Vibration Control of Vehicles With Flexible Structure Using Optimum Tuned-Mass Dampers

2010 ◽  
Author(s):  
Avesta Goodarzi ◽  
Neda Pandarathil ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Vibration Suppression ◽  
Ride Comfort ◽  
Optimization Method ◽  
Design Parameters ◽  
Future Research ◽  
Flexible Structure ◽  
Vibration Absorbers ◽  
Tuned Mass Dampers ◽  
Dynamic Vibration Absorbers

Vibrations resulting from flexural motion of elastic vehicle structures are of particular significance to the ride comfort of vehicles. Tuned-mass dampers (dynamic vibration absorbers) are among the most commonly used devices for vibration suppression. In this paper the application of optimum tuned-mass dampers is addressed, that can be used to reduce annoying flexibility originated vibration. A newly developed flexible model is representing the vehicle with eight-degree-of-freedom (8-DOF) with a systematic approach to select the optimum locations of the absorbers. Using passive vibration absorbers and applying the min-max optimization method to find the optimum values of the design parameters. Simulation results for a case study bus with flexible structure confirm the strength of the proposed design. For those who wish to pursue future research on this subject few suggestions are given.

Optimal Design and Experimental Study of a Multidynamic Vibration Absorber for Multifrequency Excitation

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Xi Wang ◽  
Bintang Yang ◽  
Hu Yu
Keyword(s):  
Vibration Suppression ◽  
Optimization Method ◽  
Equal Mass ◽  
Vibration Absorber ◽  
Primary System ◽  
Vibration Absorbers ◽  
Optimal Damping ◽  
Manufacturing Errors ◽  
Limited Frequency ◽  
Dynamic Vibration Absorbers

The inevitable manufacturing errors of rotational machineries cause vibration of multifrequency. This paper presents a multidynamic vibration absorber (MDVA) to suppress the vibration of multifrequency. The MDVA consists of two parts, and each part includes three dynamic vibration absorbers (DVAs) with equal mass but different stiffness values. In order to improve the robustness of the system, an optimization method to obtain the optimal damping values of each DVA is proposed based on dynamic response. The objective function of optimization aims to flatten the frequency response of the primary system with the changeable excitation and reduce the vibration level in a limited frequency bandwidth. The multifrequency vibration suppression is experimentally verified. To achieve the optimal damping values, the magnetic dampers are applied in the tests. The experimental results indicate that the sensitivity of the system is reduced and the robustness of the system is enhanced, which are coincident with the simulations.

Free Parameter Optimization of DTMDs Based on Improved Hybrid Genetic-Simulated Annealing Algorithm

2020 ◽  
Vol 20 (03) ◽  
pp. 2050031
Author(s):  
Qiang Han ◽  
Xuan Zhang ◽  
Kun Xu ◽  
Xiuli Du
Keyword(s):  
Simulated Annealing ◽  
Parameter Optimization ◽  
Free Parameter ◽  
Simulated Annealing Algorithm ◽  
Optimization Method ◽  
Design Parameters ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Genetic Simulated Annealing Algorithm ◽  
Annealing Algorithm

The optimum design of distributed tuned mass dampers (DTMDs) is normally based on predefined restrictions, such as the location and/or mass ratio of the tuned mass dampers (TMDs). To further improve the control performance, a free parameter optimization method (FPOM) is proposed. This method only restricts the total mass of the DTMDs system and takes the installation position, mass ratio, stiffness and damping of each TMD as parameters to be optimized. An improved hybrid genetic-simulated annealing algorithm (IHGSA) is adopted to find the optimum values of the design parameters. This algorithm can solve the non-convexity and multimodality problems of the objective function and is quite effective in dealing with the large amount of computations in the free parameter optimization. A numerical benchmark model is adopted to compare the control efficiency of FPOM with conventional control scenarios, such as single TMD, multiple TMDs and DTMDs optimized through conventional methods. The results show that the DTMDs system optimized by using FPOM is superior to the other control scenarios for the same value of mass ratio.

