The Method of Successive Decrease and the Concept of Harmonic Wave Filter in Structural Wave Control

1995 ◽  
Author(s):  
Dajun Wang ◽  
Quan Wang ◽  
A. Y. T. Leung
Keyword(s):  
Vibration Control ◽  
Structural Control ◽  
Natural Frequencies ◽  
Control Method ◽  
Harmonic Wave ◽  
Flexible Structures ◽  
Modal Control ◽  
Large Space ◽  
Wave Filter ◽  
Wave Control

Abstract Most of the available vibration control methods for flexible structures are based on the modal control method, which, however, sometimes meets with problems. For examples, the problem of spillover has not been solved adequately. And, for flexible large space structures with closely spaced natural frequencies, it is very difficult to use modal method to treat vibration control problems because the modes corresponding to closely spaced and repeated frequencies can not be computed accurately. In recent years, the method of structural wave control has been developed, but it has not been studied sufficiently. The object of this paper is an attempt to solve some of the existing problems raised due to the application of the modal control method. A wave control method — the method of successive decrease is set up at first, which is aimed at one harmonic wave. Then, a new design method in wave control is proposed, based on the above method. The problem of control spillover is analyzed and the concept of harmonic wave filter is introduced. As an example, the problem of the control of structures with closely spaced natural frequencies is treated by both the method of modal control and the method of successive decrease. The numerical results show that the method of successive decrease is more effective than the method of modal control. It proves that the method of successive decrease and the concept of harmonic wave filter is promising in solving the problems of structural control.

Vibration Control Using Connected Control Device for Two Identical Structures Arranged in Parallel

2005 ◽  
Author(s):  
Kiyofumi Fujimura ◽  
Kazuya Makita ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Optimal Design ◽  
Vibration Control ◽  
Passive Control ◽  
Natural Frequencies ◽  
Control Method ◽  
Dynamic Properties ◽  
Flexible Structures ◽  
Design Strategy ◽  
Control Device ◽  
Supporting Structures

This paper deals with vibration control using the optimal design strategy of the connected control device for flexible structures with same dynamic properties. One of the authors had already proved effectiveness of connected control method for vibration control of flexible structures arranged in parallel. However, its control performance is degraded as the natural frequencies of structures become closer. To overcome this problem, the authors present a modified control mechanism in which the actuators are connected to the structures with differences in its connecting position by using long arms named “supporting structures”. However, the optimal design strategy for vibration control device has not been established yet. In this report, the optimal design strategy of passive control is presented. Computer simulations and the experiments are carried out and the effectiveness of the presented vibration control designed by the connected control device is confirmed.

Research on Vibration Control of Thin Plate Based on Pre-Stressing

2018 ◽  
Author(s):  
Cheng Zhang ◽  
Jian-run Zhang ◽  
Xi Lu
Keyword(s):  
Differential Equation ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Vibration Control ◽  
Thin Plate ◽  
Natural Frequencies ◽  
Control Method ◽  
Dynamic Stiffness ◽  
Thin Plates ◽  
Shape Functions

The weak dynamic stiffness of thin plate is one of the important factors that limit the use of thin plate. Improving the dynamic stiffness of thin plate is one of the effective methods for the vibration control of thin plate. In this paper, the influence of pre-stress on the vibration characteristics of thin plate is studied. A vibration control method of thin plate based on pre-stress is proposed. The vibration differential equation of quadrate thin plate under pre-stressing is established. Using the Galerkin principle, the natural frequencies corresponding to the shape functions of the quadrate thin plates under pre-stressing in different distribution forms are obtained. By comparison, it is found that pre-stressing on the thin plate can change the dynamic stiffness of thin plate. In particular, tensile stress can increase the dynamic stiffness of thin plate while compressive stress can reduce the dynamic stiffness of the thin plate. The greater the pre-stress, the more obvious the effect. In the end, the requirements of the pre-stress distribution which can improve the dynamic stiffness of thin plate effectively are derived.

Vibration Control of Parallel Identical Flexible Structures Using Interactive Force

2001 ◽  
Author(s):  
Shigeru Kougo ◽  
Hiroshi Fujihara ◽  
Katsuhiko Yoshida ◽  
Hiroyuki Tanaka ◽  
Toru Watanabe ◽  
...  
Keyword(s):  
Vibration Control ◽  
Control Experiment ◽  
Natural Frequencies ◽  
Control Mechanism ◽  
Reaction Force ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Control Performance ◽  
Active Vibration ◽  
And Control

Abstract This paper deals with active vibration control of two identical flexible structures arranged in parallel. One of the authors had presented a vibration control mechanism so that two or more structures are connected via non-contact actuators in which one structure is utilized as a reaction wall for another structure’s control mutually. However, in such a mechanism, the control performance reduces as the natural frequencies of structures become closer. In this report, authors present a modified mechanism in which actuators are connected to the structures with long arms so that the direction of vibration in a mode differs on each structure. In this way, the reaction force from the actuator on structure is introduced to another structure for dissipative force even if the properties of structures are identical. Computer simulation and control experiment are carried out and the effectiveness of presented mechanism is confirmed.

