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

Journal Article · Tue Mar 17 00:00:00 EDT 2020 · Experimental Techniques

DOI:https://doi.org/10.1007/s40799-020-00361-0· OSTI ID:1617298

Schultz, Ryan ^[1]; Avitabile, Peter ^[2]

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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 Laboratories (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
• Alternate ID(s): OSTI ID: 1763161; OSTI ID: 1642864
• Report Number(s): SAND--2019-14871J; 682354
• Journal Information: Experimental Techniques, Journal Name: Experimental Techniques Vol. 44; ISSN 0732-8818
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
MIMO
control algorithm
input estimation
multi-shaker testing
singular value decomposition
vibration testing