APS Dynamics Inc. designs and manufactures mainly Long Stroke Vibration Exciters for the low frequency range. The ELECTRO-SEIS® shakers are available in two different configurations – ball bearing type shakers and air bearing type shakers.
For sensor calibration applications or testing applications that require a smooth motion of the exciter, the APS Shakers feature air bearing armature guidance for exceptionally clean waveforms with wide dynamic range and very low cross-axis motion.
The ball bearing shakers are used primarily for modal test excitation or environmental test applications in the low frequency range < 200 Hz. Although these shakers have a long stroke (158 mm) they are still portable. Thus APS ELECTRO-SEIS® shaker are ideal tools for testing of bridges, buildings or other objects outside a laboratory.
Examples of shaker applications: Excitation of bridges to test dynamic properties
Have you ever heard of the tragic collapse of Tacoma Narrows Bridge in 1940 which was later called the “Pearl Harbor of engineering“? Unfortunately, the structure of the bridge had not been tested the way our APS shakers can test its dynamic properties.
Earthquake Simulation, Field data replication
Sine excitation of forklift structure
Boeing Commercial Airplanes
The APS 400 and 420 shakers were used to do modal testing at the large jet engine.
US Geological Survey
Measuring the dispersive nature of surface waves in the ground (using APS 400)