Learning Forum

[Phil J]

Good Morning,

I am building a cantilevered beam piezo model with adjacent resistor to measure power generated.  I am using the Piezo and MEMS extension in workbench.  While using the example "Piezo fan" with the extension, I am able to run the model with success.  I am able to get a voltage response.

Now, I need to add a resistor (CIRCU94) element and measure power being generated during a harmonic response simulation.  Attached is my archived WB project.  The project shows the successful model without the resistor.  It also shows the unsuccessful model with an attempt to add the resistor.  Would you please help me figure out how to get the resistor to work?

Thank you,

Phil Jones

Penn State, Erie, PA

[Phil J]

Good Morning,

I am able to get the simulation to run now.  However, it is still not recognizing the CIRCU94 element and nodes.  Hum.  I will attach the latest project schematic for your assistance.

Thank you,

Phil

[Phil J]

I figured out my error.  I just needed to use the nodes already present on the beam element for the resistor.  It seems to be working now.

[K Jegadeesan]

Hi Phil, I have modelled the beam with PZT using Piezo&MEMS ACT, Also I have created the voltage coupling in the top and bottom of the PZT, and I got the node. I tried to add a resistor using CIRCU94 element, by using the following

ET,5,CIRCU94,0

R=3000

R,1,R 

TYPE,2

E,NTOP,NBOTTOM

 

but I the values of the voltage is not changing based on the resistance. 

You mentioned here that you figured out the error, can you help me in this. What i suppose to change. 

[Punnag Chatterjee]

Hi Jones,

 

Is it possible to attach the final error free workbench archived file here so I can learn from it and use it for a different application? Thanks in advance.

[Phil J]

Sure.  The project schematic shows the isotropic modal, the harmonic response without a load resistor, and then there is the anisotropic harmonic response with the load resistor.  I hope it helps.

Phil Jones

[jj77]

Great jonespa87, very interesting.

 

I did a small example, to show, basically connecting the circu94 to the existing mesh on pzt patch, that was missing initially.

 

Now it is coupled to the plate via the ACT coupling, very nice.

 

Thanks again for posting this

[Phil J]

Good Morning,

I have a new question about the Piezo and MEMS extension usage for energy harvesting.

My workbench model has been running fine.  I am able to simulate voltage response using various resistor values on my CIRCU94 element.

However, when I use a low resistance (for example < 7000 ohms), the simulation solves but the voltage response result has a red lightning bolt and no voltage response plot is generated.  It seems as though when it gets close to "closed" circuit, the voltage response will not be produced.

Is there something I need to change in the settings to get a result with low resistance?

Thank you,

Phil

[nilszbh]

Hi,

 

I am using the same extension to model a piezoelectric harvester, and having some questions in my simulation:

 

1- I get very high and very low voltages (varying from 10e-6  to 10e6 volts). I have defined a ground voltage node, but still getting weird voltages. 

2- voltage is not defined for all the parts of the model. I have the error of: 

"The user defined result might not be calculated successfully wholly or in some areas.

    There are some elements (or nodes) which do not contain

    data for the expression in: 310HARMONIC = VOLT

 

    Note that the result data may not be contained in the result file

    or may not be applicable to some element types.

    Also note that the solver module can create elements,

    such as surface effect or interface elements,

    whose results cannot currently be scoped in a contour display."

 

3- the solver doesn't let me define the ground voltage on the same node that I have voltage coupling with one side of my piezo components. The error  I get is : 

 

"Specified constraint not allowed on slave degree of freedom in coupled 
 set.                                                                   
  Coupled set number 1 First node= 222 Slave node = 31935 Degree of     
 freedom = VOLT.                                                        
  Move Move constraint to first node or remove coupling and constrain   

 all.  " 

 

I would appreciate if you could give me any related tips. Thanks in advance!

[Guoyang]

Hi, I met this problem as well. Have you known how to solve it? 

[MaiRabie]

Hello,

good day!

I am trying to regenerate the same piezoelectric harvester you modeled. However, the voltage output turns to be always zero. Am I missing any information here?

Thanks in advance

Regards,

Mai 

[Michael578]

Hello jonespa87,ngood day!nI am trying to simulate similar bimorph piezoelectric harvester with above commands. However, the output power and voltage doesn't change with resistor value.nAlso, I tried to check this issue in your model, but the output power doesn't change with resistor value.ET,10,CIRCU94,0 !SET UP RESISTORnR,1,100000 !RESISTANCE VALUEnTYPE,10 !SET ELEMENT TYPEnE,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2nnThanks in advancenRegards,n