Vibration control of Multi Degree of Freedom structure under earthquake excitation with TMD control and active control force using fuzzy logic method at the highest and the lowest story of the building
In this paper, Control system performance, as a passive and active control on the example building
under the Bam earthquake excitation, was studied. In order to passive and active control the structure TMD
system mounted on the top floor of the building and FLC method was used, respectively. Active control system
first applied to the lowest floor then to the highest point of the structure (applied to the TMD system).
Mathematical model of the building is established in MATLAB. Equation of motion was written for high rise
building and it was solved by state-space method, the Results are illustrated and compared.
Modeling of Granular Mixing using Markov Chains and the Discrete Element Methodjodoua
The document presents a method for modeling granular mixing using Markov chains and the discrete element method (DEM). It motivates the use of Markov chains to efficiently simulate granular mixing as an alternative to computationally expensive DEM simulations. The theory and definitions of Markov chains and operators are provided. The method is applied to simulate mixing in a cylindrical drum, and the effects of the number of states, time step, and learning time are investigated. Properties of the resulting operator like the invariant distribution and mixing rates are analyzed to characterize the mixing dynamics.
1) Dynamics is the study of how structures respond to dynamic or time-varying loads. Static loads do not change over time, while dynamic loads vary with time and can cause displacement, velocity, and acceleration responses in structures.
2) The key differences between static and dynamic loading are that dynamic loading produces inertia forces that cause accelerations, while static loading only produces displacements. These inertia forces contribute significantly to the internal elastic forces that a structure experiences under dynamic loading.
3) Common causes of dynamic effects in structures include initial conditions giving the structure an initial velocity, applied time-varying forces like wind or earthquakes, and support motions like ground shaking during an earthquake.
This document describes parametric design optimizations of trebuchet models conducted with Matlab and ANSYS software. A 2D trebuchet model in Matlab was optimized using a Lagrangian formulation to achieve a maximum range efficiency of 92.6%, higher than the previously reported maximum of 83%. A 3D trebuchet model in ANSYS including component dimensions and stresses was also optimized, achieving a maximum range efficiency of 83% with component safety factors above 2. Both models support the initial assertions regarding theoretical trebuchet efficiency.
Evaluation of Vibrational Behavior for A System With TwoDegree-of-Freedom Und...IJERA Editor
Analysis of the vibrational behavior of a system is extremely important, both for the evaluation of operating conditions, as performance and safety reason. The studies on vibration concentrate their efforts on understanding the natural phenomena and the development of mathematical theories to describe the vibration of physical systems. The purpose of this study is to evaluate an undamped system with two-degrees-of-freedom and demonstrate by comparing the results obtained in the experimental, numerical and analytical modeling the characteristics that describe a structure in terms of its natural characteristics. The experiment was conducted in PUC-MG where the data were acquired to determine the natural frequency of the system. We also developed an experimental test bed for vibrations studies for graduate and undergraduate students. In analytical modeling were represented all the important aspects of the system. In order, to obtain the mathematical equations is used MATLAB to solve the equations that describe the characteristics of system behavior. For the simulation and numerical solution of the system, we use a computational tool ABAQUS. The comparison between the results obtained in the experiment and the numerical was considered satisfactory using the exact solutions. This study demonstrates that calculation of the adopted conditions on a system with two-degrees-of-freedom can be applied to complex systems with many degrees of freedom and proved to be an excellent learning tool for determining the modal analysis of a system. One of the goals is to use the developed platform to be used as a didactical experiment system for vibration and modal analysis classes at PUC Minas. The idea is to give the students an opportunity to test, play, calculate and confirm the results in vibration and modal analysis in a low-cost platform
Application of Boundary Conditions to Obtain Better FEA ResultsKee H. Lee, P.Eng.
This document discusses applying proper boundary conditions in finite element analysis to obtain better results. It covers:
1) Typical boundary conditions like supports, connections, and structural symmetry to model structures accurately
2) Examples show boundary conditions significantly affect results like displacements and moments
3) Nonlinear behaviors from large deformations, materials, and contact require special boundary conditions in analysis
1) The document describes a two-component cold standby repairable system with one repairman and priority use for component 1.
2) It assumes component 2 is as good as new after repair, while component 1 follows a geometric process repair model and is not as good as new.
3) The goal is to determine an optimal replacement policy N* for the system based on the number of repairs for component 1 to minimize long-run expected costs.
The document provides an introduction to the finite element method (FEM). It discusses how FEM can be used to obtain approximate solutions to boundary value problems in engineering. It outlines the general steps involved, including preprocessing (defining the model), solution/processing (computing unknown values), and postprocessing (analyzing results). Examples of FEM applications include structural analysis, fluid flow, heat transfer, and more. The key aspects of FEM include discretizing the domain into simple elements, choosing shape functions to approximate variations within each element, and assembling the element equations into a global system of equations to solve.
Modeling of Granular Mixing using Markov Chains and the Discrete Element Methodjodoua
The document presents a method for modeling granular mixing using Markov chains and the discrete element method (DEM). It motivates the use of Markov chains to efficiently simulate granular mixing as an alternative to computationally expensive DEM simulations. The theory and definitions of Markov chains and operators are provided. The method is applied to simulate mixing in a cylindrical drum, and the effects of the number of states, time step, and learning time are investigated. Properties of the resulting operator like the invariant distribution and mixing rates are analyzed to characterize the mixing dynamics.
1) Dynamics is the study of how structures respond to dynamic or time-varying loads. Static loads do not change over time, while dynamic loads vary with time and can cause displacement, velocity, and acceleration responses in structures.
