Understanding and exploiting the nonlinear behavior of tuned liquid dampers (TLDs) for structural vibration control by means of a nonlinear reduced-order model (ROM)

We present computationally efficient models and approaches and utilize them to investigate the dynamics of microbeams under mechanical shock. We explore using a hybrid approach utilizing a beam model combined with the shock spectrum of a spring-mass-damper model. We conclude that this approach is computationally efficient and yields accurate results in both quasi-static and dynamic loading conditions. We utilize a reduced-order model based on the nonlinear Euler-Bernoulli beam model. We demonstrate that this model is capable of capturing accurately the dynamic behavior of microbeams under shock pulses of various amplitudes (low-g and high-g), in various damping conditions, structural boundaries (clamped-clamped and clamped-free), and can capture both linear and nonlinear behavior. We investigate high-g loading cases. We report significant increase in the computational cost of simulations when using traditional nonlinear finite-element models because of the activation of higher-order modes. We demonstrate that the developed reduced-order model can be very efficient in such cases.

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Experimental Study on Arrangements of Setting Points of an Actuator and Sensor for the Vibration Control of Flexible Structures

Journal of Robotics and Mechatronics ◽

10.20965/jrm.1994.p0292 ◽

1994 ◽

Vol 6 (4) ◽

pp. 292-297

Author(s):

Kazuto Seto ◽

◽

Katsuhiko Ezure ◽

Keyword(s):

Experimental Study ◽

Vibration Control ◽

Vibration Mode ◽

Controller Design ◽

Flexible Structures ◽

Reduced Order Model ◽

Displacement Sensor ◽

Order Model ◽

Reduced Order ◽

Dynamic Absorber

This paper proposes an experimental study on the arrangements between the setting points of an actuator and sensor for the vibration control of a flexible structure, when a vibration controller is mounted at an arbitrary position on the structure. The important vibration mode of the structure to be controlled is its first mode, because it is excited most sensitively by strong winds. It is therefore necessary to make a reduced-order model represented by a one-degree-of-freedom system at an arbitrary location, in consideration of preventing spillover instability. In this paper, non-observability is used for making the reduced-order model, and the LQ control theory is used for controller design. For controlling vibration, a reduced-order model is constructed at the setting point of a hybrid dynamic absorber, and a displacement sensor is set at the vibration node of the second vibration mode. Then, the setting point of the sensor is changed to compare control effects by means of this model. It is demonstrated experimentally that a hybrid dynamic absorber, designed by this method, is capable of controlling vibration well without causing spillover instability. In addition, it is considered that the setting point of the sensor influences the robustness of the control system.

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Reduced Order Model for the Geometric Nonlinear Response of Complex Structures

Volume 1: 24th Conference on Mechanical Vibration and Noise, Parts A and B ◽

10.1115/detc2012-71141 ◽

2012 ◽

Cited By ~ 5

Author(s):

Ricardo Perez ◽

X. Q. Wang ◽

Andrew Matney ◽

Marc P. Mignolet

Keyword(s):

Degrees Of Freedom ◽

Nonlinear Behavior ◽

Reduced Order Model ◽

Model Parameters ◽

Complex Structures ◽

Order Model ◽

Plate Structures ◽

Reduced Order ◽

Nonlinear Static ◽

Selection Of

This paper focuses on the development of nonlinear reduced order modeling techniques for the prediction of the response of complex structures exhibiting “large” deformations, i.e. a geometrically nonlinear behavior, and modeled within a commercial finite element code. The present investigation builds on a general methodology successfully validated in recent years on simpler beam and plate structures by: (i) developing a novel identification strategy of the reduced order model parameters that enables the consideration of the large number of modes (> 50 say) that would be needed for complex structures, and (ii) extending an automatic strategy for the selection of the basis functions used to represent accurately the displacement field. The above novel developments are successfully validated on the nonlinear static response of a 9-bay panel structure modeled with 96,000 degrees of freedom within Nastran.

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