Design and Optimization of Multiple Single-DOF Tuned Mass Dampers Based on Flexure Design Theory

2018 ◽  
Author(s):  
Wenshuo Ma ◽  
Yiqing Yang ◽  
Jingjun Yu
Keyword(s):  
Design Theory ◽  
Dynamic Performance ◽  
Maximum Amplitude ◽  
Single Mode ◽  
Primary System ◽  
Tuned Mass Dampers ◽  
Precision Engineering ◽  
Element Analysis ◽  
Design And Optimization ◽  
Stiffness And Damping

Vibration is an undesirable phenomenon in engineering, and its avoidance has received considerable attention, especially for the cases of precision engineering. Since the dynamic performance of precision mechanisms are most likely to be restricted by their 1st modes, multiple single degree of freedom (SDOF) tuned mass dampers (TMDs) are designed to suppress a translational moving platform with single mode. The TMDs are designed with optimal stiffness and damping ratios, which are acquired by numerical optimization using minimax algorithm. Each SDOF TMD is implemented via the graphical approach and modeled by substructure dynamic modeling techniques. Results of finite element analysis (FEA) show that the maximum amplitude of frequency response function (FRF) of the primary system can be damped to 89.14% when N is 3, which validates the vibration mitigation by employing the designed TMDs. Furthermore, the proposed design routine provides a guidance for implementation of multiple SDOF TMDs.

Effective and Robust Vibration Control Using Series Multiple Tuned-Mass Dampers

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Lei Zuo
Keyword(s):  
Total Mass ◽  
Primary System ◽  
Vibration Absorbers ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
In Series ◽  
New Type ◽  
Parameter Variance ◽  
Stiffness And Damping ◽  
Optimal Series

Various types of tuned-mass dampers (TMDs), or dynamic vibration absorbers, have been proposed in literature, including the classic TMD, (parallel) multiple TMDs, multidegree-of-freedom (DOF) TMD, and three-element TMD. In this paper we study the characteristics and optimization of a new type of TMD system, in which multiple absorbers are connected to the primary system in series. Decentralized H2 and H∞ control methods are adopted to optimize the parameters of spring stiffness and damping coefficients for random and harmonic vibration. It is found that series multiple TMDs are more effective and robust than all the other types of TMDs of the same mass ratio. The series two TMDs of total mass ratio of 5% can appear to have 31–66% more mass than the classical TMD, and it can perform better than the optimal parallel ten TMDs of the same total mass ratio. The series TMDs are also less sensitive to the parameter variance of the primary system than other TMD(s). Unlike in the parallel multiple TMDs where at the optimum the absorber mass is almost equally distributed, in the optimal series TMDs the mass of the first absorber is generally much larger than the second one. Similar to the 2DOF TMD, the optimal series two TMDs also have zero damping in one of its two connections, and further increased effectiveness can be obtained if a negative dashpot is allowed. The optimal performance and parameters of series two TMDs are obtained and presented in a form of ready-to-use design charts.

scholarly journals Design and optimization of main reducer based on Baja racing

2021 ◽  
Vol 260 ◽  
pp. 03015
Author(s):  
Taiyu Ning ◽  
Chao He ◽  
Jifei Chen ◽  
Xueyuan Liu ◽  
Wengang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Reliability ◽  
Dynamic Performance ◽  
3D Models ◽  
Transmission Ratio ◽  
Main Function ◽  
Element Analysis ◽  
Ratio Distribution ◽  
Design And Optimization ◽  
Main Component

The main reducer is the main component of the whole vehicle, and its main function is to realize deceleration and torque increase. For Baha racing car, in order to improve the dynamic performance of the whole car, the main reducer is designed from the aspects of layout, transmission ratio distribution, shift mode, overall size and shell structure. Calculate the transmission ratio range of reducer according to the performance parameters of transmission parts, and verify the rationality of transmission ratio; Then determine the parameters of gear according to the transmission ratio and related parameters, and finally design the parameters of gear according to the transmission ratio and related parameters, and finally design the parameters of other parts of reducer. Based on the determined parameters, 3D modeling software UG is used to build 3D models of various parts of the reducer, and finite element analysis software ANSYS is used to simulate and analyze the parts to check whether the comprehensive mechanical properties meet the requirements. In this paper, the design of the main reducer realizes the comprehensive design of small size, light weight, reasonable transmission ratio distribution, high reliability, shifting gears during driving, and the comprehensive mechanical properties also meet the requirements.