2) The key differences between static and dynamic loading are that dynamic loading produces inertia forces that cause accelerations, while static loading only produces displacements. These inertia forces contribute significantly to the internal elastic forces that a structure experiences under dynamic loading.
3) Common causes of dynamic effects in structures include initial conditions giving the structure an initial velocity, applied time-varying forces like wind or earthquakes, and support motions like ground shaking during an earthquake.
This document describes parametric design optimizations of trebuchet models conducted with Matlab and ANSYS software. A 2D trebuchet model in Matlab was optimized using a Lagrangian formulation to achieve a maximum range efficiency of 92.6%, higher than the previously reported maximum of 83%. A 3D trebuchet model in ANSYS including component dimensions and stresses was also optimized, achieving a maximum range efficiency of 83% with component safety factors above 2. Both models support the initial assertions regarding theoretical trebuchet efficiency.
Evaluation of Vibrational Behavior for A System With TwoDegree-of-Freedom Und...IJERA Editor
Analysis of the vibrational behavior of a system is extremely important, both for the evaluation of operating conditions, as performance and safety reason. The studies on vibration concentrate their efforts on understanding the natural phenomena and the development of mathematical theories to describe the vibration of physical systems. The purpose of this study is to evaluate an undamped system with two-degrees-of-freedom and demonstrate by comparing the results obtained in the experimental, numerical and analytical modeling the characteristics that describe a structure in terms of its natural characteristics. The experiment was conducted in PUC-MG where the data were acquired to determine the natural frequency of the system. We also developed an experimental test bed for vibrations studies for graduate and undergraduate students. In analytical modeling were represented all the important aspects of the system. In order, to obtain the mathematical equations is used MATLAB to solve the equations that describe the characteristics of system behavior. For the simulation and numerical solution of the system, we use a computational tool ABAQUS. The comparison between the results obtained in the experiment and the numerical was considered satisfactory using the exact solutions. This study demonstrates that calculation of the adopted conditions on a system with two-degrees-of-freedom can be applied to complex systems with many degrees of freedom and proved to be an excellent learning tool for determining the modal analysis of a system. One of the goals is to use the developed platform to be used as a didactical experiment system for vibration and modal analysis classes at PUC Minas. The idea is to give the students an opportunity to test, play, calculate and confirm the results in vibration and modal analysis in a low-cost platform
Application of Boundary Conditions to Obtain Better FEA ResultsKee H. Lee, P.Eng.
This document discusses applying proper boundary conditions in finite element analysis to obtain better results. It covers:
1) Typical boundary conditions like supports, connections, and structural symmetry to model structures accurately
2) Examples show boundary conditions significantly affect results like displacements and moments
3) Nonlinear behaviors from large deformations, materials, and contact require special boundary conditions in analysis
1) The document describes a two-component cold standby repairable system with one repairman and priority use for component 1.
2) It assumes component 2 is as good as new after repair, while component 1 follows a geometric process repair model and is not as good as new.
3) The goal is to determine an optimal replacement policy N* for the system based on the number of repairs for component 1 to minimize long-run expected costs.
The document provides an introduction to the finite element method (FEM). It discusses how FEM can be used to obtain approximate solutions to boundary value problems in engineering. It outlines the general steps involved, including preprocessing (defining the model), solution/processing (computing unknown values), and postprocessing (analyzing results). Examples of FEM applications include structural analysis, fluid flow, heat transfer, and more. The key aspects of FEM include discretizing the domain into simple elements, choosing shape functions to approximate variations within each element, and assembling the element equations into a global system of equations to solve.
The document discusses vibration control systems for structures and summarizes a presentation on the Yokohama Land Mark Tower in Japan. It describes how the tower implements a hybrid mass damper (HMD) system to control vibrations from earthquakes and wind. The HMD combines a tuned mass damper with an active control actuator. Two 170-ton HMD units were installed in the tower and automatically switch between active and passive modes to reduce vibrations by up to 50%. The hybrid system allows for increased efficiency and robustness compared to a purely passive or active vibration control system.
Desain dinding geser beton bertulang menggunakan software ETABSAfret Nobel
Dokumen tersebut membahas tentang desain shear wall pada struktur bangunan menggunakan software ETABS. Dokumen menjelaskan perbandingan perilaku struktur bangunan hanya menggunakan sistem rangka konvensional (SRPMK) dengan menambahkan shear wall. Dokumen juga menunjukkan langkah-langkah praktis dalam mendesain dan mengecek tulangan pada shear wall menggunakan ETABS.
shear walls are vertical elements of the horizontal force resisting system. Shear walls are constructed to counter the effects of lateral load acting on a structure.
This document discusses techniques for earthquake resistance, focusing on shear walls. Shear walls are very effective at resisting earthquake forces if properly designed. They have performed well in past earthquakes, reducing damage to both structural and non-structural elements. Shear wall buildings are commonly used in earthquake-prone areas because they are straightforward to construct and can lower construction costs while minimizing earthquake damage.
This document discusses structure control systems used to protect structures from vibrations during earthquakes or strong winds. It describes traditional seismic design approaches and modern structural control methods. Structural control systems can be passive, active, semi-active, or hybrid. Passive systems like base isolation and dampers dissipate energy without external power. Active systems precisely control structural response using external actuation, while semi-active systems adjust properties using small power inputs. The document provides examples of different control devices and their operating principles.
