scholarly journals Hybrid optimization design approach of asymmetric base-isolation coupling system for twin buildings

2021 ◽  
pp. 146134842199296
Author(s):  
Wonsuk Park ◽  
Seung-Yong Ok
Keyword(s):  
Vibration Control ◽  
Optimization Design ◽  
Base Isolation ◽  
Optimization Technique ◽  
Optimal Solution ◽  
Hybrid Optimization ◽  
Optimization Approach ◽  
Efficient Design ◽  
Coupling System ◽  
Twin Buildings

This study proposes a new configuration of asymmetric base-isolation coupling system for the vibration control of twin buildings, and also presents an efficient design method of using a hybrid optimization technique integrated with preference-based dimensionality reduction technique. The purpose of the proposed optimization approach is to guarantee the compromise optimal solution of well-balancing the mutually conflicting design objectives. In order to demonstrate the proposed approach, the adjacent 20-story twin buildings subjected to earthquake excitations were adopted as target buildings and it was verified through numerical examples that the proposed optimization technique can successfully find the optimal solution to achieve various design objectives in a balanced manner. The seismic performance was also compared with the existing different-story connection system with uniform distribution of dampers. The comparative results of the seismic performances between two systems clearly demonstrate that the proposed system can achieve great performance improvement over the existing system while maintaining balanced design preferences. Thus, it can be concluded that the proposed system can be a very effective system for the vibration control problem of the twin buildings.

Multi-Objective Optimization Design of Control Devices to Suppress Tall Buildings Vibrations against Earthquake Excitations Using Fuzzy Logic and Genetic Algorithms

2015 ◽  
pp. 787-817
Author(s):  
Saeid Pourzeynali ◽  
Shide Salimi
Keyword(s):  
Genetic Algorithms ◽  
Fuzzy Logic ◽  
Optimization Design ◽  
Base Isolation ◽  
Control Strategies ◽  
Optimal Solution ◽  
Base Shear ◽  
Viscous Dampers ◽  
Nsga Ii ◽  
Isolation Systems

The main objective of this chapter is to find the optimal values of the parameters of the base isolation systems and that of the semi-active viscous dampers using genetic algorithms (GAs) and fuzzy logic in order to simultaneously minimize the buildings' selected responses such as displacement of the top story, base shear, and so on. In this study, performance of base isolation systems, and semi-active viscous dampers are studied separately as different vibration control strategies. In order to simultaneously minimize the objective functions, a fast and elitist non-dominated sorting genetic algorithm (NSGA-II) approach is used to find a set of Pareto-optimal solution. To study the performance of semi-active viscous dampers, the torsional effects exist in the building due to irregularities, and unsymmetrical placement of the dampers is taken into account through 3D modeling of the building.

scholarly journals Hybrid Optimization Approach for the Design of Mechanisms Using a New Error Estimator

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
A. Sedano ◽  
R. Sancibrian ◽  
A. de Juan ◽  
F. Viadero ◽  
F. Egaña
Keyword(s):  
Evolutionary Algorithm ◽  
Optimization Technique ◽  
Hybrid Optimization ◽  
Error Estimator ◽  
Optimization Approach ◽  
Deterministic Approach ◽  
Dimensional Synthesis ◽  
Fitness Evaluation ◽  
Variable Space ◽  
Two Stages

A hybrid optimization approach for the design of linkages is presented. The method is applied to the dimensional synthesis of mechanism and combines the merits of both stochastic and deterministic optimization. The stochastic optimization approach is based on a real-valued evolutionary algorithm (EA) and is used for extensive exploration of the design variable space when searching for the best linkage. The deterministic approach uses a local optimization technique to improve the efficiency by reducing the high CPU time that EA techniques require in this kind of applications. To that end, the deterministic approach is implemented in the evolutionary algorithm in two stages. The first stage is the fitness evaluation where the deterministic approach is used to obtain an effective new error estimator. In the second stage the deterministic approach refines the solution provided by the evolutionary part of the algorithm. The new error estimator enables the evaluation of the different individuals in each generation, avoiding the removal of well-adapted linkages that other methods would not detect. The efficiency, robustness, and accuracy of the proposed method are tested for the design of a mechanism in two examples.

Tuned mass damper asymmetric coupling system for vibration control of adjacent twin buildings

2019 ◽  
Vol 23 (5) ◽  
pp. 954-968
Author(s):  
Seung-Yong Ok
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Tuned Mass Damper ◽  
Independent Control ◽  
Control Approach ◽  
Coupling System ◽  
Mass Damper ◽  
Asymmetric Coupling ◽  
Coupling Approach ◽  
Twin Buildings