Characteristics and Optimization of Series Multiple Tuned-Mass Dampers

2007 ◽  
Author(s):  
Lei Zuo
Keyword(s):  
Total Mass ◽  
Vibration Suppression ◽  
Primary System ◽  
Mass Ratio ◽  
Dynamic Vibration Absorber ◽  
Tuned Mass Dampers ◽  
In Series ◽  
New Type ◽  
Stiffness And Damping ◽  
Better Than

Tuned-mass damper (TMD), or dynamic vibration absorber (DVA), is a very practical and effective device for vibration suppression. Various types of tuned-mass dampers have been proposed in literature, including the classic TMD, (parallel) multiple TMDs, multi-degree-of-freedom (DOF) TMD, and three-element TMD. In this paper we study the characteristics and optimization of a new type of TMD system, in which multiple absorbers are connected to the primary system in series. Structured H2 and H∞ control methods are adopted to optimize the parameters of spring stiffness and damping coefficients for random and harmonic vibration. It is found that series multiple TMDs are more effective and robust than all the other types of TMDs of the same mass ratio. The series two TMDs of total mass ratio 5% can appear to have 31%–66% more mass than the classical TMD, and it can perform better than parallel ten TMDs of the same total mass ratio. The series TMDs are also less sensitive to the parameter changes of the primary system than other TMD(s). Unlike the parallel multiple TMDs, the optimal mass distribution among absorbers in series TMDs is far from the case of equal masses, but instead the first absorber mass is much larger than the second one. Similar to the two-DOF TMD, the optimal series two TMDs also have zero damping in one of its two connections and further increased effectiveness can be obtained if negative dashpot is allowed.

Design and Optimization of a Spatial Hybrid Motion System

2010 ◽  
Author(s):  
P. R. Ouyang ◽  
Steven Cargnello
Keyword(s):  
Optimization Design ◽  
Design Principle ◽  
Compliant Mechanism ◽  
Dynamic Performance ◽  
Parallel Architecture ◽  
Element Analysis ◽  
Design And Optimization ◽  
Motion System ◽  
Micro Motion ◽  
Hybrid Motion

In this paper, a spatial hybrid motion system is developed that integrates two types of motions through one compliant mechanism: a macro motion driven by a DC servomotor and a micro motion driven by a PZT actuator. A unique feature of the developed hybrid motion system is the elimination of interaction between the macro motion and micro motion. Three issues are addressed in this study: (1) the design principle and implementation of the hybrid motion system; (2) the kinematic analysis and dynamic analysis; and (3) the optimization design of the hybrid motion system. For the micro motion, the five-bar topology of a mechanical amplifier is used to increase amplifying ratio and improve dynamic performance of the system. Finite element analysis results verify the design principle of the parallel architecture for the hybrid motion system.

scholarly journals EXPERIMENTAL ANALYSIS OF THE VISCOUS TUNED MASS DAMPER FOR THE ATTENUATION OF STRUCTURAL RESPONSES

2021 ◽  
Vol 83 (6) ◽  
pp. 125-139
Author(s):  
Afham Zulhusmi Ahmad ◽  
Aminudin Abu ◽  
Lee Kee Quen ◽  
Nor’azizi Othman ◽  
Faridah Che In
Keyword(s):  
Experimental Analysis ◽  
Thermoplastic Polyurethane ◽  
Single Mode ◽  
Shaking Table ◽  
Primary System ◽  
Structural System ◽  
Tuned Mass Dampers ◽  
Mass Damper ◽  
Structural Responses ◽  
Mode Vibration

This paper presents a systematic experimental investigation on the performance of a Multiple Tuned Mass Dampers (MTMDs) attached to a structural system under dynamic load excitation. A Modal Experimental Analysis (EMA) of a three-story structural frame equipped with a viscous damper system was carried out through a series of shaking table tests to evaluate the performance and verify the analysis approach. Each of the TMDs consists of a mass attached to a structural floor via Thermoplastic Polyurethane (TPU) viscous bearing. Initially, the TMD was designed solely to control single mode vibration and then the mechanism is extended for the application of controlling multimode responses. The experiment demonstrated that the proposed viscous dampers exhibit good performance in reducing the response of structures under dynamic loads, and able to control both fundamental and higher vibration modes of a Multiple Degree of Freedom (MDOF) primary system effectively. It was also evident that the attachment of the air dashpot dampers to each of TMDs lead to better efficiency on controlling the amplification of the damper mass and significantly contribute to better structural modal tuning.

Vibration characteristics of island-bridge structure on porous PDMS substrates for stretchable electronics

2021 ◽  
pp. 1-18
Author(s):  
Xin Song ◽  
Zuguang Bian ◽  
Xiaoliang Zhou ◽  
Zhuye Huang
Keyword(s):  
Analytical Model ◽  
Mechanical Design ◽  
Dynamic Performance ◽  
Structure Design ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Stretchable Electronics ◽  
Bridge Structure ◽  
Element Analysis ◽  
Design And Optimization

Abstract Stretchable electronics employing island-bridge structure design can achieve controllable and reversible stretchability. The use of a porous substrate, which provides excellent breathability for wearable devices bonded to skin, not only satisfies this static superiority but also has a profound impact on the dynamic performance of the stretchable electronics. In this paper, the vibration characteristics of the island-bridge structure based on porous polydimethylsiloxane (p-PDMS) substrates are studied by utilizing an analytical model, which takes account of geometric nonlinearity due to mid-plane stretching, buckling configuration, elastic boundary conditions considering the p-PDMS substrates and the mass of the island. In numerical examples, the accuracy of the analytical model is first verified by finite element analysis (FEA). After that, we investigate the effects of some primary factors, i.e. the prestrain of the substrate, spring stiffnesses at the ends of the interconnect, porosity and thickness of the substrate, and the mass of the island, on the natural frequencies and vibration mode shapes of the island-bridge structure. Results show that the vibration characteristics of the island-bridge structure can be tuned conveniently by adjusting the porosity of the substrate and the mass of the island, which are expected to be helpful to mechanical design and optimization of stretchable electronics in complex noise environments.