The document discusses the structure of the Earth and the causes of earthquakes. It describes the three main layers of the Earth - crust, mantle, and core. It explains that earthquakes are caused by the movement of tectonic plates at divergent, convergent, and transform plate boundaries. The document also summarizes methods of earthquake-resistant design, including base isolation devices that separate buildings from the ground and seismic dampers that absorb seismic energy. It notes that while base isolation can be used for existing structures, seismic dampers are more expensive to install. The conclusion emphasizes the importance of earthquake-resistant construction and quality control to ensure public safety.
The document discusses earthquakes and techniques for improving earthquake resistance in buildings. It defines earthquakes and describes how they occur due to movement in the earth's crust. It then covers types of earthquakes, causes and effects, seismic waves, and performance and design considerations for improving earthquake resistance. Specific techniques discussed include using shear walls, base isolation methods, energy dissipation devices, and keeping buildings in compression. The conclusion emphasizes following construction standards and periodic training to help assure earthquake-resistant buildings.
"Improved Decentralized Fractional PD Control of Structure Vibrations"
by Kang Xu 1, Liping Chen 2,, Minwu Wang 1, António M. Lopes 3, J. A. Tenreiro Machado 4 and Houzhen Zhai
Vibration Analysis of Structure using Tune Mass DamperIRJET Journal
This document discusses using a tuned mass damper (TMD) to control vibrations in structures. It begins by introducing TMDs and how they work, using a secondary mass attached to the primary structure through springs and dampers. The mass is tuned to have a natural frequency close to the structure.
It then describes analyzing a 17-story building model both with and without a TMD using response spectrum analysis software. Response spectrum analysis involves calculating the response of structures with different natural frequencies and damping when subjected to vibrations. Key responses like displacement, drift, and frequency are compared.
The study found that attaching a TMD, tuned to the building's fundamental frequency, at the top floor was effective at
State-Switched Control Algorithm for Multi Degree of Freedom Smart Base Isola...Sajjad Ahmad
International Conference on Earthquake Engineering and Seismology (ICEES 2011), NUST, Islamabad, Pakistan April 25-26, 2011
by
Muhammad Usman, Sajjad Ahmad, Hyung-Jo Jung
Investigation of behaviour of 3 degrees of freedom systems for transient loadseSAT Journals
Abstract
In this work, the energies dissipated by the spring mass damper system with three degrees of freedom are modelled and simulated for three types of external loads, namely, constant load, exponential decaying load overtime and a partial load over a time period. Two models of the spring mass damper system are modelled and the governing equations are derived. The velocities of the oscillators are estimated by solving the corresponding governing equations for loss of factor of 0.15. The kinetic and potential energies are calculated using the mass, velocity and stiffness of the oscillators and total energy is estimated. , when the load is changed from full load to a partial load over a time period, there is significant increase in the displacement and the velocity at near 0.75 sec, which means it dissipates more energy The contribution of the kinetic energy is minimal for oscillator 2 in all cases and the total energy is constituted mostly of potential energy and there is a substantial contribution both by kinetic and potential energy of oscillator 1 and 3 is presented in this paper. Index Terms: Vibration, 3 Degrees of freedom, Dampers, Loss factor, Transient loads.
IRJET- Effectiveness of Tuned Mass Dampers in Vibration Control of Multi-Sto...IRJET Journal
This document discusses the effectiveness of tuned mass dampers (TMDs) in vibration control of multi-story buildings. It analyzes a 40-story reinforced concrete building model with and without TMDs using response spectrum analysis. The response is measured in terms of displacement at the top floor. It finds that using multiple tuned mass dampers (MTMDs) with uniform mass distribution is most effective in reducing vibration compared to a single TMD (STMD) of the same total mass. The response reduction increases with higher TMD mass ratios and damping ratios. MTMDs can control vibrations in multiple modes more effectively than a single STMD tuned to the fundamental mode.
Hierarchical robust fuzzy sliding mode control for a class of simo under-actu...TELKOMNIKA JOURNAL
The development of the algorithms for single input multi output (SIMO) under-actuated systems with mismatched uncertainties is important. Hierarchical sliding-mode controller (HSMC) has been successfully employed to control SIMO under-actuated systems with mismatched uncertainties in a hierarchical manner with the use of sliding mode control. However, in such a control scheme, the chattering phenomenon is its main disadvantage. To overcome the above disadvantage, in this paper, a new compound control scheme is proposed for SIMO under-actuated based on HSMC and fuzzy logic control (FLC). By using the HSMC approach, a sliding control law is derived so as to guarantee the stability and robustness under various environments. The FLC as the second controller completely removes the chattering signal caused by the sign function in the sliding control law. The results are verified through theoretical proof and simulation software of MATLAB through two systems Pendubot and series double inverted pendulum.
Compound Control of Electromagnetic Linear Actuator Based on Fuzzy SwitchingTELKOMNIKA JOURNAL
Due to the motion control system of electromagnetic linear actuator (EMLA) is a nonlinear system
with poor controllability; single control strategy has been difficult to meet the requirements of its control. A
compound control strategy based on inverse system control (ISC) and proportional-integral (PI) is
designed in this paper. Switching between two algorithms, which is based on the fuzzy rules, prevents the
control algorithm to jitter and jump. System model is built under Matlab/Simulink to do simulation analysis.
The designed controller is integrated into the system simulation model and the system software of digital
signal processor (DSP) controller. Simulation and test results show that the compound control strategy
using fuzzy switching rules achieves the smooth transition of two control algorithms, and the goal of any
position location, and continuous adjustment in 0~4mm lift. Positioning accuracy is up to ± 0.02mm, while
the response time is less than 10ms.
