A comparison of fixed-base and driven-base modal testing of an electronics package
This paper compares results for a fixed-base and a driven-base modal test of an electronics package. A fixed-base modal test uses the common testing procedure of attaching the structure to a large inertial mass which is freely suspended. The problem with this approach is that the input levels are typically limited by the size of the shakers and the strength of the attachment. An attractive alternative to fixed-base modal testing is to use stationary vibration shaker tables to provide a driven-base input. The modes can be obtained at much higher excitation levels than fixed-base excitation modes using portable shakers and flexible attachments. Experimental results are presented which demonstrate the adequacy of using vibration shake tables to excite the fixed-based modes of the system. A direct comparison of the modes acquired using fixed-base and driven-base excitation for the electronics package shows very close agreement. A discussion of the theory for driven-base testing is given, as well as a brief presentation of analytical (finite element) predictions for the structure. 4 refs., 11 figs., 1 tab.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6623678
- Report Number(s):
- SAND-88-1765C; CONF-890152-1; ON: DE89002364
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
420200 -- Engineering-- Facilities
Equipment
& Techniques
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
DATA
DYNAMIC LOADS
ELECTRONIC EQUIPMENT
EQUATIONS
EQUIPMENT
EXPERIMENTAL DATA
FINITE ELEMENT METHOD
FREQUENCY RESPONSE TESTING
INFORMATION
MATERIALS TESTING
MECHANICAL TESTS
MECHANICAL VIBRATIONS
NUMERICAL DATA
NUMERICAL SOLUTION
TESTING
THEORETICAL DATA