Chat with us, powered by LiveChat

Careers | Training | Resource!!!

arrow_back_ios

Main Menu

See All Products See All Knowledge See All Services & Support See All Solutions See All About See All Contact Us See All Demo See All Load cells title
arrow_back_ios

Main Menu

See All Acoustic End-of-Line Test Systems See All DAQ and instruments See All Electroacoustic application See All Software See All Transducers See All Vibration Testing Equipment See All Electroacousticsb - OLD unpublished See All Academy See All Resource Center See All Services See All Support See All Applications See All Industries See All Our Business
arrow_back_ios

Main Menu

See All Actuators See All Combustion Engines See All Durability See All eDrive See All Transmission Gearboxes See All Turbo Charger See All DAQ systems See All High precision and calibration systems See All Industrial electronics See All Power Analyser See All S&V Handheld devices See All S&V Signal conditioner See All Accessories for electroacoustic application See All DAQ See All Drivers API See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All Utility See All Vibration Control See All Acoustic See All Current / voltage See All Displacement See All Load cells See All Pressure See All Strain Gauges See All Torque See All Vibration See All Temperature See All LDS Shaker Systems See All Power Amplifiers See All Vibration Controllers See All Accessories for modal exciters See All Test Solutions See All Training Courses See All Primers and Handbooks See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Acoustics See All Asset & Process Monitoring See All Electric Power See All NVH See All OEM Custom Sensors See All Structural Integrity See All Vibration See All Automotive & Ground Transportation See All Business Ethics
arrow_back_ios

Main Menu

See All CANHEAD See All GenHS See All LAN-XI See All MGCplus See All Optical Interrogators See All QuantumX See All SomatXR See All Fusion-LN See All Accessories for industrial electronics See All Handheld Software See All Accessories for S&V handheld devices See All BK Connect / PULSE See All API See All Microphone sets See All Microphone Cartridges See All Acoustic calibrators See All Special microphones See All Microphone Pre-amplifiers See All Sound Sources See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All Accessories for strain gauges See All Non-rotating (calibration) See All Rotating See All CCLD (IEPE) accelerometer See All Charge accelerometer See All Impulse hammers / impedance heads See All Cables See All Accessories See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All Resources See All Electroacoustics See All Environmental Noise See All Noise Source Identification See All Product Noise See All Sound Power and Sound Pressure See All Vehicle Pass-by Noise See All Production Testing and Quality Assurance See All Machine Analysis and Diagnostics See All Structural Health Monitoring See All High Voltage See All OEM Sensors for the Agriculture Industry See All OEM Sensors for Robotics and Torque Applications See All Structural Dynamics See All Material Properties Testing

An Introduction to Shaker Testing

This Webinar was hosted at:

 Tuesday, May 12, 2020      02:00 PM CET       English

In this webinar, you will learn about shaker systems, including the history of how LDS Shaker Systems came to be. 

Additionally, this webinar will provide an introduction in to vibration testing and the theory behind it , along with learning how the product range provides solutions to many different challenges and applications seen by this interesting and fast evolving market.

A summary of topics include:

  • Brief history
  • Shakers - the how
  • The product range
  • Various applications
  • Value added testing

Speaker:

Brian Zielinski-Smith

Product Manager - Shakers & Amplifiers and Shaker Systems

Contact: 

brian.zielinski-smith@hbkworld.com

null

Download the Webinar Material

Presentation: An Introduction to Shaker Testing (PDF)

Handout: An Introduction to Shaker Testing (PDF)

Questions from Webinar Participants Answered by Brian Zielinski-Smith

This depends entirely on the product and its material properties. There are typical burn-in tests to find weaknesses in circuit boards, solder joints and electrical components that normally soak a product at extreme temperatures and can also include random vibration.

An example of these temperature soak tests could be –40 to +70°C for commercial parts, or –54 to +93°C for military components. The time at temperature is also variable and will depend on the thermal mass of the test item. The typical minimum is 2 hours with a maximum of 16 hours.

The ambient temperature, in situations where the amplifier might be in a hotter than normal environment, without climatic control, causes an amplifier to run hot.

This varies from system to system. All details can be found in the data sheets: https://www.bksv.com/en/instruments/vibration-testing-equipment/lds-shakers 

Actual displacement/motion of the armature differs from system to system and is dependent on the test profile being used. For information on displacement, please view the data sheets, which can be found on the website here: https://www.bksv.com/en/products/shakers-and-exciters 

The displacement is high at low frequencies (typically less than 20 Hz) as the acceleration amplitude will demand more movement to achieve the rate of change of velocity. This can be done through calculation at any frequency and any amplitude. If 3 sigma is used for random tests, then the theoretical peak value will be 3 × the RMS.

There are many factors to design your fixture and should be dealt with by an experienced design engineer. Some things to consider are:

  • Material preference is aluminium or magnesium alloys for strength to mass ratio and good damping properties
  • Low mass, high stiffness and a minimum thickness of 20 mm
  • Specified flatness tolerance and a good balance/C of G
  • All interface hole patterns should incorporate counterbored holes, which allow for a flat washer and cap head screw/bolt
  • Steel inserts should be used for interface to Jig
  • 100 mm minimum hole spacing, in a square pattern where possible and consider how to control and where to position the accelerometers using 10/32 threaded holes

The calculation for this is proprietary and does not include a dynamic setup with fixtures and products. This makes it difficult to accurately calculate without first taking a measurement. The voltage will vary with velocity and the current will vary with the acceleration and force requirement. However, the velocity and acceleration will also change with the characteristic of the overall setup and varies with frequency.