Research on Optimization of Ground-Coupled Heat Pump Systems under Specific Constraint Conditions

2014 ◽  
Vol 953-954 ◽  
pp. 673-679
Author(s):  
Yang Yang Wang ◽  
Ping Fang Hu ◽  
Fei Lei ◽  
Na Zhu ◽  
Tian Hua Wu ◽  
...  
Keyword(s):  
Heat Pump ◽  
Optimization Problem ◽  
Design Method ◽  
Optimization Method ◽  
Simulation Software ◽  
Design Parameters ◽  
Decision Variable ◽  
Economic Optimization ◽  
Ground Coupled Heat Pump

A design method for ground-coupled heat pump (GCHP) systems with specific constraint conditions is proposed. The total borehole number, borehole depth, borehole space and average velocity of fluid in the U-tube are considered as variables in the optimization problem. The optimization problem of four variables is transformed into that of single decision variable. A case study, which includes different schemes for designing GCHP systems of an office building and the corresponding economic analysis, is performed with the aid of simulation software. The result shows that optimal design parameters could be found in an economic optimization problem with specific constraint conditions. Additionally, design parameters may have a notable influence on the energy consumption of circulating pumps. The optimization method in this paper could be utilized by engineering designers for reference.

Mixed H2/H∞ guaranteed cost control for high speed elevator active guide shoe with parametric uncertainties

2020 ◽  
Vol 21 (5) ◽  
pp. 502
Author(s):  
Chen Chen ◽  
Ruijun Zhang ◽  
Qing Zhang ◽  
Lixin Liu
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
State Feedback ◽  
Vibration Suppression ◽  
Ride Comfort ◽  
Optimization Method ◽  
State Feedback Control ◽  
Guide Rail ◽  
Vibration Displacement ◽  
Guaranteed Cost

Aiming at the phenomenon that the elevator car system generates horizontal vibration due to the unevenness of the guide rail and the guide shoe modeling uncertainty caused by friction, wear and spring aging between the rolling guide shoe and the guide rail, a mixed H2/H∞ optimal guaranteed cost state feedback control strategy is proposed. Firstly, as the high-speed elevator car system always exist the phenomenon of stiffness and damping uncertainty in the guide shoe, the LFT method is adopted to construct the state space equation of the car system with parameter uncertainty. Secondly, considering the performance indexes of horizontal acceleration at the center of the car floor and the guide shoe vibration displacement system, an optimal guaranteed performance state feedback controller is designed based on the linear convex optimization method, which to minimize H2 performance index and achieve the specified H∞ performance level. Thirdly, the free matrix is introduced to reduce the conservatism of the controller. Finally, by comparing the simulation results with other control methods under the same conditions, it is verified that the control strategy can make the car system have better vibration suppression ability, and can significantly improve the ride comfort of the elevator.

Closed-Form Exact Solution to H∞ Optimization of Dynamic Vibration Absorbers (Application to Different Transfer Functions and Damping Systems)

2003 ◽  
Vol 125 (3) ◽  
pp. 398-405 ◽  
Author(s):  
Toshihiko Asami ◽  
Osamu Nishihara
Keyword(s):  
Exact Solutions ◽  
Closed Form ◽  
Optimization Problem ◽  
Vibration Suppression ◽  
Transfer Functions ◽  
New Method ◽  
Algebraic Solution ◽  
Vibration Absorbers ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers

H ∞ optimization of the dynamic vibration absorbers is a classical optimization problem, and has been already solved more than 50 years ago. It is a well-known solution, but we know this solution is only an approximate one. Recently, one of the authors has proposed a new method for attaining the H∞ optimization of the absorber in linear systems. The new method enables us to obtain the exact algebraic solution of the H∞ optimization problem of the absorber. In this paper, we first apply this method to the design optimization of a viscous damped (Voigt type) absorber and a hysteretic damped absorber attached to undamped primary systems. For each absorber, six different transfer functions are taken here as performance indices to vibration suppression or isolation. As a result, we found the closed-form exact solutions to all transfer functions. The solutions obtained here are then compared with those of the approximate ones. Finally, we present the closed-form exact solutions to the hysteretic damped absorber attached to damped primary systems.

