arrow_back_ios

Main Menu

See All Acoustic End-of-Line Test Systems See All DAQ and instruments See All Electroacoustics See All Software See All Transducers See All Vibration Testing Equipment See All Academy See All Resource Center See All Applications See All Industries See All Insights See All Services See All Support See All Our Business See All Our History See All Our Sustainability Commitment See All Global Presence
arrow_back_ios

Main Menu

See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors 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 Hand-held devices See All S&V Signal conditioner See All Test Solutions See All DAQ Software 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 LDS Shaker Systems See All Power Amplifiers See All Vibration Controllers See All Accessories for Vibration Testing Equipment See All Training Courses See All Whitepapers See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All Our People
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 Accessories See All Accessories 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 See All Non-rotating (calibration) See All Rotating See All CCLD (IEPE) accelerometers See All Charge Accelerometers See All Impulse hammers / impedance heads See All Cables See All Accessories See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

A Shakers armature life

While HBK LDS shakers are extremely robust, the armature is a living component, whereby the high numbers of stress cycles, high stresses and high temperatures will ultimately lead to failure and the need for replacement. The time taken for an armature to fail depends on:

  • The force level at which it is running
  • The type of test
  • Other factors that will influence its life 

The force level

As a guide, HBK LDS shakers have an expected life of over 10,000 hours when running at 80% force. At force levels below 80% the expected life will be longer; at levels above 80% it will be shorter. This relationship is non-linear, being based on SN curves, which approximate to a straight line only on a log-log scale.

 

The type of test

Armature life is also affected by the type of test being run as shown below (higher values lead to reduced life):

 

Type of Test         Value        
 Sine Sweep             1
 Random broadband (20 - 2000 Hz)             1 
 Shock            1.5
 Shock response spectrum (SRS)             2
 Sine on Random             2 
 Narrowband random             2            
 Fixed frequency sine             3 

 

The expected armature life can be calculated by dividing the value of the type of test into the rated life for the force level used. For instance, the expected life of a fixed frequency sine test run at 80% force is approximately 10,000/3 = 3000 hours.

Other Risk Factors

Other risk factors that can lead to a reduction in armature life are as follows:

  • High temperature of raw cooling air or water
  • Distortion caused by ‘slapping’ components
  • High ‘g’ levels
  • Humid or dusty environments
  • High frequency > fn
  • Large displacement
  • Horizontal running
  • Running under a chamber
  • Large overturning moments applied
  • High velocity
  • Drive high
  • Lively payload
  • Poor control
  • Not keeping reference plots
  • Poor maintenance
  • Unattended operation
  • Large payloads 

 

The maximum armature life will be obtained when the above factors are avoided as much as feasibly possible, all while using the shaker within its specified performance range.

Support Content