Learning Forum

[YANG GUORUI]

About simple piezoelectric simulation analysis.

I have tried piezoelectric simulation analysis of simple models many times in ansys workbench 2023R1, but I can't come to a conclusion, so I want to ask for help here.

Here is my operation flow:
1. Click Manage Extensions in the Extensions tab and load the PiezoAndMEMS-2020.1 version plug-in.
2. Open the nsys workbench 2023R1 interface and add a static structure project card to the project schematic.
3. Add the required material types in the engineering data. (PZT-5H)
4. Right-click the geometric structure and import the drawn geometric model .X_T file.
5. Double-click the model to enter the mechanical interface.
6. Define the Part1 material as PZT-5H in the geometric structure on the left.
7. Right-click the mesh and click Generate Mesh.
8. Insert Piezoelectric And MEMS Body in the static structure on the left, select the model, and define it as the global coordinate system.
9. Insert fixed support and pressure (size 1000Pa) into the static structure on the left respectively.
10. Insert the voltage in Electric Results into the solution.
11. Click Solve.

Then two error reports will be displayed:
1. A solver pivot warning or error was detected in %3 degrees of freedom at node %1 at %2. This is usually caused by poorly conditioned matrices, which may be due to unreasonable material properties, restricted models, or contact-related issues. Double check the results. You can select conflicting objects and/or geometries via RMB on this warning in the Messages window.
2. A solver pivot warning or error has been encountered during the solution process. This is usually caused by poorly conditioned matrices, which may be due to unreasonable material properties, restricted models, or contact-related issues. Double check the results.

What should I do to get the correct result.
Looking forward to your reply.

[Dave Looman]

You didn't mention specifying the ground voltage.  That would explain the pivot messages.

[Bill Bulat]

In addition to what Dave suggested, I would recommend using a Coupled Field analysis system without the Piezo & MEMS ACT. Piezoelectric analyses are now natively supported in Mechanical - the Piezo & MEMS ACT is no longer necessary. Additionally, the ACT may not work properly in newer releases of Workbench.