It is widely known that, in the vibration control problem of two adjacent structures, an inter-building coupling approach with the connecting damper is more efficient than an independent control approach with the bracing damper. However, the inter-building coupling approach is only valid for two different structures. When the two structures are twin, the existing inter-building coupling approach does not work properly due to the response symmetry of the twin structures. To overcome such limitations, this study proposes a new control approach based on the asymmetric coupling system where the twin buildings are coupled with the connecting damper and the additional damper is installed asymmetrically to perturb the symmetry of the twin structures. Under this intentional asymmetric condition, the proposed system can fully maintain the control efficiency of the conventional inter-building coupling approach. The tuned mass damper–based asymmetric coupling system is considered as a numerical example, and the independent control system with tuned mass damper is further taken into account for comparison purpose. For the optimal design of the proposed system, a multi-objective optimization technique was introduced, and the efficiency of the proposed approach has been investigated through the numerical simulations of the 10-story twin structures. By comparing the control performances of the optimal solutions between the proposed asymmetric coupling systems and the independent control system, it was verified that the proposed asymmetric coupling system can be a new efficient system for the vibration control of adjacent twin structures.

A hybrid optimization strategy for the maintenance of the wheels of metro vehicles: Vehicle turning, wheel re-profiling, and multi-template use

2017 ◽  
Vol 232 (3) ◽  
pp. 832-841 ◽  
Author(s):  
Wei Zhu ◽  
Di Yang ◽  
Jun Huang
Keyword(s):  
Optimal Solution ◽  
Hybrid Optimization ◽  
Optimization Approach ◽  
Optimization Strategy ◽  
Wheel Wear ◽  
Rail Systems ◽  
Common Strategy ◽  
Shanghai Metro ◽  
Open Nature

The wheel–rail contact relationship has a great impact on the security and reliability of metro vehicles in service. In particular, wear modeling and maintenance optimization of the wheels play significant roles with regard to both safety and cost. However, it is difficult to provide a satisfactory model of wheel wear because of the open nature of real wheel–rail systems and the constantly varying environmental conditions in which they operate. Historically, re-profiling, which also has its limitation to some extent, was adopted as a common strategy to restore the original profiles of the worn wheels. Acknowledging that re-profiling is not the only strategy for dealing with wheel wear, the authors of this study have developed a more advanced optimization approach that includes two more strategies, namely, vehicle turning and multi-template use, to give as near an optimal solution as possible. Vehicle turning refers to the reversal of the vehicle’s orientation on the rail, whereas multi-template use refers to the situation where different re-profiling templates are used alternately. In this paper, re-profiling, vehicle turning, and multi-template use have been discussed separately. Then a hybrid optimization strategy for the maintenance of the wheels of metro vehicles has been proposed, with the aim of maximizing the wheel life while minimizing the relevant costs. An initial case study on the Shanghai Metro system shows that the proposed approach is able to provide a more reasonable solution for the optimization of the maintenance strategies.

Multi-Objective Optimization Design of Control Devices to Suppress Tall Buildings Vibrations against Earthquake Excitations Using Fuzzy Logic and Genetic Algorithms

2013 ◽  
pp. 180-215
Author(s):  
Saeid Pourzeynali ◽  
Shide Salimi
Keyword(s):  
Genetic Algorithms ◽  
Fuzzy Logic ◽  
Optimization Design ◽  
Base Isolation ◽  
Control Strategies ◽  
Optimal Solution ◽  
Base Shear ◽  
Viscous Dampers ◽  
Nsga Ii ◽  
Isolation Systems

The main objective of this chapter is to find the optimal values of the parameters of the base isolation systems and that of the semi-active viscous dampers using genetic algorithms (GAs) and fuzzy logic in order to simultaneously minimize the buildings’ selected responses such as displacement of the top story, base shear, and so on. In this study, performance of base isolation systems, and semi-active viscous dampers are studied separately as different vibration control strategies. In order to simultaneously minimize the objective functions, a fast and elitist non-dominated sorting genetic algorithm (NSGA-II) approach is used to find a set of Pareto-optimal solution. To study the performance of semi-active viscous dampers, the torsional effects exist in the building due to irregularities, and unsymmetrical placement of the dampers is taken into account through 3D modeling of the building.

scholarly journals A Hybrid Optimization Approach for the Enhancement of Efficiency of a Piezoelectric Energy Harvesting System

Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Mahidur R. Sarker ◽  
Ramizi Mohamed ◽  
Mohamad Hanif Md Saad ◽  
Muhammad Tahir ◽  
Aini Hussain ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Power Loss ◽  
Power Efficiency ◽  
Optimization Technique ◽  
Optimization Method ◽  
Hybrid Optimization ◽  
Piezoelectric Energy Harvesting ◽  
Optimization Approach ◽  
Piezoelectric Energy ◽  
Energy Harvesting System

This paper presents a hybrid optimization approach for the enhancement of performance of a piezoelectric energy harvesting system (PEHS). The existing PEHS shows substantial power loss during hardware implementation. To overcome the problem, this study proposes a hybrid optimization technique to improve the PEHS efficiency. In addition, the converter design as well as controller technique are enhanced and simulated in a MATLAB/Simulink platform. The controller technique of the proposed structure is connected to the converter prototype through the dSPACE DS1104 board (dSPACE, Paderborn, Germany). To enhance the proportional-integral voltage controller (PIVC) based on hybrid optimization method, a massive enhancement in reducing the output error is done in terms of power efficiency, power loss, rising time and settling time. The results show that the overall PEHS converter efficiency is about 85% based on the simulation and experimental implementations.