Stability by assigning structures by applying the multivariable subspace iden...TELKOMNIKA JOURNAL
In this paper, a controller for a doubly fed induction generator (DFIG) connected to a wind system is proposed. This control assigning its own structures as an optimal control method, the electric model in the DFIG state space is also shown, for which it is expected to estimate a linear model through the subspace technique and thus to design the controller. It will be possible to show that a structure assignment controller is undoubtedly a good option for the control of multivariable systems. The results of the output signals will be analyzed when applying the controller, assigning their own structures, which will allow us to observe that the response and disturbance times are below two tenths of a second.
This document presents an investigation of the behavior of 3 degree of freedom spring mass damper systems subjected to transient loads. Two models of the spring mass damper system are modeled and their governing equations are derived. The velocities of the oscillators are estimated by solving the governing equations for a loss factor of 0.15. The kinetic and potential energies are calculated using the mass, velocity and stiffness of the oscillators to estimate the total energy. It is found that when the load changes from full to partial over time, there is a significant increase in displacement and velocity, dissipating more energy.
This document discusses investigating the behavior of a 3 degree of freedom spring mass damper system subjected to transient loads. It presents two models of the system with different damper configurations and derives the governing equations. The velocities and energies (kinetic and potential) of the oscillators are estimated by solving the equations for an exponential decaying, constant, and partial load over time. The results show the contribution of kinetic energy is minimal for oscillator 2 in all cases, while potential energy and contributions from oscillators 1 and 3 depend on the load type.
Seismic response of a cable-stayed bridge: active and passive control system...Franco Bontempi
This paper describes the Benchmark Problem for controlled cable-stayed bridges. The benchmark in
question is the first to be related directly to bridges. It follows on from past experience and
experimentation, devoted to buildings, developed at an international level. These past experiences focused
upon buildings subjected to wind and earthquake excitation. In this paper seismic excitation is explored in
relation to bridges.
Three different schemes of active control are compared with each other. Their performance is also
compared with the two most widely used passive control systems which summarize present energy
dissipation practice.
Optimal Design of Hysteretic Dampers Connecting 2-MDOF Adjacent Structures fo...CSCJournals
This document discusses optimal design of hysteretic dampers connecting two adjacent multi-degree of freedom (MDOF) structures subjected to random excitations. Three models are analyzed: 1) two 3-story buildings, 2) two 10-story buildings, and 3) a 10-story building adjacent to a 20-story building. The connecting damper properties are optimized to minimize the total energy stored in the structures. Results show that at the optimal damper properties, the response of each structure is reduced and the total system energy is minimized.
COUPLED STRUCTURAL DYNAMIC RESPONSE USING PASSIVE DAMPERSSuzana Avila
1) The document discusses using passive dampers to couple the structural dynamic response of two adjacent buildings to reduce damage during earthquakes.
2) It presents numerical models of different combinations of coupled structures varying in height and analyzes their response when subjected to earthquake accelerations.
3) The analysis shows that coupling is most effective when the height difference between the two structures is less than a ratio of two, and additional dampers may be needed if the height ratio is greater. The effectiveness depends on the properties of both the connecting damper and differences in the structures' mass, stiffness, and heights.
DESIGN OF OBSERVER BASED QUASI DECENTRALIZED FUZZY LOAD FREQUENCY CONTROLLER ...ijfls
This paper proposes Fuzzy Quasi Decentralized Functional Observers (FQDFO) for Load Frequency Control of inter-connected power systems. From the literature, it is well noticed about the need of
Functional Observers (FO’s) for power system applications. In past, conventional Functional Observers are used. Later, these conventional Functional Observers are replaced with Quasi Decentralized
Functional Observers (QDFO) to improve the system performance. In order to increase the efficacy of the
system, intelligent controllers gained importance. Due to their expertise knowledge, which is adaptive in
nature is applied successfully for FQDFO. For supporting the validity of the proposed observer FQDFO,
it is compared with full order Luenberger observer and QDFO for a two-area inter connected power system by taking parametric uncertainties into consideration. Computational results proved the robustness of the proposed observer.
DESIGN OF OBSERVER BASED QUASI DECENTRALIZED FUZZY LOAD FREQUENCY CONTROLLER ...Wireilla
ABSTRACT
This paper proposes Fuzzy Quasi Decentralized Functional Observers (FQDFO) for Load Frequency Control of inter-connected power systems. From the literature, it is well noticed about the need of Functional Observers (FO’s) for power system applications. In past, conventional Functional Observers are used. Later, these conventional Functional Observers are replaced with Quasi Decentralized Functional Observers (QDFO) to improve the system performance. In order to increase the efficacy of the system, intelligent controllers gained importance. Due to their expertise knowledge, which is adaptive in nature is applied successfully for FQDFO. For supporting the validity of the proposed observer FQDFO, it is compared with full order Luenberger observer and QDFO for a two-area inter connected power system by taking parametric uncertainties into consideration. Computational results proved the robustness of the proposed observer.
The document discusses vibration control systems for structures and summarizes a presentation on the Yokohama Land Mark Tower in Japan. It describes how the tower implements a hybrid mass damper (HMD) system to control vibrations from earthquakes and wind. The HMD combines a tuned mass damper with an active control actuator. Two 170-ton HMD units were installed in the tower and automatically switch between active and passive modes to reduce vibrations by up to 50%. The hybrid system allows for increased efficiency and robustness compared to a purely passive or active vibration control system.
