1. What is Square Tube Buckling?

The Euler buckling formula calculates the critical axial load at which a slender column will buckle. For square tubes, this depends on the material properties and geometric dimensions of the tube.

2. How Does the Calculator Work?

The calculator uses the Euler buckling formula:

Where:

• \( P_{cr} \) — Critical buckling load (N)
• \( E \) — Modulus of elasticity (Pa)
• \( I \) — Moment of inertia (m⁴)
• \( K \) — Effective length factor (dimensionless)
• \( L \) — Length of column (m)

Explanation: The equation shows that buckling load is directly proportional to material stiffness (E) and cross-section stiffness (I), and inversely proportional to the square of the effective length (KL).

3. Importance of Buckling Calculation

Details: Buckling is a critical failure mode for slender compression members. Accurate calculation helps ensure structural stability and safety in engineering designs.

4. Using the Calculator

Tips: Enter all values in consistent units (Pa for E, m⁴ for I, meters for L). Typical K values: 1.0 for pinned-pinned, 0.5 for fixed-fixed, 0.7 for fixed-pinned.

5. Frequently Asked Questions (FAQ)

Q1: What is the effective length factor K?
A: K accounts for end support conditions. It's the ratio of the effective buckling length to the actual length of the column.

Q2: How do I find the moment of inertia for a square tube?
A: For a square tube with outer dimension b and thickness t: \( I = \frac{b^4 - (b-2t)^4}{12} \)

Q3: What are typical E values?
A: Steel: ~200 GPa, Aluminum: ~69 GPa, Wood: ~10 GPa (varies by species and grade).

Q4: When is Euler buckling applicable?
A: For long, slender columns where buckling occurs before material yielding (slenderness ratio > critical value).

Q5: What safety factors should be used?
A: Typical safety factors range from 1.5 to 3.0 depending on application and design codes.