The manual stimulation of a structure with a small modal hammer is almost impossible without a “double hit” – a well-known and very unpleasant problem! To solve this, MAUL-THEET has developed the product family of automatic modal hammers “vImpact”. This means that structures can be excited precisely and reproducibly and the excitation forces can be measured. The new models of the automatic modal hammer from MAUL-THEET are the vImpact-62, vImpact-61, the vImpact-21 and the vImpact-2001. The different types differ in the frequency range and the maximum excitation force. With the vImpact-2001 in particular, the excitation force can be set over a wide range, since the tips can be exchanged here.
The actuator of the vImpact models has been optimized to ensure double hit-free excitation of the test structure. Double hits must be avoided in any case, since the resulting “rough” excitation spectra can render a transfer function to be measured unusable. The actuator principle selected in the vImpact models ensures double hit-free excitation over a wide range of distances, i.e. a high-precision fixing of the hammer head or an elaborate set-up of the hammer position in relation to the test object is not necessary. Small displacements of the measurement object, which can occur with longer series of measurements, also have no influence on the selected impact excitation. Double hit-free impact excitations in quality assurance (“end of line tests” in serial production) are therefore possible without high-precision part positioning.
The actuators are designed for continuous operation, have no relevant wear parts and do not heat up. Depending on the type, model variants for a temperature range from -65 ° C to 150 ° C can be offered.
Our vImpact models do not need a computer for control and are therefore fully standalone functional.
With the vImpact-62, 61 and 61i models, no additional masses are applied to the load cells, which means that the hammer mass remains low. Depending on the surface hardness of the test object, frequencies of up to 60 kHz can be excited.
Unlike their predecessors vImpact-60, vImpact-20 and vImpact-2000, the new models have increased the maximum power of impact, especially during overhead excitation. At the same time, we have made them more user-friendly by reducing the number of controls and improving the ability to adjust the impact force. Furthermore, the signal cable can be grounded via a switch to improve the signal-to-noise ratio.
The vImpact system is divided into two components:
The hammer head includes the small Modal hammer who has an integrated force cell and the electro dynamic actor that moves the hammer. The control unit sends the impulse that moves the Modal hammer to the actor inside the hammer head. The measured force signal is at the output of the control unit available. The hammer can be triggered by several methods:
Manually with a button on the control unit
By closing the external input e.g. by a push button extension or by a third-party device.
Via a TTL pulse at the external input.
With the built-in timer in the range of 4 beats per second up to 1 beat per 1000s (16 minutes)
|Max. Impact force|
(Steel on Steel)
|> 150 N peak||> 150 N peak||> 2000 N peak||> 150 N peak||> 150 N peak|
(Steel on Steel)
|> 40 kHz||> 20 kHz||> 6 kHz||> 40 kHz||> 20 kHz
|Coupling||2-4 mA, IEPE||2-4 mA, IEPE||2-4 mA, IEPE||2-4 mA, IEPE||2-4 mA, IEPE|
|Trigger||Timer // Button// External Contact (Closer)// TTL (40 .. 200 ms)||Timer // Button// External Contact (Closer)// TTL (40 .. 200 ms)||Timer // Button// External Contact (Closer)// TTL (40 .. 200 ms)||Timer // Button// External Contact (Closer)// TTL (40 .. 200 ms)||Timer // Button// External Contact (Closer)// TTL (40 .. 200 ms)|
|Power Supply||24 V||24 V||36 V||24 V||24 V|
|Mass||Head: 0,41 kg, Controller: 0,6 kg||Head: 0,42 kg, Controller: 0,6 kg||Head: 4.9 kg, Controller: 0.6 kg||Head: 0,41 kg, Controller: 0,6 kg||Head: 0,42 kg, Controller: 0,6 kg|