Desain dinding geser beton bertulang menggunakan software ETABSAfret Nobel
Dokumen tersebut membahas tentang desain shear wall pada struktur bangunan menggunakan software ETABS. Dokumen menjelaskan perbandingan perilaku struktur bangunan hanya menggunakan sistem rangka konvensional (SRPMK) dengan menambahkan shear wall. Dokumen juga menunjukkan langkah-langkah praktis dalam mendesain dan mengecek tulangan pada shear wall menggunakan ETABS.
shear walls are vertical elements of the horizontal force resisting system. Shear walls are constructed to counter the effects of lateral load acting on a structure.
This document discusses techniques for earthquake resistance, focusing on shear walls. Shear walls are very effective at resisting earthquake forces if properly designed. They have performed well in past earthquakes, reducing damage to both structural and non-structural elements. Shear wall buildings are commonly used in earthquake-prone areas because they are straightforward to construct and can lower construction costs while minimizing earthquake damage.
This document discusses structure control systems used to protect structures from vibrations during earthquakes or strong winds. It describes traditional seismic design approaches and modern structural control methods. Structural control systems can be passive, active, semi-active, or hybrid. Passive systems like base isolation and dampers dissipate energy without external power. Active systems precisely control structural response using external actuation, while semi-active systems adjust properties using small power inputs. The document provides examples of different control devices and their operating principles.
The document discusses the structure of the Earth and the causes of earthquakes. It describes the three main layers of the Earth - crust, mantle, and core. It explains that earthquakes are caused by the movement of tectonic plates at divergent, convergent, and transform plate boundaries. The document also summarizes methods of earthquake-resistant design, including base isolation devices that separate buildings from the ground and seismic dampers that absorb seismic energy. It notes that while base isolation can be used for existing structures, seismic dampers are more expensive to install. The conclusion emphasizes the importance of earthquake-resistant construction and quality control to ensure public safety.
The document discusses earthquakes and techniques for improving earthquake resistance in buildings. It defines earthquakes and describes how they occur due to movement in the earth's crust. It then covers types of earthquakes, causes and effects, seismic waves, and performance and design considerations for improving earthquake resistance. Specific techniques discussed include using shear walls, base isolation methods, energy dissipation devices, and keeping buildings in compression. The conclusion emphasizes following construction standards and periodic training to help assure earthquake-resistant buildings.
Similar to Vibration control of Multi Degree of Freedom structure under earthquake excitation with TMD control and active control force using fuzzy logic method at the highest and the lowest story of the building
"Improved Decentralized Fractional PD Control of Structure Vibrations"
by Kang Xu 1, Liping Chen 2,, Minwu Wang 1, António M. Lopes 3, J. A. Tenreiro Machado 4 and Houzhen Zhai
Vibration Analysis of Structure using Tune Mass DamperIRJET Journal
This document discusses using a tuned mass damper (TMD) to control vibrations in structures. It begins by introducing TMDs and how they work, using a secondary mass attached to the primary structure through springs and dampers. The mass is tuned to have a natural frequency close to the structure.
It then describes analyzing a 17-story building model both with and without a TMD using response spectrum analysis software. Response spectrum analysis involves calculating the response of structures with different natural frequencies and damping when subjected to vibrations. Key responses like displacement, drift, and frequency are compared.
The study found that attaching a TMD, tuned to the building's fundamental frequency, at the top floor was effective at
State-Switched Control Algorithm for Multi Degree of Freedom Smart Base Isola...Sajjad Ahmad
International Conference on Earthquake Engineering and Seismology (ICEES 2011), NUST, Islamabad, Pakistan April 25-26, 2011
by
Muhammad Usman, Sajjad Ahmad, Hyung-Jo Jung
Investigation of behaviour of 3 degrees of freedom systems for transient loadseSAT Journals
Abstract
In this work, the energies dissipated by the spring mass damper system with three degrees of freedom are modelled and simulated for three types of external loads, namely, constant load, exponential decaying load overtime and a partial load over a time period. Two models of the spring mass damper system are modelled and the governing equations are derived. The velocities of the oscillators are estimated by solving the corresponding governing equations for loss of factor of 0.15. The kinetic and potential energies are calculated using the mass, velocity and stiffness of the oscillators and total energy is estimated. , when the load is changed from full load to a partial load over a time period, there is significant increase in the displacement and the velocity at near 0.75 sec, which means it dissipates more energy The contribution of the kinetic energy is minimal for oscillator 2 in all cases and the total energy is constituted mostly of potential energy and there is a substantial contribution both by kinetic and potential energy of oscillator 1 and 3 is presented in this paper. Index Terms: Vibration, 3 Degrees of freedom, Dampers, Loss factor, Transient loads.
IRJET- Effectiveness of Tuned Mass Dampers in Vibration Control of Multi-Sto...IRJET Journal
This document discusses the effectiveness of tuned mass dampers (TMDs) in vibration control of multi-story buildings. It analyzes a 40-story reinforced concrete building model with and without TMDs using response spectrum analysis. The response is measured in terms of displacement at the top floor. It finds that using multiple tuned mass dampers (MTMDs) with uniform mass distribution is most effective in reducing vibration compared to a single TMD (STMD) of the same total mass. The response reduction increases with higher TMD mass ratios and damping ratios. MTMDs can control vibrations in multiple modes more effectively than a single STMD tuned to the fundamental mode.