Optimization of the Individual Stiffness and Damping Parameters in Multiple-Tuned-Mass-Damper Systems

2005 ◽  
Vol 127 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Lei Zuo ◽  
Samir A. Nayfeh
Keyword(s):  
Parameter Optimization ◽  
Substantial Improvement ◽  
Design Parameters ◽  
Feedback Gain ◽  
Primary System ◽  
Tuned Mass Dampers ◽  
H2 Control ◽  
Damping Coefficients ◽  
The Individual ◽  
Stiffness And Damping

The characteristics of multiple tuned-mass-dampers (MTMDs) attached to a single-degree-of-freedom primary system have been examined by many researchers. Several papers have included some parameter optimization, all based on restrictive assumptions. In this paper, we propose an efficient numerical algorithm to directly optimize the stiffness and damping of each of the tuned-mass dampers (TMDs) in such a system. We formulate the parameter optimization as a decentralized H2 control problem where the block-diagonal feedback gain matrix is composed of the stiffness and damping coefficients of the TMDs. The gradient of the root-mean-square response with respect to the design parameters is evaluated explicitly, and the optimization can be carried out efficiently. The effects of the mass distribution, number of dampers, total mass ratio, and uncertainties in system parameters are studied. Numerical results indicate that the optimal designs have neither uniformly spaced tuning frequencies nor identical damping coefficients, and that optimization of the individual parameters in the MTMD system yields a substantial improvement in performance. We also find that the distribution of mass among the TMDs has little impact on the performance of the system provided that the stiffness and damping can be individually optimized.

scholarly journals Coulomb-actuated microbeams revisited: experimental and numerical modal decomposition of the saddle-node bifurcation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Anton Melnikov ◽  
Hermann A. G. Schenk ◽  
Jorge M. Monsalve ◽  
Franziska Wall ◽  
Michael Stolz ◽  
...  
Keyword(s):  
Finite Element ◽  
Microelectromechanical Systems ◽  
Dynamic Range ◽  
Dynamic Performance ◽  
Major Step ◽  
Element Analysis ◽  
Electrostatic Actuators ◽  
Voltage Range ◽  
Drive Voltage ◽  
Depth Analysis

AbstractElectrostatic micromechanical actuators have numerous applications in science and technology. In many applications, they are operated in a narrow frequency range close to resonance and at a drive voltage of low variation. Recently, new applications, such as microelectromechanical systems (MEMS) microspeakers (µSpeakers), have emerged that require operation over a wide frequency and dynamic range. Simulating the dynamic performance under such circumstances is still highly cumbersome. State-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary information about unstable equilibrium states accordingly. Convincing lumped-parameter models amenable to direct physical interpretation are missing. This inhibits the indispensable in-depth analysis of the dynamic stability of such systems. In this paper, we take a major step towards mending the situation. By combining the finite element method (FEM) with an arc-length solver, we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams. A subsequent modal analysis then shows that within very narrow error margins, it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage range. An experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing precision. This enables modeling the system using a single spatial degree of freedom.

Multimodal pizza-shaped piezoelectric vibration-based energy harvesters

2021 ◽  
pp. 1045389X2110069
Author(s):  
Virgilio J Caetano ◽  
Marcelo A Savi
Keyword(s):  
Energy Harvesting ◽  
Frequency Spectrum ◽  
Optimization Procedure ◽  
Single Mode ◽  
Ambient Vibration ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Energy harvesting from ambient vibration through piezoelectric devices has received a lot of attention in recent years from both academia and industry. One of the main challenges is to develop devices capable of adapting to diverse sources of environmental excitation, being able to efficiently operate over a broadband frequency spectrum. This work proposes a novel multimodal design of a piezoelectric energy harvesting system to harness energy from a wideband ambient vibration source. Circular-shaped and pizza-shaped designs are employed as candidates for the device, comparing their performance with classical beam-shaped devices. Finite element analysis is employed to model system dynamics using ANSYS Workbench. An optimization procedure is applied to the system aiming to seek a configuration that can extract energy from a broader frequency spectrum and maximize its output power. A comparative analysis with conventional energy harvesting systems is performed. Numerical simulations are carried out to investigate the harvester performances under harmonic and random excitations. Results show that the proposed multimodal harvester has potential to harness energy from broadband ambient vibration sources presenting performance advantages in comparison to conventional single-mode energy harvesters.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

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