Dynamic Analysis of Sandwich Beams Filled with ER Elastomers

2011 ◽  
Vol 50-51 ◽  
pp. 843-848 ◽  
Author(s):  
Quan Bai ◽  
Ke Xiang Wei ◽  
Wen Ming Zhang
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Vibration Control ◽  
Natural Frequencies ◽  
Flexible Structures ◽  
Sandwich Beam ◽  
Element Model ◽  
Sandwich Beams ◽  
Simulation Results ◽  
Er Fluids

Considered electrorheological (ER) elastomers as the visco-elasticity material, a finite element model of a sandwich beam filled with ER elastomers was developed based on Hamilton’s principle and sandwich beam’s theory. Then its dynamic characteristics were analyzed. Simulation results show that natural frequencies of the sandwich beam increase and vibration amplitudes of the beam decrease as the intensity of applied electric field increases. Increased the thickness of the ER elastomers layer, natural frequencies of the beam decrease and loss factors increase. Those indicate that the dynamic characteristic of ER elastomers sandwich beams is similar as that of ER fluids beam, which can be used for vibration control of flexible structures by applied a electric field.

Vibration and Motion Control of Flexible Structures by Hybrid Dynamic Absorber(Influence of Vibration System with Nonlinear Element)

1994 ◽  
Vol 6 (3) ◽  
pp. 230-236
Author(s):  
Shinji Mitsuta ◽  
◽  
Kazuto Seto ◽  
Hiroyuki Ito ◽  
Akio Nagamatsu ◽  
...  
Keyword(s):  
Vibration Control ◽  
Motion Control ◽  
Control Method ◽  
Flexible Structures ◽  
Sine Wave ◽  
Flexible Structure ◽  
Control Force ◽  
Control Effect ◽  
Dynamic Absorber ◽  
Servo Controller

Recently, the necessity for making machines weighing less and operating at high speeds has increased. This paper is concerned with vibration and motion control by a control system which combines a servo controller and a hybrid dynamic absorber. In our method, vibration control and motion control are designed independently. First, the dynamics of a tower structure and a servo motor are modeled. Then, it is shown experimentally that although vibration control by the servo controller alone causes instability due to nonlinear elements such as friction or rattle, the hybrid dynamic absorber does not easily cause this sort of instability. On the comparison of vibration control effect and control force, the hybrid dynamic absorber requires less force. Finally, to know the effect of the new method, we evaluated the motions (triangular wave and sine wave) of the flexible structure. The effectiveness of this vibration and motion control method for the flexible structure was demonstrated by simulations and experiments.

An Influence Analysis of Second-Order Effect to the Vibration Control of Piezoelectric Beam by the Spline Finite Point Method

2012 ◽  
Vol 166-169 ◽  
pp. 3124-3130 ◽  
Author(s):  
Shuang Bei Li ◽  
Lin Jie Jiang ◽  
Chun Xia Gu ◽  
Rong Qin
Keyword(s):  
Control Theory ◽  
Vibration Control ◽  
Axial Force ◽  
Natural Frequencies ◽  
Order Effect ◽  
Second Order ◽  
Modal Control ◽  
Finite Point ◽  
Axial Forces ◽  
Piezoelectric Beam

The field functions of the spline finite point (SFP) method were constructed by the linear combination of B-spline basis function, and the higher-precision results would be obtained with less discrete nodes by the SFP method. In this paper, based on Reddy's third order beam theory, a motion equation was developed by the SFP method to analyze the first five natural frequencies of piezoelectric laminated beam under different axial forces. The influence of second-order effect caused by the axial force on vibration control was discussed based on the modal control theory and the Linear Quadratic Regulator (LQR) optimal control method. It can be concluded that the SFP method is suitable for the dynamic analysis of piezoelectric beam which needs less computational cost and has high accuracy. The vibration of the structure can be effectively inhibited by the LQR method and modal control theory. And the axial force has significant impact on the natural frequencies and control voltage of piezoelectric beam.

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