Linear buckling analysis of a panel with a bead

A panel is fully constrained at one edge and loaded by a force distributed around the bolt holes in the flange, see Figure 15. The edge at the flange is constrained in the transverse direction. The example keyword file is buckle001.key. First, a pre-loading of 32 kN is applied in a nonlinear implicit analysis, then a linear buckling analysis is performed. The lowest eigenvalue is 12.078, corresponding to a buckling load of 386.5 kN. The buckling mode shape is shown in Figure 16.

Example Files: buckle001
NOTE! All examples are included in the Complete Guideline

Main Input

*KEYWORD 
$===============================================================================
$ Bracket geo
$===============================================================================
*INCLUDE
buckling_geo001.key
$===============================================================================
$ Control and output cards
$===============================================================================
*INCLUDE
../INCLUDE_FILES/control_cards_linear.key
*DATABASE_HISTORY_NODE
       244
*INCLUDE
../INCLUDE_FILES/database_cards_static.key
*CONTROL_TERMINATION
        1.
*CONTROL_IMPLICIT_BUCKLE
         5
$===============================================================================
$ Loads and boundary conditions
$===============================================================================
*DEFINE_CURVE_TITLE
Force ramp
100,
0.,0.
1.,1.
*LOAD_NODE_SET
         2         2       100  1.333333
*BOUNDARY_SPC_SET
         1                   1         1         1         1         1         1 
         3                   1  
$===============================================================================
*TITLE
Linear buckling analysis
*END