Plate Stability

Compute the critical buckling load of a plate subjected to uniaxial or biaxial in-plane compression.

To perform a stability analysis of a laminate composite plate, select the Stability tab from the Plate Analysis window. Once the Laminate and Plate Geometry tabs have been defined, complete the following four steps in the Stability tab (see image below).

1. Specify Loading and Boundary Conditions - The Loading and Boundary Conditions drop-down menu contains three different combinations of transverse loading and boundary conditions that can be selected:
   • Uniaxial Compression - SSSS denotes a uniaxial compressive load in the global X direction, applied to a plate that is simply supported on all four edges (see part a of the image below).
   • Uniaxial Compression - SSCC denotes a uniaxial compressive load in the global X direction, applied to a plate that is simply supported across the width and clamped along the length (see part b of the image below).
   • Bi-axial Compression - SSSS denotes a bi-axial compressive load in the global X and global Y directions, applied to a plate that is simply supported on all four edges (see part c of the image below).
2. Specify Number of Modes to use in the Double Sine Series Solution - The m _max and n _max boxes are used to specify the number of sine modes used in the global X and global Y directions, respectively, in representing the transverse deflection (see equations in Plate Module section). As the integer values of m_max and n_max are increased, the transverse deflection is represented more accurately. In most cases, m_max = n_max = 10 provides a reasonably accurate solution. However, the solution is obtained very efficiently, so even m_max = n_max = 100 returns a solution rapidly.
3. Specify the Ratio of Transverse Compression to Axial Compression - When using the "Bi-axial Compression - SSSS" conditions, you must specify the ratio to be maintained between the transverse compressive load (global Y direction) and the axial compressive load (global X direction). Enter this ratio into the Ny/Nx Load Ratio box.
4. Calculate Results - After specifying all of the problem definition data and solution control data, click Calculate to compute the plate stability solution. The solution is shown in the display window. It consists of the laminated plate's critical buckling load expressed as a resultant force.