scholarly journals Optimum Design of PID Controlled Active Tuned Mass Damper via Modified Harmony Search

2020 ◽  
Vol 10 (8) ◽  
pp. 2976 ◽  
Author(s):  
Aylin Ece Kayabekir ◽  
Gebrail Bekdaş ◽  
Sinan Melih Nigdeli ◽  
Zong Woo Geem
Keyword(s):  
Block Diagram ◽  
Harmony Search ◽  
Pid Controllers ◽  
Tuned Mass Dampers ◽  
Maximum Displacement ◽  
Capacity Limit ◽  
Design Variables ◽  
Mass Damper ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping

In this study, the music-inspired Harmony Search (HS) algorithm is modified for the optimization of active tuned mass dampers (ATMDs). The modification of HS includes the consideration of the best solution with a defined probability and updating of algorithm parameters such as harmony memory, considering rate and pitch adjusting rate. The design variables include all the mechanical properties of ATMD, such as the mass, stiffness and damping coefficient, and the active controller parameters of the proposed proportional–integral–derivative (PID) type controllers. In the optimization process, the analysis of an ATMD implemented structure is done using the generated Matlab Simulink block diagram. The PID controllers were optimized for velocity feedback control, and the objective of the optimization is the minimization of the top story displacement by using the limitation of the stroke capacity of ATMD. The optimum results are presented for different cases of the stroke capacity limit of ATMD. According to the results, the method is effective in reducing the maximum displacement of the structure by 53.71%, while a passive TMD can only reduce it by 31.22%.

An Optimum Tuning Application of Mass Dampers Considering Soil-Structure Interaction

2018 ◽  
pp. 44-73
Author(s):  
Gebrail Bekdaş ◽  
Sinan Melih Nigdeli
Keyword(s):  
Optimum Design ◽  
Soil Structure ◽  
Damping Ratio ◽  
Harmony Search ◽  
Soil Structure Interaction ◽  
Tuned Mass Dampers ◽  
Maximum Displacement ◽  
Structure Interaction ◽  
High Rise ◽  
Design Variables

In order to obtain a significant reduction for seismic responses of structures using tuned mass dampers (TMDs), optimization is a mandatory process. A music-inspired metaheuristic algorithm called harmony search is employed in the proposed method for optimum design of TMDs implemented on structures considering soil-structure interaction (SSI). The present approach considers time domain analyses conducted for several earthquake excitations. The optimum design variables, such as mass, period, and damping ratio of TMD are searched for an optimization objective (the maximum displacement of structure) and a design constraint (the maximum scaled stroke capacity of TMD). The proposed method was investigated with a 40-storey high-rise structure for different soil characteristics and the optimum results were compared with a previously developed metaheuristic approach. Results show that the proposed method is feasible and more effective than the compared method.

scholarly journals OPTIMIZATION OF TUNED MASS DAMPERS ATTACHED TO DAMPED STRUCTURES - MINIMIZATION OF MAXIMUM DISPLACEMENT AND ACCELERATION

2021 ◽  
Vol 30 ◽  
pp. 98-103
Author(s):  
Jan Štěpánek ◽  
Jiří Máca
Keyword(s):  
Frequency Response ◽  
Dynamic Behaviour ◽  
Harmonic Force ◽  
Tuned Mass Dampers ◽  
Maximum Displacement ◽  
Single Degree Of Freedom ◽  
Design And Optimization ◽  
Mass Damper ◽  
Proper Design ◽  
Structure Properties

A tuned mass damper is a device, which can be highly helpful while dealing with dynamic behaviour of structures. Its proper design is conditioned by knowledge of both loading and the structure properties. In many cases, the structure can be represented by single degree of freedom model, which simplifies the design and optimization of tuned mass dampers. Most of studies focus only on minimization of displacement of the main structure under harmonic force load, however, in many cases, different frequency response function would be more appropriate. This paper presents an extension of design formulas for the H∞ optimization of tuned mass dampers for damped structures and various frequency response functions.

scholarly journals Seismic Response Mitigation of Base-Isolated Buildings

2020 ◽  
Vol 10 (4) ◽  
pp. 1230 ◽  
Author(s):  
Mohammad Hamayoun Stanikzai ◽  
Said Elias ◽  
Rajesh Rupakhety
Keyword(s):  
Fragility Curves ◽  
Ground Motions ◽  
Equations Of Motion ◽  
Numerical Approach ◽  
Probability Of Failure ◽  
Base Shear ◽  
Tuned Mass Dampers ◽  
Maximum Displacement ◽  
Mass Damper ◽  
Shear Type

