Hill Air Force Base, Utah

The multi-axis vibration system supplied by Wyle Laboratories to Hill AFB in Utah is the most sophisticated multi-axis shock and vibration device in the world today. With the ability to simultaneously input vibration energies on all three axes, the system can impose the synergistic effects that characterize the multi-dimensional vibration conditions encountered in a launch situation on missile subsystems.

The system provides the capability to conduct random sine, shock, shock response spectra (SRS), sine-on-random and random-on-random types of tests. It comprises four major subsystems as follows:

Vibration and shock generating system (the shakers)
Control system
Specimen table with bearings and support elements
Seismic mass on which the system is mounted

The vibration mechanism comprises a set of eight exciters (shakers), four in the vertical axis and two in each of the horizontal axes. Those that drive the horizontal axes operate in pairs in a push/pull configuration.

Each set of shakers provides up to 60,000 pounds-force (267 kN) to the axis that it serves during transient shock excitation. The exciter is an off-the-shelf, catalogue item with a history of performing in a reliable fashion. Water cooling is accomplished with a single heat exchanger system.

Because the exciters are used in multiples as opposed to installing a single very high force unit in each axis, the system functions in an active mode where exciters compensate for all the inertial loads and overturning moments in real time. This balanced performance precludes the need for the table restraints to eliminate the rotational tendencies characteristic of early designs.

This ability to operate in an active mode is a major design breakthrough that was made practical by several recent technology developments, most significant of which are the improvements made in the data processing speed of the control system computers.

For more information, please contact Wyle at:
service@wylelabs.com