Study on the performance of a gear‐driven rotation‐amplified rubber viscoelastic damper and its vibration control of a frame structure

A new CNC lathe with a pipe frame bed has been developed. One requested improvement for machine tools is their downsizing by minimizing the number of mechanical parts. Some researchers aim to construct a desktop factory. This trend has been attracting a lot of attention lately in the industrial field. When a machine tool bed is designed using castings and/or welded steel plate structures to comply with this request, it is difficult to ensure space for chip evacuation because of the space limitations of solid body components. This led us to develop another type of structure for machine tools. A pipe frame bed has the ability to solve this problem. As represented by bridge trusses and flexible space structures, truss structures are traditional and fundamental in their design. This structure is expected to have enough space between the truss bars to solve the space problem. However, rigidity is the most significant issue for machine tools. Therefore, the desired rigidity is ensured by the use of diagonal braces. Based on this design concept, a CNC lathe whose frame consists of pipes, joints, and diagonal braces has been developed with enough rigidity and space utility for chip evacuation. From the viewpoint of machine tool usage, the rigidity and stable dynamic characteristics of the structure must be obtained. Then, real-time vibration control theory is applied to the relative displacement between the tool post and the spindle. Active vibration control is used to suppress specific relative vibration modes. In this paper, the effects of vibration control are evaluated by comparing the relative vibratory motion between the tool post and the spindle. Over 50% suppression has been achieved by applying vibration control to the target vibration mode. Additionally, using this control, the machined profile has been improved, and the roundness and harmonic analysis of the workpiece showed over 30% improvement.

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Study on the influence of structural nonlinearity on the performance of multiunit impact damper

Journal of Vibration and Control ◽

10.1177/1077546320925620 ◽

2020 ◽

pp. 107754632092562

Author(s):

Zheng Lu ◽

Naiyin Ma ◽

Hengrui Zhang

Keyword(s):

Vibration Control ◽

Damping Ratio ◽

Mean Square Displacement ◽

Random Excitation ◽

Frame Structure ◽

Control Effect ◽

Momentum Exchange ◽

Impact Damper ◽

Structural Nonlinearity ◽

Steel Frame Structure

In this article, the vibration control effect of the multiunit impact damper under stationary random excitation and seismic excitation is studied, based on both the elastic and nonlinear benchmark structures. The benchmark structure is a nonlinear steel frame structure, which can calculate the nonlinear response by considering the material nonlinearity at the ends of the beam and column. To analyze the influence of various system parameters on the performance of the multiunit impact damper, such as the number of units, mass ratio, damping ratio, and gap clearance, a great number of parameter studies are carried out. In addition, the control effects of the multiunit impact damper on elastic and nonlinear structures are compared to analyze the influence of structural nonlinearity on the performance of the multiunit impact damper. The results show that a lightweight multiunit impact damper with reasonable parameters can significantly reduce the root mean square displacement response of the benchmark structure. Furthermore, the structural nonlinearity will lead to a decrease in the vibration control performance of the multiunit impact damper. The reasons for this phenomenon are that the effective momentum exchange and energy dissipation of the multiunit impact damper will decrease when the benchmark structure responds in a nonlinear state.

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Vibration control of a frame structure using electro-rheological fluid mounts

International Journal of Mechanical Sciences ◽

10.1016/s0020-7403(02)00172-8 ◽

2002 ◽

Vol 44 (10) ◽

pp. 2027-2045 ◽

Cited By ~ 29

Author(s):

Sung-Ryong Hong ◽

Seung-Bok Choi ◽

Moon-Shik Han

Keyword(s):

Vibration Control ◽

Frame Structure

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A Method of Optimum Installation of the Viscoelastic Damper on the Steel Frame Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.919-921.1027 ◽

2014 ◽

Vol 919-921 ◽

pp. 1027-1030

Author(s):

Li Ming Li ◽

Cheng Wei Huang ◽

Cheng Shen ◽

Yi Tian

Keyword(s):

Objective Function ◽

Analytical Method ◽

Optimization Method ◽

Steel Frame ◽

Frame Structure ◽

Viscoelastic Damper ◽

Performance Objective ◽

Practical Engineering ◽

Steel Frame Structure

The main purpose of optimum installation of the viscoelastic damper is to make the structure has a better seismic capacity.So we need find a reasonable objective function and a method to solve this function.This paper put forward a kind of optimization method based on the performance objective,explore suitability and feasibility of this method on the steel frame structure,and analyse the results compare with other optimization methods.The analytical method and the results has certain guiding significance for optimization of the viscoelastic damper in practical engineering.

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Modeling, Analyses, and Optimization of Planar Active Frame Structures Composed of Piezoelectric Beams

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455419501463 ◽

2019 ◽

Vol 19 (12) ◽

pp. 1950146 ◽

Cited By ~ 1

Author(s):

Ke Wu ◽

Houfei Fang ◽

Bingen Yang

Keyword(s):

Vibration Control ◽

Stiffness Matrix ◽

Shape Control ◽

Frame Structure ◽

Distributed Model ◽

Frame Structures ◽

Transverse Shear Strain ◽

Governing Equations ◽

Element Stiffness Matrix ◽

Ant Lion

Frame structures are widely used in engineering applications, especially in space structures. For special use such as shape and vibration control of such structures, piezoelectric patches are usually placed on the beam surfaces to form active frame structures. To perform shape control or vibration control tasks, modeling methods for the formed active frame structures need to be studied. This paper develops a new distributed model of an active frame structure composed of multilayer piezoelectric beam components. First, the governing equations of a beam, bonded with piezoelectric patches, are developed via the generalized Hamilton principle, by considering the transverse shear strain. Then, the analytical solutions of the governing equations and the generalized element stiffness matrix are derived through the distributed transfer function formulation. Finally, the analytical solution of the entire system is obtained by the technique for assembling element stiffness matrix. In numerical simulations, buckling and vibration of an active frame structure are both studied. In addition, a novel Improved Ant Lion algorithm is proposed for optimal design of the frame structures. The optimization examples confirm that the proposed algorithm is more efficient than other existing popular algorithms such as Genetic Algorithm (GA) and Ant Lion Optimization (ALO) algorithm.

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