Laser vibrometers will help you to develop efficient tools for ultrasonic processing applications. Already used in various industries for applications such as wire bonding, welding and food cutting, Polytec vibrometers are essential for FE model validation and verification.
Polytec Scanning Vibrometers are perfectly suited for the verification of numeric simulations of ultrasonic welding tools. Its inherent properties like
- full-field measurements (1D and 3D)
- linear frequency response
- high frequnecy bandwidth
- geometry import from CAE
allow for a quick evaluation of the uniformity of deflection at the active surface.
Case Study: 3D Sonotrode measurement
Measured with PSV-400-3D Scanning Vibrometer
- 7,641 DOF / 2,547 measurement points
- Bandwidth: 100 kHz
- Nominal operating frequency: 20 kHz
The deflection shapes were measured in 5 sections, using mirrors to get optical access to the active surface.
For the measurement the sonotrode was setup in a support with a mirror placed below to allow a view for the scanning laser vibrometer to the active surface. The sonotrode was excited with a periodic chirp signal from the PSV signal generator in order make a broadband excitation.
The object geometry with the nodes and elements was loaded into the PSV and aligned to the sonotrode with a simple referencing procedure (3D-alignment) in order to match the numeric geometry to the object in the video image of the PSV.
Deflection Shape 20 kHz
The measured deflection shape at 20 kHz shows a well designed sonotrode: The active surface moves up and down very uniformly. There are hardly now parasitic modes visible.
Deflection Shape at 7 kHz
If the frequency is shifted away from the driving frequency, other modes become dominant. In the example at 7 kHz the deflection shape will introduce in-plane motion to the active surface, which is not desired in this case