Earthquake response mitigation of a base-isolated (BI) building equipped with (i) a single tuned mass damper at the top of the building, (ii) multiple tuned mass dampers (MTMDs) at the top of the building, and (iii) MTMDs distributed on different floors of the building (d-MTMDs) is studied. The shear-type buildings are modeled by considering only one lateral degree of freedom (DOF) at the floor level. Numerical approach of Newmark’s integration is adopted for solving the coupled, governing differential equations of motion of 5- and 10-story BI buildings with and without TMD schemes. A set of 40 earthquake ground motions, scaled 80 times to get 3200 ground motions, is used to develop simplified fragility curves in terms of the isolator maximum displacement. Incremental dynamic analysis (IDA) is used to develop simplified fragility curves for the maximum target isolator displacement. It is found that TMDs are efficient in reducing the bearing displacement, top floor acceleration, and base shear of the BI buildings. In addition, it was noticed that TMDs are efficient in reducing the probability of failure of BI building. Further, it is found that the MTMDs placed at the top floor and d-MTMDs on different floors of BI buildings are more efficient in decreasing the probability of failure of the BI building when compared with STMD.

scholarly journals A parametric study of a tower controlled by a pendulum tuned mass damper: beam modelling

2018 ◽  
Vol 211 ◽  
pp. 14006
Author(s):  
Gino B. Colherinhas ◽  
Maura A. M. Shzu ◽  
Suzana M. Avila ◽  
Marcus V. G. de Morais
Keyword(s):  
Parametric Study ◽  
Structural Control ◽  
Structural Model ◽  
Tuned Mass Damper ◽  
Fe Model ◽  
Genetic Optimization ◽  
Mass Damper ◽  
Element Type ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping

This paper models a tower with a passive Pendulum Tuned Mass Damper (PTMD) with Finite Elements (FE) using the resources and capabilities of commercial software ANSYS. Although structural control of high and slender towers using PTMDs are widely studied in literature, it was not found yet studies modelling the PTMD with ANSYS. This FE model is called by a routine coded in MATLAB to find the relation between the mass, length, stiffness, and damping coefficient of the pendulum in function of the high vibration amplitudes at the top of the tower (defined as a beam element type). This parametric study of the dynamic behaviour of the PTMD + FE beam structural model is analysed and its results are compared to a genetic optimization developed in other researches to find the best pendulum parameters.

Reduction of Jerk Through Optimization of a Knee Assistive Device Designed Using Four-Bar Controlled Compliance Actuator

2018 ◽  
Author(s):  
Saikat Sahoo ◽  
Aditya Jain ◽  
Dilip Kumar Pratihar
Keyword(s):  
Knee Joint ◽  
Stance Phase ◽  
Reaction Force ◽  
Swing Phase ◽  
Damping Coefficient ◽  
Assistive Device ◽  
Spring Stiffness ◽  
Design Variables ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping

Two major responsibilities are taken by a knee joint during level ground walking of a human being. At stance phase, knee joint is locked in order to provide stability against ground reaction force, and in swing phase, knee flexes for ground clearance of the foot. In this study, a four-bar controlled compliance actuator (FCCA) has been configured for assisting the knee joint during walking. The main focus of FCCA design is the reduction of required mechanical power through a compliance actuation strategy and amplification of motor power. The proposed design consists of two linear spring-damper systems, out of which, one controls the locking of knee during stance phase and another takes care of knee flexion at swing phase. Without a proper selection of stiffness and damping coefficient for both the springs, the knee may be subjected to jerk during flexion, which may give rise to discomfort to the user and consequently, he/she may fall during walking. This study aims to ensure smooth knee operation in both stance phase as well as swing phase by assigning the proper spring stiffness and damping coefficient for both the springs. The responsibility is given to a non-traditional optimization tool, namely particle swarm optimization (PSO). The optimization is carried out using a co-simulation approach between Matlab and ADAMS. The aim of PSO (run in Matlab) is to minimize both the frequency as well as amplitude of the jerk by finding a suitable set of design variables, that is, spring stiffness and damping coefficient of two spring-damper systems.