Hierarchical robust fuzzy sliding mode control for a class of simo under-actu...TELKOMNIKA JOURNAL
The development of the algorithms for single input multi output (SIMO) under-actuated systems with mismatched uncertainties is important. Hierarchical sliding-mode controller (HSMC) has been successfully employed to control SIMO under-actuated systems with mismatched uncertainties in a hierarchical manner with the use of sliding mode control. However, in such a control scheme, the chattering phenomenon is its main disadvantage. To overcome the above disadvantage, in this paper, a new compound control scheme is proposed for SIMO under-actuated based on HSMC and fuzzy logic control (FLC). By using the HSMC approach, a sliding control law is derived so as to guarantee the stability and robustness under various environments. The FLC as the second controller completely removes the chattering signal caused by the sign function in the sliding control law. The results are verified through theoretical proof and simulation software of MATLAB through two systems Pendubot and series double inverted pendulum.
Compound Control of Electromagnetic Linear Actuator Based on Fuzzy SwitchingTELKOMNIKA JOURNAL
Due to the motion control system of electromagnetic linear actuator (EMLA) is a nonlinear system
with poor controllability; single control strategy has been difficult to meet the requirements of its control. A
compound control strategy based on inverse system control (ISC) and proportional-integral (PI) is
designed in this paper. Switching between two algorithms, which is based on the fuzzy rules, prevents the
control algorithm to jitter and jump. System model is built under Matlab/Simulink to do simulation analysis.
The designed controller is integrated into the system simulation model and the system software of digital
signal processor (DSP) controller. Simulation and test results show that the compound control strategy
using fuzzy switching rules achieves the smooth transition of two control algorithms, and the goal of any
position location, and continuous adjustment in 0~4mm lift. Positioning accuracy is up to ± 0.02mm, while
the response time is less than 10ms.
Stability by assigning structures by applying the multivariable subspace iden...TELKOMNIKA JOURNAL
In this paper, a controller for a doubly fed induction generator (DFIG) connected to a wind system is proposed. This control assigning its own structures as an optimal control method, the electric model in the DFIG state space is also shown, for which it is expected to estimate a linear model through the subspace technique and thus to design the controller. It will be possible to show that a structure assignment controller is undoubtedly a good option for the control of multivariable systems. The results of the output signals will be analyzed when applying the controller, assigning their own structures, which will allow us to observe that the response and disturbance times are below two tenths of a second.
This document presents an investigation of the behavior of 3 degree of freedom spring mass damper systems subjected to transient loads. Two models of the spring mass damper system are modeled and their governing equations are derived. The velocities of the oscillators are estimated by solving the governing equations for a loss factor of 0.15. The kinetic and potential energies are calculated using the mass, velocity and stiffness of the oscillators to estimate the total energy. It is found that when the load changes from full to partial over time, there is a significant increase in displacement and velocity, dissipating more energy.
This document discusses investigating the behavior of a 3 degree of freedom spring mass damper system subjected to transient loads. It presents two models of the system with different damper configurations and derives the governing equations. The velocities and energies (kinetic and potential) of the oscillators are estimated by solving the equations for an exponential decaying, constant, and partial load over time. The results show the contribution of kinetic energy is minimal for oscillator 2 in all cases, while potential energy and contributions from oscillators 1 and 3 depend on the load type.
Seismic response of a cable-stayed bridge: active and passive control system...Franco Bontempi
This paper describes the Benchmark Problem for controlled cable-stayed bridges. The benchmark in
question is the first to be related directly to bridges. It follows on from past experience and
experimentation, devoted to buildings, developed at an international level. These past experiences focused
upon buildings subjected to wind and earthquake excitation. In this paper seismic excitation is explored in
relation to bridges.
Three different schemes of active control are compared with each other. Their performance is also
compared with the two most widely used passive control systems which summarize present energy
dissipation practice.
Optimal Design of Hysteretic Dampers Connecting 2-MDOF Adjacent Structures fo...CSCJournals
This document discusses optimal design of hysteretic dampers connecting two adjacent multi-degree of freedom (MDOF) structures subjected to random excitations. Three models are analyzed: 1) two 3-story buildings, 2) two 10-story buildings, and 3) a 10-story building adjacent to a 20-story building. The connecting damper properties are optimized to minimize the total energy stored in the structures. Results show that at the optimal damper properties, the response of each structure is reduced and the total system energy is minimized.
COUPLED STRUCTURAL DYNAMIC RESPONSE USING PASSIVE DAMPERSSuzana Avila
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Vibration control of Multi Degree of Freedom structure under earthquake excitation with TMD control and active control force using fuzzy logic method at the highest and the lowest story of the building
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 8, Issue 5 (Sep. - Oct. 2013), PP 07-12
www.iosrjournals.org
www.iosrjournals.org 7 | Page
Vibration control of Multi Degree of Freedom structure under
earthquake excitation with TMD control and active control force
using fuzzy logic method at the highest and the lowest story of the
building
M. Ali Lotfollahi Yaghin1
, M. Reza Bagerzadeh Karimi2
, B. Bagheri3
,
V. Sadeghi Balkanlou4
1
Prof. of Faculty of Civil Engineering, University of Tabriz, IRAN
2
Department of Civil Engineering, Islamic Azad University, Maraghe Branch, IRAN
3
Department of Civil Engineering, Shomal University, IRAN
4
Young Researchers and Elite Club, Islamic Azad University, Tabriz branch, IRAN
Abstract: In this paper, Control system performance, as a passive and active control on the example building
under the Bam earthquake excitation, was studied. In order to passive and active control the structure TMD
system mounted on the top floor of the building and FLC method was used, respectively. Active control system
first applied to the lowest floor then to the highest point of the structure (applied to the TMD system).
Mathematical model of the building is established in MATLAB. Equation of motion was written for high rise
building and it was solved by state-space method, the Results are illustrated and compared.
