D1.A.1 General Comments on Design as per AISC Unified Code
Both Allowable Stress Design and Load Resistance Factor Design methods are implemented in STAAD. The selection of the method can be done through the METHOD parameter explained in the parameter list. This Unified Code allows the designer to design the member as per LRFD as well as ASD method.
Design for Strength Using Load and Resistance Factor Design (LRFD)
Design according to the provisions for Load and Resistance Factor Design (LRFD) satisfies the requirements of the AISC 360 Unified Code Specification, when the design strength of each structural component equals or exceeds the required strength determined on the basis of the LRFD load combinations.
Design shall be performed in accordance with Equation B3-1 of the Code:
| Ru ≤ ϕRn |
| = | ||
| = | ||
| = | ||
| = |
Design for Strength Using Allowable Strength Design (ASD)
Design according to the provisions for Allowable Strength Design (ASD) satisfies the requirements of the AISC 360 Unified Code Specification when the allowable strength of each structural component equals or exceeds the required strength determined on the basis of the ASD load combinations.
Design shall be performed in accordance with Equation B3-2 of the Code:
| Ra ≤ Rn/Ω |
| = | ||
| = | ||
| = | ||
| = |