Cross sectional area of Column Web Stiffeners Calculator

Cross Sectional Plate Area Formula:

\[ A_{cs} = \frac{P_{bf} - F_{yc} \times t_{wc} \times (t_f + 5 \times K)}{F_{yst}} \]

Computed Force (P_bf):

Column Yield Stress (F_yc):

MPa

Column Web Thickness (t_wc):

Flange Thickness (t_f):

Distance Between Flange and Web (K):

Stiffener Yield Stress (F_yst):

MPa

Cross Sectional Plate Area (A_cs): m²

1. What is Cross Sectional Area of Column Web Stiffeners?

Definition: This calculator determines the required cross-sectional area of column web stiffeners to resist forces from moment connections.

Purpose: It helps structural engineers ensure proper stiffener design to prevent web crippling or yielding in steel columns.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ A_{cs} = \frac{P_{bf} - F_{yc} \times t_{wc} \times (t_f + 5 \times K)}{F_{yst}} \]

Where:

\( A_{cs} \) — Cross sectional plate area (m²)
\( P_{bf} \) — Computed force delivered by flange (kN)
\( F_{yc} \) — Column yield stress (MPa)
\( t_{wc} \) — Column web thickness (mm)
\( t_f \) — Flange thickness (mm)
\( K \) — Distance between flange and web (mm)
\( F_{yst} \) — Stiffener yield stress (MPa)

Explanation: The formula calculates the additional stiffener area needed beyond what the column web can resist alone.

3. Importance of Stiffener Area Calculation

Details: Proper stiffener design prevents local buckling, ensures force transfer, and maintains structural integrity at connections.

4. Using the Calculator

Tips: Enter all required parameters. Default values are provided for common steel properties. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for stiffener yield stress?
A: Most stiffeners use the same material as the column (F_yst = F_yc), typically 250-350 MPa for common structural steel.

Q2: When are web stiffeners required?
A: Stiffeners are needed when the computed force exceeds the web's capacity to resist local yielding or crippling.

Q3: What does the distance between flange and web represent?
A: This is the distance from the flange's outer face to the web toe of its fillet in rolled sections.

Q4: How is the computed force (P_bf) determined?
A: It's calculated based on connection forces, multiplied by 5/3 for gravity loads or 4/3 when including wind/earthquake.

Q5: What if the result is negative?
A: A negative result means the column web alone can resist the force, and stiffeners may not be required.