Plate buckling strength is an important aspect in offshore steel constructions design. Each plate should be checked as it influences on the strength and stability of the whole construction. We should pay particular attention to the calculation of the ship’s hull, which consists of numerous longitudinal and transverse panels.
SDC Verifier implements plate buckling check in ANSYS, Femap or Simcenter 3D according to the following Standards:
- DNV CN30/1995 (Buckling Strength Analysis), DNV RP-C201 2010 (Buckling Strength of Plated Structures)
- American Bureau of Shipping (ABS) Steel Vessel Rules 2006, ABS 2014 (Buckling and Ultimate Strength Assessment for Offshore Structures)
Theoretic background of the plate buckling
SDC Verifier CEO Wouter van den Bos created educational video on buckling fundamentals:
The most complicated task in performing plate buckling check on a general Finite Element Analysis model is to define a big amount of plates and dimensions of these plates to be verified.
Manual recognition of all the plates is a time-consuming operation, but we have an automatic model FEA recognition tools that can ease the process. SDC Verifier bring to user the Stiffened Panel Finder — tool to automatically recognize sections, panels, plates, stiffeners and girders, and dimensions of these structural members.
The recognition of plates, stiffeners and girders is based on mesh connectivity and can be performed on any structure which is built with either plate or shell elements.
SDC Verifier recognizes automatically all the structural members, and mesh independently. This brings to user an opportunity to have a model with fine mesh for precise results of the general finite element analysis and use the same model for calculation ABS plate buckling or DNV plate buckling checks.
Plate Buckling calculation approach
Plate buckling check results are Ultimate Strength Limit and Buckling State Limit. These results depend on plate stresses and plate dimensions (length, width and thickness).
Various options for stresses checked:
- Element Stress: MidPlane (no bending) or Average;
- Use Plate Average Stress – stress is averaged on plate using elements area. SDC Verifier performs calculation on every element but with averaged plate stresses.
For Plate Average Stress it’s also possible to use an Average Shear Stress or conservative method of taking Absolute Shear.
Note: Plate buckling checks require verifying stresses into the plate direction (direction of the longest plate edge). In SDC Verifier conversion of stresses is done automatically. For average option stresses are firstly averaged and then translated.
Results of buckling check in SDC Verifier
SDC Verifier presents results of plate buckling check in a convenient and user-friendly way:
- In form of tables. Possible to present results over selections or over load combinations;
- In form of plots. For any view and selection.
Plate Buckling Checks According to DNV 2010 (Buckling Strength of Plated Structures) Webinar
To find out more and see the detailed calculation procedure please download SDC Verifier.