It is best to measure during a ‘low level’ test and confirm with your reference by using a proportion factor for future tests.

A drop test normally describes a physical drop onto a surface plate to observe impact damage. This is not a classical shock test or possible with a shaker. The shaker shock can be compared to a free fall shock machine and will successfully control various classical pulses.

Sine sweeps are often used to find the detail of resonances and can be used to test endurance or durability of a product as part of the initial development test.

Yes, via the vibration controller. PSD refers to a spectrum of random signals and is used as a control profile into the shaker. If the shaker has the frequency range of the test, it will respond to the drive signal and provide the overall spectrum requested by the PSD profile. The only restrictions will be the peak limits of your shaker in terms of D, V, A and Force against the demand PSD and overall GRMS calculation.

Generally, the accelerometer mass is insignificant to a beam and will only become an issue if the accelerometer used approaches the mass of the beam. If this ratio is better than 10:1, the error is well within the uncertainty of measurement stated on the overall test results.

This varies from system to system, all details can be found in the data sheets: https://www.bksv.com/en/instruments/vibration-testing-equipment/lds-shakers 

The lowest frequencies are for solid trunnion 1 Hz and for air isolated 5 Hz, but it will also depend on the test load. The highest achievable displacement depends on the size of the shaker, but typically an air-cooled medium range is ±25 mm between 5 Hz and 10 Hz.

Things to consider are the frequency range, the displacement and velocity limits and accuracy of control. These are all published and available for your own comparison on https://www.bksv.com/en/instruments/vibration-testing-equipment/lds-shakers 

The digital control system provides the adaptive control to the mechanical non-linear response of any shaker. The electrodynamic LDS shaker has protection to prevent overtravel and the PA will also have limits to prevent current and voltage if you try to run an impossible test. The transfer function is achieved by the controller and, if this is not possible, the controller will stop the test using various protective parameters and tolerances. The shaker limits are all held in the controller and will report any parameter failures before, during and after a test.

This is a performance versus cost question, as they are completely different. The cooling method is more complex with water cooled but similar in operation. The main difference is armature and field coils either incorporate water flow, or they have air flow, to remove excess heat. Our largest air-cooled shaker is 80 kN, but for better performance, LDS increases the cooling efficiency with a water chilling method.

Shakers can be very helpful when validating tyre-only models, whereby reference measurements are dynamic stiffness transfer functions. These measurements can’t be achieved on a rolling tyre test, which is best suited to the classical cleat test.

Repeatability, statistical DOF improvement, reliability, measurement, resonant accuracy and control can be an advantage over impact hammers. Nevertheless, hammers are cheaper, quicker, easier to use and often accurate enough if you are an experienced user.

You need to protect the shaker with thermal barriers. You will also need temperature-resistant accelerometers and cables. Moreover, the calibration of the accelerometers will require temperature inclusion. And you must use an isolated stud for the attachment of accelerometers. When finishing the test, you must avoid temperature shock and control the environment back to ambient temperature before entering the enclosure.

Yes. This is all part of the control software and the demand is flexible. You can manually or automatically set a desired frequency (within the range of the shaker).

Yes, but only for a very short period, otherwise damage may occur and reduce the life of the shaker components. For the best results, you should always stay around the 80% rated capacity. This is the same for all shakers on the market.

In addition to this, we would state that you should size the shaker to be above this rating to prevent issues caused by measurement errors, dynamic responses, control position tolerances and overall calculation errors of practice vs theory. 100% is achieved at the factory under strict conditions but we do not expect our customers to try this. The maximum values are there as a performance guide of a perfect setup to provide limits for the 80% calculation. There is typically a 10% overall uncertainty of measurement, which means that 90% limitations are already restricting the actual measured capability.

A linear sweep is in Hz/sec, the log sweep option is typically Oct/minute but can also be Dec/min. Therefore, a linear sweep test time is the range multiplied by the number of Hz every second. A log sweep uses a log calculation:

For clarification, RoR and SoR are described in most test specifications:

  • Random-on-Random: narrow bands of noise sitting on a broader band of random energy
  • Sine-on-Random: single tracked pure sine frequencies sitting on a broader band of random energy

The actual control is still completed by the accelerometer measurement feedback by calculating the acceleration amplitude equivalent to displacement at each frequency. The transition frequency can be calculated by comparing the increase in acceleration with the displacement constant:

G = Constant 9.80665 m/s² or 386.0885826772 in/s²

D = Displacement peak to peak

Contact us if you have any questions regarding the webinar topic or would like to be contacted by one of our technical experts.

Related Pages

No more result to load

Modern Slavery Statement     Imprint    Cookie Policy    Privacy Policy    Sitemap    Ethical Business

 

© 2025 Hottinger Brüel & Kjær

 

 

close
nCode logo
Graphics Brand

We haved moved ${referer} to www.hbkworld.com

 

This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.

close
ReliaSoft-Logo-webp
Graphics Brand

We haved moved ${referer} to www.hbkworld.com

 

This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.

close
Prenscia HBM-Logo rgb
Graphics Brand

We haved moved ${referer} to www.hbkworld.com

 

This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.

close
HBM-Logo blue rgb
Graphics Brand

We haved moved ${referer} to www.hbkworld.com

 

This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.

close
logo of Brüel & Kjær (BKSV), experts of sound and vibration measurements from HBK
Graphics Brand

We haved moved ${referer} to www.hbkworld.com

 

This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.