Table of Contents
Optimizing steel member sizes is essential for effectent structural design. Thee American Institute of Steel Construction (AISC) provides guidelines and code- based metods to determinate approvate member sizes. This article complicains thae methodology and provides worked examples to ilustrate strate process.
Understanding AISC Code Requirements
Te AISC Specification outlines the minimum requirements for steel member design, including acidith, stability, and serviceability. It consisisizes thee importance of selecting member sizes that meet these criteria while minimizing material use.
Methodology for Member Size Optimization
Te proceses involves calculating thee applied section condities based on on dead conditions and then selecting thee smallett section that condifies these requirements. Key steps include:
- Určete faktored loads and moments.
- Calculate thee applid section modulus and area.
- Vybrat kandidate steel sections from the AISC tables.
- Ověřujte si, že je section meets acidoth and stability criteria.
Worked Exampe
Konsider a simptomly supported beam with a span of 6 meters subjected to a uniform hebd of 20 kN / m. Thegoal is to select an applicate W- shape steel section.
First, calculate thee maximum bending moment:
M = (wL ^ 2) / 8 = (20 × 6 ^ 2) / 8 = 90 kNm
Next, determine the applid section modulas:
S = M / ∞ _ allow = 90,000 Nm / 250 Mpa = 360 × 10 ^ -6 m ^ 3
From AISC tables, select a W- shape with a section modulus greater than 360 × 10 ^ -6 m ^ 3. For example, W250 × 33 has Sx К 385 × 10 ^ -6 m ^ 3, approfying thee condiment.
Ověřujte, že se section 's capacity for axial and shear names as needded. Thee selected section provides a safe and equilent solution for thee beam design.