Dynamic Vibration Absorbers That Have Increased Effectiveness

1974 ◽  
Vol 96 (3) ◽  
pp. 940-945 ◽  
Author(s):  
J. C. Snowdon
Keyword(s):  
Complete Information ◽  
Graphical Form ◽  
Design Parameters ◽  
Vibration Absorbers ◽  
Large Magnitude ◽  
Mass System ◽  
Wide Range ◽  
Dynamic Vibration Absorbers ◽  
Dynamic Absorber ◽  
First Time

The effectiveness of a three-element dynamic absorber and of dual dynamic absorbers in reducing the transmissibility across a simple spring-mass system at resonance has been investigated and shown to be considerably greater than that of the conventional dynamic absorber. From the complete information provided, much in graphical form, it is possible to design and to estimate the performance of both the three-element and the dual dynamic absorbers for a wide range of absorber masses. Utilizing design parameters that have been determined and specified here for the first time, it is shown 1) that the three-element absorber can be more effective than a conventional absorber of twice its mass, and 2) that by use of dual absorbers, it is possible to obtain a significant trough in transmissibility while avoiding the two resonant peaks of large magnitude that are normally introduced at neighboring frequencies. The three-element absorber requires no increase, and the dual absorbers require only a modest increase in mass beyond that of the conventional dynamic absorber.

Optimal Design of Double-Mass Dynamic Vibration Absorbers Minimizing the Mobility Transfer Function

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Toshihiko Asami ◽  
Yoshito Mizukawa ◽  
Tomohiko Ise
Keyword(s):  
Transfer Function ◽  
Vibration Suppression ◽  
Optimal Solution ◽  
Algebraic Solution ◽  
Primary System ◽  
Vibration Absorbers ◽  
Dynamic Vibration ◽  
Double Mass ◽  
Dynamic Vibration Absorbers ◽  
The Absolute

Although the vibration suppression effects of precisely adjusted dynamic vibration absorbers (DVAs) are well known, multimass DVAs have recently been studied with the aim of further improving their performance and avoiding performance deterioration due to changes in their system parameters. One of the present authors has previously reported a solution that provides the optimal tuning and damping conditions of the double-mass DVA and has demonstrated that it achieves better performance than the conventional single-mass DVA. The evaluation index of the performance used in that study was the minimization of the compliance transfer function. This evaluation function has the objective of minimizing the absolute displacement response of the primary system. However, it is important to suppress the absolute velocity response of the primary system to reduce the noise generated by the machine or structure. Therefore, in the present study, the optimal solutions for DVAs were obtained by minimizing the mobility transfer function rather than the compliance transfer function. As in previous investigations, three optimization criteria were tested: the H∞ optimization, H2 optimization, and stability maximization criteria. In this study, an exact algebraic solution to the H∞ optimization of the series-type double-mass DVA was successfully derived. In addition, it was demonstrated that the optimal solution obtained by minimizing the mobility transfer function differs significantly at some points from that minimizing the compliance transfer function published in the previous report.

scholarly journals Optimal design of tuned mass dampers through differential evolution method for reducing the dynamic response of structures subjected to earthquake loads

ENTRAMADO ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 244-254
Author(s):  
Daniel Alejandro Caicedo-Díaz ◽  
Luis Augusto Lara-Valencia ◽  
Yamile Valencia-González
Keyword(s):  
Optimal Design ◽  
Dynamic Response ◽  
Differential Evolution ◽  
Selection Process ◽  
Design Parameters ◽  
Tuned Mass Dampers ◽  
Ground Acceleration ◽  
Peak Displacement ◽  
Earthquake Loads

This paper introduces a methodology for the optimal design of passive Tuned Mass Dampers (TMDs) to control the dynamic response of buildings subjected to earthquake loads. The selection process of the optimal design parameters is carried out through a metaheuristic approach based on differential evolution (DE) which is a fast, efficient, and precise technique that does not require high computational efforts. The algorithm is aimed to reduce the maximum horizontal peak displacement of the structure and the root mean square (RMS) response of displacements as well. Furthermore, four more objective functions derived from multiple weighted linear combinations of the two previously mentioned parameters are also studied to obtain the most efficient TMD design configuration. A parallel process based on an exhaustive search (ES) with precision to 2 decimal positions is used to validate the optimization methodology based on DE. The proposed methodology is then applied to a 32-story case-study derived from an actual building structure and subjected to different ground acceleration registers. The best dynamic performance of the building is observed when the greatest weight is given to the RMS response of displacement in the optimization process. Finally, the numerical results reveal that the proposed methodology based on DE is effective in finding the optimal TMD design configuration by reducing the maximum floor displacement up to 4% and RMS values of displacement of up to 52% in the case-study building.

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