Reference: Abbott, Richard. Analysis and Design of Composite and Metallic Flight Vehicle Structures 3 Edition, 2019.

15.2.8.1. Compression Buckling of Triangular Panels

This method is briefly covered in the excellent general reference:

 (NACA-TN-3781, 1957). There is little information given but it is worth including in this text.

General curve fits have been done for the curves in Figure 15.2.8‑1.

For the simply supported triangular panel the following expression can be used to calculate k:

And for the clamped edge condition the following expression can be used:

These approximations are available in this spreadsheet:

AA-SM-007-096 Mathematical Derivation of Triangular Plate Compression Buckling Coefficients

The values for k can be used in the classic buckling expression where b is the ‘base’ of the isosceles triangle:

There is no information available at this time on the plastic buckling of triangular panels in compression. It is advised to account for panel material plasticity, if F_cr    exceeds F_cy then limit F_cr  to F_cy . The buckling compression buckling analysis spreadsheet link is below:

AA-SM-007-052 Buckling of Flat Isotropic Plates – Compression Buckling of Triangular Panel

15.2.8.2. Shear Buckling of Triangular Panels

As before, this method is briefly covered in the excellent general reference  (NACA-TN-3781, 1957):

General curve fits have been done for the curves in Figure 15.2.8‑3:

For the simply supported triangular Panel the following expression can be used to calculate k:

And for the clamped edge condition the following expression can be used:

These approximations are available in this spreadsheet:

AA-SM-007-095 Mathematical Derivation of Triangular Plate Shear Buckling Coefficients

The values for k can be used in the classic buckling expression where b is the ‘base’ of the isosceles triangle.

This method is available in a spreadsheet at the link below:

AA-SM-007-051 Buckling of Flat Isotropic Plates – Shear Buckling of Triangular Panel