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Critical Buckling Stress when Slenderness Parameter is greater than 2.25 Calculator

Critical Buckling Stress Formula:

\[ F_{cr} = \frac{0.877 \times F_y}{\lambda_c} \]

Pa

1. What is Critical Buckling Stress?

Definition: Critical Buckling Stress is the maximum stress that can be taken by the section without failure. Any stress surpassing the critical stress makes the section (like a column) fail.

Purpose: This calculator determines the critical buckling stress for steel members when the slenderness parameter is greater than 2.25.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ F_{cr} = \frac{0.877 \times F_y}{\lambda_c} \]

Where:

  • \( F_{cr} \) — Critical Buckling Stress (Pa)
  • \( F_y \) — Yield Stress of Steel (Pa)
  • \( \lambda_c \) — Slenderness Parameter (must be > 2.25)

Explanation: The formula accounts for inelastic buckling behavior when the slenderness parameter exceeds 2.25.

3. Importance of Critical Buckling Stress

Details: Proper calculation ensures structural stability and prevents buckling failure in steel columns and compression members.

4. Using the Calculator

Tips: Enter the yield stress of steel in Pascals and slenderness parameter (must be ≥ 2.25). The slenderness parameter has a ±5% tolerance.

5. Frequently Asked Questions (FAQ)

Q1: When does this formula apply?
A: This formula applies specifically when the slenderness parameter (λc) is greater than 2.25, indicating inelastic buckling behavior.

Q2: What's a typical yield stress for structural steel?
A: Common values range from 250 MPa to 690 MPa (250,000,000 Pa to 690,000,000 Pa) depending on the steel grade.

Q3: Why is there a ±5% on slenderness parameter?
A: This accounts for practical variations in member geometry and material properties.

Q4: What if my slenderness parameter is less than 2.25?
A: A different formula applies for elastic buckling behavior (λc ≤ 2.25).

Q5: How is slenderness parameter calculated?
A: λc = (KL/r)√(Fy/(π²E)), where K is effective length factor, L is length, r is radius of gyration, and E is modulus of elasticity.

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