Column Stability

Compression strengths of columns can be predicted using theoretical elastic solutions for slender, symmetrical and centroidally-loaded columns. For short or eccentrically loaded columns, corrections need to be made using one of several methods:

• non-linear material behavior for compact sections
• semi-emperical method based on test data
• a curve fit (interaction) from Euler solution to cutoff (crippling, yield) such as Johnson-Euler

Note: Beam-column strength checks should be done, even on symmetrically loaded columns, with an assumed manufacturing tolerance such as L/400.

Column Properties Input

---

Units: English / Metric

---

Section Properties

Section Area - A:
Second Area Moment about x - I_x:
Second Area Moment about y - I_y:
Area Product Moment - I_xy:

Length and Fixity

Actual Column Length - L:
Fixity Coefficient - c:1.00 | End Load: Pinned - Pinned 4.00 | End Load: Mid-Pinned - Ends Pinned9.00 | End Load: Two-Pins Equal Space - Ends Pinned4.00 | End Load: Fixed - Fixed0.25 | End Load: Fixed - Free2.05 | End Load: Fixed - Pinned1.88 | Distributed Load: Pinned - Pinned3.55 | Distributed Load: Pinned - Fixed7.56 | Distributed Load: Fixed - Fixed.795 | Distributed Load: Fixed - Free5.32 | Distributed Load: Fixed - Pinned

or, Custom Column Fixity - c:

Material Properties

Compression Modulus - E_c:
Material Shape Factor - n:
Compression Yield - F_cy:
Section Crippling Stress - F_cc:

Applied Load

(optional) Applied Compression Load - P_c:

---

References

Metallic Materials Properties Development and Standardization (MMPDS), MMPDS-05. Federal Aviation Administration, April 2010.

Bruhn, E. F. (1973). Analysis and Design of Flight Vehicle Structures. Indianaponlis, IN.

Peery, D. J. (1950). Aircraft Structures. New York, NY.

Timoshenko, S. P. (1961). Theory of Elastic Stability. New York, NY.

Niu, M. C. (2001). Airframe Stress Analysis and Sizing. Hong Kong.

---

DISCLAIMER: The methods and calculation on aNOWysis.com are provided as means to educate the reader. There is no warranty, expessed or implied, as to the relevance or accuracy of the methods or calculations. All calculations should be checked by a qualified analyst for appropriateness and accuracy. We will not be held liable for any damages, injuries or deaths caused by using methods or calculations from this site.