What it checks
The module designs solid freestanding signs and walls, rooftop equipment, and other structures. It applies the force equation F = qz G Cf As, utilizing aspect-ratio and clearance-ratio force coefficients to determine wind loads. The design method follows the provisions for components and cladding pressures.
The sequence of checks begins with the calculation of velocity pressure, qz, based on wind speed and exposure conditions. The module then applies the gust factor and force coefficients to derive the total wind force. Results include specific guidance notes for torsion in narrow signs and resultant offset adjustments for walls on grade.
Inputs
- Wind - Basic wind speed (mph), exposure category (B, C, or D), and ground elevation (ft).
- Geometry - Sign or wall height (ft), width (ft), and clearance height (ft).
- Structure - Support type (single cantilever pole or two-pole frame) and aspect ratio parameters.
- Site - Terrain exposure parameters and effective height adjustments for low-rise conditions.
What it reports
- Velocity Pressure - The calculated qz value (psf) compared against the wind speed and exposure coefficients.
- Wind Force - The total force F (lb) derived from qz, G, Cf, and As, compared against structural capacity.
- Force Coefficient - The Cf value based on aspect and clearance ratios, compared against ASCE 7-22 tables.
- Case Guidance - A note indicating Case B torsion for narrow signs or Case C default conditions.
- Resultant Offset - A note specifying the +0.05h resultant offset for walls on grade with s/h = 1.
- Exposure Coefficient - The Kz or Kh value calculated from height and exposure, compared against Table 26.10-1 limits.
Code references
The engine cites ASCE 7-22 Ch.29 — Eq. 29.3-1 signs / freestanding walls. It also references ASCE 7-22 Table 26.10-1 for velocity pressure exposure coefficients and Table 26.11-1 for exposure constants. The module utilizes the general wind pressure equation from ASCE 7-22 Eq. 26.10-1 to determine the base pressure values.
Limits
The module assumes the structure is a solid freestanding sign or wall supported by a single cantilever pole or a two-pole frame. It does not address perforated signs or structures that do not meet the solid definition. The calculation ignores internal pressure effects specific to enclosed buildings, as the module is designed for freestanding components. Results are engineering aids; the engineer of record is responsible for the design.