The buckling and ultimate strength behaviour of key structural components are critical factors to consider when designing offshore steel structures. To ensure the technical quality of these structures, plate buckling checks are performed according to various industry codes.

SDC Verifier includes two different plate buckling checks *(ABS plate buckling)* required by the American Bureau of Shipping (ABS):

- Guide for Buckling and Ultimate Stress Assessment for Offshore Structures, APRIL 2004 (Updated February 2012): (ABS 2004 ) (Help article on ABS 2004 Plate Buckling in SDC Verifier)
- Rules for Building and Classing Floating Product Installations, July 2014: (ABS 2014 ) (Help article on ABS 2014 Plate Buckling in SDC Verifier)

There are three small differences in calculation of **Ultimate Strength Limit**. **Buckling State Limit** is calculated completely the same.

Interaction coefficient between longitudinal and transverse stresses f, which is used in the calculation of **Ultimate Strength Limit**:

\((\frac{\sigma_{x\,max}}{\eta\sigma_{Ux}})^2-\varphi(\frac{\sigma_{x\,max}}{\eta\sigma_{Ux}})(\frac{\sigma_{y\,max}}{\eta\sigma_{Uy}})+(\frac{\sigma_{y\,max}}{\eta\sigma_{Uy}})^2+(\frac{\tau}{\eta\tau_{U}})^2\leq1\)

С_{x} coefficient, used in **longitudinal ultimate strength calculation**:

\(\sigma_{ux}=C_{x}*F_{y}\geq\sigma_{cx}\)

C_{Y} coefficient, used in **transverse ultimate strength calculation**:

\(\sigma_{uy}=C_{y}*F_{y}\geq\sigma_{cy}\)

ABS 2004 Plate Buckling | ABS 2014 Plate Buckling |

\(\varphi=1.0-\frac{\beta}{2}\) | \(\varphi=max(1.5-\frac{\beta}{2},0)\) |

\(C_{x}=2/\beta-1/\beta^2\;for\; \beta>1\) \(C_{x}=1.0\;for \;\beta\leq1\) | \(C_{x}=2.25/\beta-1.25/\beta^2\;for\; \beta\geq1.25\) \(C_{x}=1.0\;for\; \beta<1.25\) |

\(C_{y}=Cs/l+0.1(1-s/l)(1+1/\beta^2)^2\leq1.0\) | \(C_{y}=Cs/l+0.115(1-s/l)(1+1/\beta^2)^2\leq1.0\) |

SDC Verifier also has other standards for plate buckling checks:

- DNV CN30 Plate Buckling (1995)
- DNV RP-C201 Plate/Stiffener Buckling (2010)
- Eurocode3 Plate Buckling (EN 1993-1-5, 2006)

Plate Buckling checks are available in SDC Verifier Professional or in SDC Plate & Stiffener Buckling App