Layered Cantilevered Beam (PSI-5H Piezo on top, Aluminum in middle, PSI-5H on bottom)

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  • Last Post 08 October 2018
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jonespa87 posted this 24 September 2018

I am new to the energy harvesting research area.  I have a cantilevered beam with piezo material on top and bottom with aluminum sandwiched between.  I have one end fixed and the other end deflected in -Y direction.  I also have CIRCU94 resistor coupled to top and bottom to measure output voltage.

I am receiving the following error.  "There are elements with negative electric charge and current conduction reaction solutions for the VOLT degree of freedom in the model.  This analysis is not valid."

So, the question I have is "What settings do I need to change to eliminate this error?"

Thank you,

Phil

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simaoka posted this 08 October 2018

Hi Phil,

Did you define and assign the piezoelectric material (TB,PIEZ) to the appropriate elements?  If you have thermal-electric elements (KEYOPT(1)=1001 for SOLID22x or PLANE223) but no piezoelectric material assigned to them, then the solver thinks they are electrostatic-structural elements and will give you the error message you provided.

Regards,
Sheldon

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jonespa87 posted this 08 October 2018

Hi Sheldon,

I have SOLID5 elements defined now with the proper piezoelectric material assigned.  The error has been eliminated.  Thank you for your help.

Phil

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