Learning Forum

[sriparna.2021rce15]

I am trying to model PZT patch (10mm x 10mm x 0.3mm) bonded on a beam (700mm x 150mm x 150mm) and perform coupled field harmonic analysis in order to obtain impedance (impedance vs frequency plot) The help manual for the: Mechanical Technology Showcase: Example Problems Chapter 39: Wire Bonding Ultrasonic Transducer states that the degree of freedom needs to be coupled as shown in fig.  So I tried to couple the bottom face of pzt patch (bottom voltage coupling) and top face of the PZT patch was coupled (tom voltage coupling). Then 0 Volt (voltage ground) is applied at the bottom face of the pzt patch and 1 Volt (voltage) at the top face of the pzt patch.  The physics region provided in model is as follows:          The model was executed, but following error came up.     In order to solve the analysis successfully, I tried removing the coupling and the analysis was performed. The results were as shown in below figure. According to me, I feel these results are not correct. Kindly tell me what I have done wrong so that I could get proper results of impedance.

[dlooman]

The set up you describe with coupling the top and bottom faces and setting one to 0 volt (ground) and the other to 1 volt seems correct.  It's not possible to read the error message.  Could you provide the text of the message?  

[sriparna.2021rce15]

Error is as follows: Invalid object scoping for current analysis: different load/conditions scoped to adjacent entities

 

Not applying coupling is ok?

[dlooman]

Yes, you don't need to couple volt.  You can just specify the voltage on the faces without coupling it.  Usually coupling is used for postprocessing purposes, but it's totally optional.