Cantilever piezoelectric experiments

[Grasscut]

Hi,

i need to conduct an experiments on a cantilever beam with a piezoelectric material bonded onto the surface of the beam. I have USB X SERIES NI USB-6356, NI USB-6366 DAQ available for me to use, but i have no idea how to use or configure it for the experiments. the things that i would like to obtain are the voltage and current from the piezoelectric material, the natural frequency of the cantilever beam when its subjected to base excitation using a shaker etc. i also have a polytec LDV CLV-3D which can be used to measure the natural frequency of the beam. So, i would like to seek assistance on how can i obtain all this result by using the DAQ. which software allows the capture of the result? if its LabView, do i have to create my own platform to measure?

hope someone can help me out. im totally new to this.

any help is appricated. thank you so much

[johnsold]

Piezoelectric materials typically generate a charge when strained. The DAQ devices are designed to measure voltage. So you need to convert the charge signal from the piezoelectric material to a voltage which can be measured by the DAQ device. The manufacturer of the piezoelectric material problaby has information about suitable circuits or equipemt for that conversion.

Once you have a voltage signal, then you can start thinking about the software.

Lynn

[Grasscut]

thanks for the quick reply.

Lets say im using this standard circuit which has a full bridge rectifier and the R1 is the load, i will be measuring the voltage of the piezoelectric from the resistive load then? what software would be recommended to analyse the result?

[johnsold]

Start with some of the DAQ examples, such as a continuous acquire and graph VI. (I do not have DAQmx or the examples so am not sure of the exact name.) That should let you get some data to see if your system works. Then you can adapt the examples to serve as subVIs in your main program.

Lynn

[Grasscut]

Thanks for the reply Lynn. i saw one of the example fro LabView as you mentioned on continuous acquire.

May i know how do i come about for the connection from the experimental setup to the DAQ to retrieve the data?

[johnsold]

The instruction manuals for the DAQ devices usually show how to make the connections.. For the most simple case connect parallel to R1 in the circuit diagram you posted  to one channel of the DAQ. If you know the value of R1, then you can measure the voltage across it and calculate the current.

Lynn