Mechanical APDL Structural Analysis Guide

tolerance defaults to 0.0, so that the response first order eigenvalues can be used to more precisely

determine a new time step value.

Note

If you are using the Solution Controls dialog box to set solution controls, you can access

all of these options (ALPHAD,BETAD,KBC,TIMINT,TINTP,TRNOPT) on the Transient

tab.

3. Write load data for each load step to a load step file.
   Command(s):LSWRITE
   GUI: Main Menu> Solution> Load Step Opts> Write LS File


4. Save a backup copy of the database to a named file.
   Command(s):SAVE
   GUI: Utility Menu> File> Save As


5. Start solution calculations. Other methods for multiple load steps are described in Getting Started in the
   Basic Analysis Guide.
   Command(s):LSSOLVE
   GUI: Main Menu> Solution> Solve> From LS Files


6. After you have solved all load steps, leave SOLUTION.
   Command(s):FINISH
   GUI:Close the Solution menu.

8.7.3. Review the Results

As in a nonlinear static analysis, you can use POST1 to postprocess results at a specific moment in time.
Procedures are much the same as described previously for nonlinear static analyses. Again, you should
verify that your solution has converged before you attempt to postprocess the results.

Time-history postprocessing using POST26 is essentially the same for nonlinear as for linear transient
analyses. See the postprocessing procedures outlined in Transient Dynamic Analysis (p. 107).

More details of postprocessing procedures can be found in the Basic Analysis Guide.

8.8. Example Input for a Nonlinear Transient Analysis

Following is an example input listing for a nonlinear transient analysis:

! Build the Model:

/PREP7

---! Similar to a linear full transient model, with

---! these possible additions: nonlinear material

---! properties, nonlinear elements

---

FINISH

!

! Apply Loads and Obtain the Solution:

/SOLU

ANTYPE,TRANS

! TRNOPT,FULL by default

---! Establish initial conditions as in linear full

---! transient analysis

LSWRITE! Initial-condition load step

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Nonlinear Structural Analysis