selectable as either Allowable Strength Design (ASD) or Load and Resistance Factor Design (LRFD).
The calculation sequence begins by establishing the geometric properties of the weld group, including the centroid location and polar moment of inertia. It then computes the moment contributions from horizontal and vertical forces acting at their respective eccentricities. The module identifies the critical weld element where torsional stress reinforces direct shear, calculates the required weld size to satisfy the demand, and compares this against the provided weld size.
Inputs
- Geometry - Weld group configuration ("vertical_line" or "c_shape"), height of the weld group (in), and horizontal leg length for C-shape (in).
- Weld Properties - Fillet weld leg size (in) and electrode classification strength (ksi), such as 70 for E70XX or 80 for E80XX.
- Loads - Horizontal applied force (kips, + = right), vertical applied force (kips, + = downward shear), horizontal eccentricity from centroid (in, + = right), and vertical eccentricity from centroid (in, + = up).
- Method - Design method selection ("asd" or "lrfd").
What it reports
- Weld Properties - Total weld length (in) and total effective throat area (in²), calculated as 0.707 times width times length.
- Centroid Location - X-coordinate of the weld group centroid from the left reference edge (in).
- Inertia - Polar moment of inertia of the weld group about the centroid (in⁴) for unit throat.
- Critical Point - Location of the critical weld element relative to the centroid (in).
- Allowable Stress - Design strength on the effective throat (ksi), expressed as φ×F_nw for LRFD or F_nw/Ω for ASD.
- Weld Size Comparison - Provided weld size (in) and required weld size (in) to satisfy demand, unrounded.
- Standard Sizes - Provided and required weld sizes expressed in sixteenths, with the required size rounded up to the nearest 1/16.
- Minimum Size - Minimum fillet weld size per AISC Table J2.4, where the thicker plate controls.
Code references
The engine cites AISC 360-22 §J2.4 and AISC Manual 15th Ed. Part 8. The minimum fillet weld size is determined per AISC Table J2.4.
Limits
The horizontal leg length input is ignored for the vertical_line configuration. The module assumes the weld group is loaded off its centroid and does not account for other load paths or secondary effects. Results are engineering aids; the engineer of record is responsible for the design.