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Title: Shape-constrained Input Estimation for Efficient Multi-shaker Vibration Testing

Journal Article · · Experimental Techniques
ORCiD logo [1];  [2]
  1. Univ. of Massachusetts, Lowell, MA (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Univ. of Massachusetts, Lowell, MA (United States)

Multi-shaker vibration testing is gaining interest from structural dynamics test engineers as it can provide a much more accurate match to complicated field vibration responses than traditional single-axis shaker tests. However, the force capabilities of the small modal shakers typically used in multi-shaker vibration tests has limited the achievable response levels. To date, most multi-shaker vibration tests have been performed using a variety of standard, commercially-available control systems. While these control systems are adequate for a wide range of multiple-input/multiple-output tests, their control algorithms have not been tailored for the specific problem of multi-shaker vibration tests: efficiently coordinating the various shakers to work together to achieve a desired response. Here, a new input estimation algorithm is developed and demonstrated using simulations and actual test data. This algorithm, dubbed shape-constrained input estimation, is shown to effectively coordinate multiple shakers using a set of constraint vectors based on the deflection shapes of the test structure. This is accomplished by using the singular vector shapes of the system frequency response matrix, which allows the constraint vectors to automatically change as a function of frequency. Simulation and test results indicate a significant reduction in the input forces required to achieve a desired response. Finally, the results indicate that shape-constrained input estimation is an effective method to achieve higher response levels from limited shaker forces which will enable higher level multi-shaker vibration tests to be performed.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sandia National Laboratories, Unknown, Unknown
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC04-94AL85000; NA0003525
OSTI ID:
1617298
Report Number(s):
SAND-2019-14871J; 682354
Journal Information:
Experimental Techniques, Vol. 44; ISSN 0732-8818
Publisher:
WileyCopyright Statement
Country of Publication:
United States
Language:
English

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