EVALUATION OF MULTIPLE DUAL TUNED MASS DAMPERS FOR STRUCTURES UNDER HARMONIC GROUND ACCELERATION

2006 ◽  
Vol 06 (01) ◽  
pp. 59-75 ◽  
Author(s):  
B. K. HAN ◽  
C. X. LI
Keyword(s):  
Natural Frequencies ◽  
Type I ◽  
Arbitrary Integer ◽  
Tuned Mass Dampers ◽  
Ground Acceleration ◽  
Parametric Studies ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
First Time ◽  
Dynamic Magnification Factor

The multiple dual tuned mass dampers, referred to as the MDTMD, consisting of several units of dual tuned mass dampers (DTMD) are proposed for the first time herein, aimed at the effectiveness and robustness of the system for suppressing the undesirable vibrations of structures under the ground acceleration. The total number of dampers can be arbitrary and their natural frequencies are uniformly distributed. Ten typical types of the MDTMD can be devised by varying the system parameters. Employing the criteria chosen for optimum searching, parametric studies were carried out to evaluate the performance of the MDTMD of Type I-1 for its convenience in manufacturing, in which the larger mass blocks (LMBs) are assumed to have identical stiffness, but unequal masses, and the smaller mass blocks (SMBs) have identical stiffness and damping coefficient, but unequal masses and damping ratios. By adopting the maximum dynamic magnification factor (DMF) for each LMB and SMB used in estimating the stroke, an evaluation is also made for the stroke of the MDTMD. The numerical results indicate that the MDTMD (I-1) can provide better effectiveness and higher robustness in comparison with the dual tuned mass dampers (DTMD) and other MTMD systems of similar complexities. However, the stroke of the MDTMD is greater than that of the DTMD and the stroke of each SMB in the MDTMD is larger than that of the mass blocks (MBs) in the arbitrary integer and odd number based MTMD.

Effectiveness of Location and Number of Multiple Tuned Mass Damper for Seismic Structures

2020 ◽  
Vol 9 (6) ◽  
pp. 780-783
Keyword(s):  
Seismic Response ◽  
Software Tool ◽  
Tuned Mass Damper ◽  
Structure Study ◽  
Structural Performance ◽  
Mass Ratio ◽  
Tuned Mass Dampers ◽  
Maximum Reduction ◽  
Mass Damper ◽  
Earthquake Data

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.

Design of a Damper for a Suspension System via Evolutive Optimization

2013 ◽  
Author(s):  
Carlos A. Duchanoy ◽  
Marco A. Moreno-Armendáriz ◽  
Carlos A. Cruz-Villar
Keyword(s):  
Dynamic Optimization ◽  
Optimization Algorithm ◽  
Physical Characteristics ◽  
Suspension System ◽  
Dynamic Interactions ◽  
Multi Objective ◽  
Damping Coefficients ◽  
Design Variables ◽  
Parameterized Model ◽  
Stiffness And Damping

In this paper a dynamic optimization methodology for designing a passive automotive damper is proposed. The methodology proposes to state the design problem as a dynamic optimization one by considering the nonlinear dynamic interactions between the damper and the other elements of the suspension system, emphasizing geometry, dimensional and movement constraints. In order to obtain realistic simulations of the suspension, a link between a Computer-Aided Engineering Model (CAEM) and a multi-objective dynamic optimization algorithm is developed. As design objectives we consider the vehicle safety and the passenger comfort which are represented by the contact area of the tire and the vibrations of the cockpit respectively. The damper is optimized by stating a set of physical variables that determine the stiffness and damping coefficients as independent variables for the dynamic optimization problem, they include the spring helix diameter, the spring wire diameter, the oil physical characteristics and the bleed orifice diameters among others. The optimization algorithm that we use to solve the problem at hand is a multi-objective evolutive optimization algorithm. For this purpose we developed a parameterized model of the damper which is used to link the CAE tools and the optimization software, thus enabling fitness evaluations during the dynamic optimization process. By selecting the physical characteristics of the damper as design variables instead of the typical stiffness and damping coefficients, it is possible to consider important design constrains as the damper size, movement limitations and anchor points. As result of the proposed methodology a set of blueprints of non dominated Pareto configurations of the damper are provided to the decision maker.

Sign in / Sign up

Export Citation Format

Share Document