Testing in Combined Dynamic Environments

The combined dynamic environments of vibration and linear acceleration are common to a large number of spacecraft components and other devices. Testing such devices has normally been a two-step process in which independent vibration and centrifuge tests are performed. There is a concern that the combined effects from these two dynamic environments could cause unexpected operational failures that were not predicted from either analysis or independent testing. This paper describes the design and performance of a testing facility that combines vibration and centrifuge testing in a single operation. The test facility is called the Vibrafuge and utilizes Sandia National Laboratories' (SNL) 29-ft underground centrifuge with an attached electrodynamic shaker. Also addressed are activities underway at SNL on development of combined vibration and acoustic test facility (ATF).