Keywords : MATLAB; Active and Passive control; Fuzzy Logic Controller; Tuned Mass Damper
I. INTRODUCTION
The developments in engineering science in vibration control of structures, and security needs for
occupants to feel safe against earthquake cause researchers to study more in the field of vibration control of
structures. Vibration control systems can be divided into Passive and Active control systems. Passive control
systems add damping to the structure, naturally, when an earthquake occurres. However, their control capacity is
limited. But these systems have been widely used because of their simplicity and low cost. The active control
systems use external energy when an earthquake happens. This energy produced by algorithm and applied to the
structure has the advantage of having stronger capacity than Passive control systems. Also it can be designed to
influence a number of vibration modes, and it is the most suited for an MDOF structure. On the other hand,
passive control systems and active control systems are used together in order to decrease the energy
requirements. Researches show that increasing the height of buildings could increase the flexibility; thus, the
importance of the active control systems has increased [1]. Rahmi and et al. [1] studied about vibration control
of structures using fuzzy logic and PD controller and an actuator was applied at the highest point of the structure
where the TMD had been located. Seung-Yong and et al. [2] investigated about vibration control of structure
using a technique with fuzzy logic method. Mahmud and et al. [3] examined an optimized control for an
earthquake excitation on a structure. Hasan and et al. [4] studied about FSMC which is one of the active control
algorithms. Pourzeynal and et al. [5] studied about vibration control of structure against earthquake excitation
using GFLC and LQR algorithms and compared with TMD controller. Bijan and et al. [6] used experimental
analysis and investigated a five-story building where ATMD system was controlled by FLC and LQR method.
As it is clear by researches only the effects of control systems are studied and investigated on civil engineering
structures, but the effects of the opportunities and the location of control systems, namely applying at the highest
and the lowest point of the structure in order to reach optimized responses, are not investigated. The present
paper studied and investigated a 10-story building using active control system which was first applied to the
TMD system then to the lowest floor of the building. Also the results were compared with the responses of the
TMD control system in order to show robustness of FLC in example building.
II. STRUCTURAL MODEL
The equation of motion for a multi-degree-of-freedom structure subjected to seismic excitation xg(t) without
any control system can be written as:
M x + C x + K x = − M r xg(t) (1)
2. Vibration control of Multi Degree of Freedom structure under earthquake excitation
www.iosrjournals.org 8 | Page
In which the n × 1 vector x the relative displacement of each story; n is the number of stories; the n × 1
vector{r} is the influence vector representing the displacement of each degree of freedom resulting from static
application of a unit ground displacement; and n × n matrices [M], [C] and [k] represent the structure mass,
damping, and stiffness matrices, respectively. The structural damping matrix [C] is assumed to be a proportion
of the mass and stiffness matrices, as given in the following [5]:
C = a0 M + b0[K] (2)
Where a0 = ξi ×
2ωι ×ωj
ωι +ωj
and b0 = ξi ×
2
ωι +ωj
, a0 and b0 are the proportional coefficient; ωιandωjare the
structural modal frequencies and ξi and ξj are the structural damping ratio for modes i and j, respectively. This
paper also studied the effects of TMD, a classical engineering device consisting of a mass, a spring and a
damper, on multi-degree- of-freedom structure. For this purpose, as shown in Fig. 1, a TMD system is mounted
on the top floor of the building. The equation of motion of multi-degree-of-freedom linear system which is
subjected to a seismic excitation xg t and active control action f can be written as:
MT xT + CT xT + KT xT = − MT rT xg t + D {f} (3)
In which the 1n vector xT designates the relative displacements of each story. Square matrices MT , CT ,
KT and rT are the same explained in Eq. 1, and n × 1 vector {f} contains the externally applied control forces
whose locations are identified through the matrix D .
(a) (b)
Fig. 1 Example building of using active control system: a) applied to the first floor b) applied to the
TMD system
III. FUZZY LOGIC
Fuzzy set was introduced by Lotfi Zadeh in 1965. Fuzzy set deals with uncertain phenomena often
presented in real-life application. What makes fuzzy logic and classical mathematics different is that the fuzzy
set theory allows object to have any degrees of membership between zero and 1 but the classical mathematics
requires objects to have zero or 1 [12].
The basic structure of fuzzy system which works with Fuzzy Logic is defined as follows:
Fuzzifier: inputs measured in the control process and converted into fuzzy linguistic value using the rules as
given in table 1. In order to limit the amplitude of variables between 1 and -1, they are divided into their
maximums.
Fuzzy rules: this is the collection of the expert control rules (table 1). These rules are used to connect outputs
and inputs in fuzzy logic system.
Fuzzy interference engine: after converting the inputs to linguistic variables, the outputs are defined by fuzzy
logic rules.
Defuzzifier: then the defuzzifier converts the outputs of fuzzy logic system to crisp data [13]. The basic structure
of fuzzy logic algorithm is illustrated in Fig. 2.
3. Vibration control of Multi Degree of Freedom structure under earthquake excitation
www.iosrjournals.org 9 | Page
.
Fig. 2 fuzzy logic components
IV. NUMERICAL STUDY
In order to investigate the effects of active control system and TMD to decrease the responses under the
earthquake excitation of BAM earthquake, happened in 2003 in IRAN (Fig. 3), a 10-story building was modeled
in MATLAB (Fig. 1). The structure’s properties of example building are provided in Table 2.
