Structural Excitation
Efficiency or Accuracy?
Efficiency would be…. when you do not have to find supports for large shakers, adapt stingers and force cells, and adjust height, adjust alignment, check quality and adjust again. Or alternatively go through tedious hammer impacts to obtain a set of sufficient accuracy. Imagine shakers which are much smaller, lighter, with a high force density, self-supporting with an integrated self-aligning suspension. Performing excitation at two/three/multiple locations, and potentially multiple variants of modified test-objects, becomes highly efficient.
Accuracy would be…… when you do not have to worry about exact hammering or mass loading of the test-structure. When shakers have an internal compliant suspension system, and they are self-aligning in any inclination, and do not require a heavy stinger attachment and force sensor on your test-object, measurements become accurate and repeatable.
self aligning and self supporting
low coupled mass
highest force density; compact
integrated force sensing
patented suspension systems
The Qsources shakers present the highest force density in the industry, making them much smaller and lighter. And they have patented internal decoupling suspension systems, and they have integrated non-contact force sensing. When applied in their intended frequency range, this combination ensures they are both efficient and accurate.
The possibility to excite in any inclination, in narrow spaces, is essential for transfer path and inverse load identification techniques. It is very useful for Modal and CAE model correlation measurements, and it also opens up the potential of new measurement techniques.
Each shaker is tuned for a object size range and for a frequency range. And you will find that measurements on large structures with small shakers is well possible. The patented self-aligning suspensions makes sure that the test-object can vibrate in their natural way. The shakers are always aligned and measurement reproduction is better than any other excitation on the market.
Diameter 20 mm
Typical test-objects 0.6 kg to 800 kg
Core frequency range 250-8000 Hz*
Extended frequency range 63—12500 Hz**
Force level, 0.8 N RMS random broadband
Force sensor integrated and in-line accelation sensor on request
Diameter 20 mm
Typical test-objects of 0.6 kg to 800 kg
Core frequency range 250-8000 Hz*
Extended frequency range 63—12500 Hz**
Force level, 0.8 N RMS random broadband
Force sensor integrated
Diameter 27 mm
Typical test-objects from 2.5 kg to 2000 kg
Core frequency range 200-5000 Hz*
Extended frequency range 50-6300 Hz**
Force level 2 N RMS random broadband
Integrated force and acceleration sensing
Diameter 29 mm
Typical for objects from 2 to 10.000 kg
Core frequency range 25-2000 Hz*
Extended frequency range 8-3150 Hz**
Force level 10 N RMS broadband random
Exceptional low coupled mass
Integrated force sensor and in-line acceleration module
Diameter 40 mm
Typical test-objects from 2.8 kg to 10.000 kg
Core frequency range 25-1800 Hz*
Extended frequency range 8-2500 Hz**
Force level 10 N RMS random broadband
Force sensor integrated and in-line acceleration module
Diameter 44 mm
Typical test objects up to 25.000 kg
Core frequency ranges 3.15-20 Hz and 40-500 Hz*
Extended frequency range 4-500 Hz**
Force level 25 N RMS random broadband
Integrated force sensor
Exceptional long stroke of 42 mm pkpk
Allowing 3-axis direct- and cross-impedance measurements
Intended for limited access spaces, with a 20 mm footprint
Typical test-objects from 50 kg to 10000 Kg
Internal 3D acceleration sensing in the 8-1500 Hz frequency range
Typical for objects from 60 to 100.000 kg
Diameter 72 mm, 175 mm length
Core frequency range 25-1000 Hz*
Extended frequency range 6.3-1250 Hz**
Force level 80 N RMS random broadband
Integrated force sensor
Light weight 8.1 kg
Portable and battery driven
Within all ISO 16283-2 requirements
Suitable for any building, ship, industrial, etc. application
High accuracy
Single channel measurement amplifier for multiple sources/shakers
Efficient intuitive controls
Power+- 700 Watt
Core frequency range 5-40000 Hz
Range of amplifiers, tuned to shakers/sources
From base version to processor controlled DSP
High accuracy
Compact light weight +-1.7 to 2.6 kg depending on version
Power +- 700 Watt
Core frequency range 5-40000 Hz
*What is core frequency range?
If a very high accuracy is essential it is advised to remain within the core frequency range for the typical test-object mass range. This is the range frequency range where the shaker was designed for and has its highest force level.
**What is extended frequency range?
High accuracy in the extended frequency range is possible on the heavier objects. Or for lighter objects In some applications, like troubleshooting, fast application on many locations is needed. And in other applications, like load identification and transfer path analysis, access is only possible with a small shaker. In those cases a lower accuracy or higher risk of error is accepted and the extended frequency range is used.
In all cases a reciprocity verification and two shaker coupling/decoupling verification can be applied to prevent misinterpretation of measurement results.
The Application Field
To allow a better insight into which shaker is best for your test-object, the frequency vs test-object mass range in kg is indicated. Masses ranging from the weight of mobile phone, dishwasher, car, to a steel bridge.
The graphs use a few assumptions:
using quality accelerometers for responses
using a quality measurement system
limited background vibration and noise
rigid body behavior or low modal density of the test-objects at the lowest frequencies
high modal density of the test object at the highest frequencies, adapted to each shaker
around 1% of modal damping resolution
connecting the shaker to the stronger, more stable locations on the test-object, not on a weak location
This way of presenting the application field is new, and still in development. It indicates likeliness of accurate results.
