Mechanical APDL Structural Analysis Guide

7. Exit the SOLUTION processor.
   Command(s):FINISH
   GUI:Close the Solution menu.

7.5.4. Review the Results

Results from a buckling expansion pass are written to the structural results file,Jobname.RST. They
consist of buckling load factors, buckling mode shapes, and relative stress distributions. You can review
them in POST1, the general postprocessor.

Note

To review results in POST1, the database must contain the same model for which the buckling

solution was calculated (issue RESUME if necessary). Also, the results file (Jobname.RST)

from the expansion pass must be available.

1. List all buckling load factors.
   Command(s):SET,LIST
   GUI: Main Menu> General Postproc> Results Summary


2. Read in data for the desired mode to display buckling mode shapes. (Each mode is stored on the results
   file as a separat e substep.)
   Command(s):SET,SBSTEP
   GUI: Main Menu> General Postproc> Read Results> load step


3. Display the mode shape.
   Command(s):PLDISP
   GUI: Main Menu> General Postproc> Plot Results> Deformed Shape


4. Contour the relative stress distributions.
   Command(s):PLNSOL or PLESOL
   GUI: Main Menu> General Postproc> Plot Results> Contour Plot> Nodal Solution
   Main Menu> General Postproc> Plot Results> Contour Plot> Element Solution

See the Command Reference for a discussion of the ANTYPE,PSTRES,D,F,SF,BUCOPT,EXPASS,MX-
PAND,OUTRES,SET,PLDISP, and PLNSOL commands.

7.6. Sample Buckling Analysis (GUI Method)

In this sample problem, you will analyze the buckling of a bar with hinged ends.

7.6.1. Problem Description

Determine the critical buckling load of an axially loaded long slender bar of length ℓ with hinged ends.
The bar has a cross-sectional height h, and area A. Only the upper half of the bar is modeled because
of symmetry. The boundary conditions become free-fixed for the half-symmetry model. The moment

of inertia of the bar is calculated as I = Ah^2 /12 = 0.0052083 in^4.

7.6.2. Problem Specifications

The model is assumed to act only in the X-Y plane.

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Buckling Analysis