scholarly journals An Entropy Weight-Based Lower Confidence Bounding Optimization Approach for Engineering Product Design

2020 ◽  
Vol 10 (10) ◽  
pp. 3554 ◽  
Author(s):  
Jiachang Qian ◽  
Jiaxiang Yi ◽  
Jinlan Zhang ◽  
Yuansheng Cheng ◽  
Jun Liu
Keyword(s):  
Optimization Design ◽  
Optimal Solution ◽  
Kriging Model ◽  
Optimization Approach ◽  
Adaptive Optimization ◽  
Entropy Weight ◽  
Engineering Product ◽  
Lower Confidence ◽  
Different Dimensions ◽  
Adaptive Kriging

The optimization design of engineering products involving computationally expensive simulation is usually a time-consuming or even prohibitive process. As a promising way to relieve computational burden, adaptive Kriging-based design optimization (AKBDO) methods have been widely adopted due to their excellent ability for global optimization under limited computational resource. In this paper, an entropy weight-based lower confidence bounding approach (EW-LCB) is developed to objectively make a trade-off between the global exploration and the local exploitation in the adaptive optimization process. In EW-LCB, entropy theory is used to measure the degree of the variation of the predicted value and variance of the Kriging model, respectively. Then, an entropy weight function is proposed to allocate the weights of exploration and exploitation objectively and adaptively based on the values of information entropy. Besides, an index factor is defined to avoid the sequential process falling into the local regions, which is associated with the frequencies of the current optimal solution. To demonstrate the effectiveness of the proposed EW- LCB method, several numerical examples with different dimensions and complexities and the lightweight optimization design problem of an underwater vehicle base are utilized. Results show that the proposed approach is competitive compared with state-of-the-art AKBDO methods considering accuracy, efficiency, and robustness.

Structural Design of S-Bend Box for ITER Feeder Based on Optimization Technique of ANSYS

2010 ◽  
Author(s):  
Biao Dong ◽  
Kai-song Wang ◽  
Yun-tao Song
Keyword(s):  
Optimization Design ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Optimization Technique ◽  
Equivalent Stress ◽  
Optimal Solution ◽  
Parametric Modeling ◽  
State Variables ◽  
Practical Applications ◽  
Technical Parameters

On the premise that ensuring the reliability of structural strength, and in order to get the optimal structural parameters and the number of reinforcement rib of the ITER feeder S-bend box (SBB), so that its stress distribution is more uniform and reasonable under the critical pressure load, and the cost of materials is relatively smaller, this article, through theoretical calculations and inferences on the basis of the parametric modeling and static analysis and checking of SBB, setting up different reinforcement rib numbers, optimizes through the ANSYS optimization design module, with the maximum stress as the objection function, with and reasonable quality and displacement as state variables, with the size of wall thickness and the space of reinforcement rib as design variables. And it regulates true stress at stress concentration through submodeling of ANSYS and local solid modeling. The results of optimization analysis show that: SBB reached the optimal solution when the reinforcement rib number N of SBB takes 3, the maximum equivalent stress is 117 Mpa and the weight is 6417Kg. Finally, SBB structural parameters, which obtained through optimization design, are rounded according to GB. These meet the design requirements, correspond to the practical applications and provide technical parameters and basis for the future development of SBB.

scholarly journals Optimization Design of a Riser-Drill String Coupling System Based on CAE Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Shiyao Qin ◽  
Ruiming Wang ◽  
Deyi Fu ◽  
Gaowei Wang
Keyword(s):  
Optimization Design ◽  
Optimal Solution ◽  
Drill String ◽  
Dynamic Responses ◽  
Optimization Strategy ◽  
Effect Analysis ◽  
Coupling System ◽  
The Monte Carlo Method ◽  
Optimization Parameters ◽  
The Stability

In a riser-drill string coupling system, the drill string extends from platform to downhole, and its exterior tube is divided by mud line into two parts: riser for upside and borehole for downside. Due to such a pipe-in-pipe structure, an improved dynamic model is proposed to take the multipoint interactions between the inner and outer pipes into consideration. The dynamic responses of this system are analyzed by Computer Aided Engineering (CAE) techniques; specifically, it is numerically simulated in Abaqus; then, both the parametric sensitivity analysis and the main effect analysis are carried out in Isight to determine the optimization parameters and the optimization strategy. Moreover, six-sigma algorithm in Isight is applied to simultaneously drive the neighborhood cultivation genetic algorithm (NCGA) to conduct multiobjective optimization and drive the Monte Carlo method to analyze the stability of the obtained optimal solution. Based on the above investigations, a software package is developed via the secondary developments of both Abaqus and Isight. By this way, the optimization design of the riser-drill string coupling system based on dynamic analysis can be conducted effectively and efficiently.

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