Vibration machines are crucial to test the forces that make things fall apart in the bumpy real world, from small components to complete systems like airplanes or nuclear weapons. Large, high-frequency vibration machines that shake things in several directions simultaneously are relatively new. Sandia National Laboratories has developed a large, high-frequency, 6-degrees-of-freedom (6DOF) vibration machine to qualify weapons components and revolutionize the way it does mechanical testing.

Sandia National Laboratories’ 6DOF vibration machine research team members adjust accelerometer cables on a block head test item. (Photo by Randy Montoya)

The machine has 12 barrel-like electrodynamic shakers, four on each side for the horizontal X and Y axes, and four underneath for the Z, or vertical, axis. Using the various shakers together in different configurations achieves rotations around each axis. The shakers, which exert 4,000 pounds of force per axis, drive a 30 x 30 x 14” rectangular block in the center where a test piece sits.

The machine is meant for component- or subsystem-level tests. Sandia has performed two experimental 6DOF tests of nuclear weapons components, one for the B61-12 and one for the W88 ALT (alteration) 370.