Stiffener Yield Stress given Cross Sectional Area of Column Web Stiffeners Calculator

Stiffener Yield Stress Formula:

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

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):

Cross Sectional Plate Area (A_cs):

m²

Stiffener Yield Stress (F_yst):

1. What is Stiffener Yield Stress?

Definition: Stiffener Yield Stress is the minimum stress at which a stiffener will undergo permanent deformation or plastic flow without a significant increase in load.

Purpose: It helps structural engineers determine the required strength of web stiffeners in steel columns to prevent local buckling.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( F_{yst} \) — Stiffener Yield Stress (MPa)
\( P_{bf} \) — Computed Force delivered by the 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)
\( A_{cs} \) — Cross Sectional Plate Area (m²)

Explanation: The formula calculates the required yield stress of stiffeners based on the forces acting on the column web and the geometric properties of the column.

3. Importance of Stiffener Yield Stress Calculation

Details: Proper calculation ensures structural integrity, prevents local buckling of column webs, and helps in designing appropriate stiffeners for moment connections.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Default values are provided for reference. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for stiffener yield stress?
A: Typically between 250-350 MPa for structural steel stiffeners, but depends on material grade.

Q2: How is the computed force (P_bf) determined?
A: It's calculated from the flange force in moment connections, considering load factors (5/3 for dead/live loads, 4/3 when including wind/earthquake).

Q3: What if my calculated F_yst is negative?
A: A negative value indicates the column web alone is sufficient to resist the forces, and stiffeners may not be required.

Q4: How does distance between flange and web (K) affect the calculation?
A: Larger K values increase the moment arm, requiring higher stiffener capacity to resist the forces.

Q5: Can this calculator be used for both rolled and built-up sections?
A: Yes, but ensure proper measurement of K (distance between flange and web) which differs for rolled and built-up sections.