Fig. 3 Bam earthquake excitation input to the structure
To passive control the vibration TMD system is mounted on the top floor of the building and for active
controlling the structure it was applied to the first floor then to the highest point of the structure where the TMD
system mounted. In order to reach maximum decrease of vibration of using TMD system, the mass of the TMD
obtained by trial and error about 1% of the whole building’s mass. To find the stiffness of the passive control
system the natural frequency of TMD is tuned to the main natural frequency of the main structure, as follows:
𝜔𝑖
2
× 𝑚 𝑇𝑀𝐷 = 𝑘 𝑇𝑀𝐷 (4)
In which mTMD and kTMD and ωι are the mass, stiffness, and the main frequency of the first mode, respectively.
The most optimized parameter of this system is defined by maximum decrease of responses of the building.
Also the same parameters of the mass were used for active control system when active control force applied to
the TMD system. In this study, Matlab simulink with fuzzy toolbox is used. The aim of the fuzzy logic control
system for the structural system uses e and de as inputs and u as an output where the active control system is
applied. For each of inputs, five rectangular membership functions are used which cover the amplitude of each
input. Also, nine rectangular membership functions are used for outputs (Fig. 4). Fuzzy logic controller with
Mamdani and Centroid methods were used in fuzzification and defuzzification, respectively. Scaling factors (se,
Table 1. fuzzy rules
e (displacement) de(velocity)
VNB VNS VZE VPS VPB
XNB UPL UPB UPM UPS UZE
XNS UPB UPM UPS UZE UNS
XZE UPM UPS UZE UNS UNM
XPS UPS UZE UNS UNM UNB
XPB UZE UNS UNM UNB UNL
Table 2
Example building structure data
Stories Mass (kg) Stiffness (kg/m)
1 42180 114938011
2 42180 114938011
3 41791 87486851
4 41791 87486851
5 41430 65258739
6 41430 65258739
7 41097 47547051
8 41097 47547051
9 40791 33696384
10 40791 33696384
TMD 4146 177333
4. Vibration control of Multi Degree of Freedom structure under earthquake excitation
www.iosrjournals.org 10 | Page
sde, su) are used to set in Fig. 5. The fuzzy input and output variables’ membership function abbreviations used
to define the fuzzy space are: (X/V)NB = negative big; (X/V)NS = negative small; (X/V)ZE = zero; (X/V)PB =
positive big; (X/V)PS = positive small (for input variable); and (U)NL = negative large; (U)NB = negative big;
(U)NM = negative medium; (U)NS = negative small; (U)ZE = zero; (U)PL = positive large; (U)PB = positive
big; (U)PM = positive medium; (U)PS = positive small (for output variable).
Fig. 4 Membership function
Fig. 5 Closed-loop model of the structure with fuzzy logic controller
As it is clear from table 3, responses of the structure for the top floor of the building (10th floor) show the
proportion of controlled structure, the results are 86.1%, 27.8%, 8.4% for displacement, 75.7%, 29.6%, 14.8%
for velocity and 88.7%, 33.3%, 25.6% for acceleration controlled by TMD and FLC systems where the active
control system applied to the first floor and to the TMD system, respectively. Figures 6 - 8 show the responses
(displacement and acceleration) for the uncontrolled and the controlled structure. As it can be seen from figures
6–8 the amplitude of vibration has decreased. Also, to clarify the results, displacements of floors are illustrated
in fig.9.
Fig. 6 passive control of displacement and acceleration for the 10th floor using TMD
Table 3
Comparison between the effects of control system on structure under Bam Earthquake
stories
Max. responses
of uncontrolled structure
Max. responses
of controlled structure
Ratios
Passive
control system
with TMD
Active control
system applied to
the first floor
Active control
system applied
to TMD
[2]/[1] [3]/[1] [4]/[1]
[1] [2] [3] [4] [5] [6] [7]
Displacement (m)
10th
0.036 0.031 0.01 0.003 0.861 0.278 0.084
Velocity (m/s)
10th
0.247 0.187 0.073 0.0366 0.757 0.296 0.148
Acceleration (m/s^2)
10th
2.505 2.221 0.833 0.643 0.887 0.333 0.256
5. Vibration control of Multi Degree of Freedom structure under earthquake excitation
www.iosrjournals.org 11 | Page
Fig. 7 Active control of displacement and acceleration for the 10th floor with FLC method when control
force applied at the lowest floor of the building
Fig. 8 Active control of displacement and acceleration for the 10th floor with FLC method when control force
applied to the TMD system
Fig. 9 Displacements
On the other hand, the fuzzy logic application is investigated against different disturbance using ground motion
of TABAS earthquake, happened in 1999 in IRAN, the acceleration was about 0.84g, also the mass of each floor
increased about 25%. Robustness of FLC has been investigated through this variety of buildings’ parameters.
The results in Table 4 show the robustness of FLC even for different parameters of inputs in example building.
Table 4
Comparison between the effects of control system on structure under Tabas earthquake for displacement
stories
Maximum responses
of uncontrolled structure
Maximum responses of controlled structure
TMD FLC (down) FLC (up)
Displacement (m)
10 0.313 0.301 0.085 0.034
6. Vibration control of Multi Degree of Freedom structure under earthquake excitation
www.iosrjournals.org 12 | Page
V. CONCLUSION
In the present study when the active control force applied on certain parts of the building from the
numerical results of the study, it is found that:
1) In view of the time history of the responses, the results show that when the active control force is applied to
two certain parts of the example building are more satisfactory compared when the passive control system
(TMD) is only used.
2) In this study as it is clear by table 3, the most satisfactory control case was found when active control
system applied to the TMD system.
3) Performance of designed FLC is checked for different disturbance using ground motion of TABAS, and
also changed some properties of structure. Simulation’s results show that proposed controller (FLC) has a
satisfactory performance and does not get worse. Decrease in vibration amplitudes supports this result
(Table 4).
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