This paper presented temperature scanning tests of the viscoelastic materials firstly. Use of viscoelastic dampers in reducing wind and earthquakeinduced motion of building structures. Article information, pdf download for model, tests and application. The seismic response control of multistory frame structures using optimally placed viscoelastic dampers veds within consideration of soilstructure interaction ssi effect is investigated in this paper. The viscoelastic structural damper application can perform the timedomain and frequencydomain analyses for a typical viscoelastic damper. On the basis of extensive analytical and experimental investigations, some practical issues associated with the application of viscoelastic dampers to building structures for seismic performance en. Viscoelastic damper connected to adjacent structures involving seismic isolation. Seismic response of steel frame structures with added. Mechanical pneumatic and material dampers sorbothane. Dynamic responses of coretubes with semiflexible suspension. Pdf modeling of a viscoelastic damper and its application. Numerical results demonstrating the response reducing effect of viscoelastic dampers are also presented.
Jun 01, 2017 viscous fluid dampers vfds and viscoelastic ve solid dampers belong to rate dependent passive dampers. Pdf download for study on mechanical properties of high damping. Before these devices can be incorporated into a structures design, there is, of. Viscoelastic structural dampers have been implemented into structural layouts as a means to limit the strain and decrease the risk of failure in building components due to. Material dampers apply to an array of industrial applications. Energy dissipation dampers viscoelasticity friction. These tuned mass dampers are in general less costly than the more. Optimal seismic retrofit of fractional viscoelastic dampers. A new configuration of coretubes with semiflexible suspension systems csfss is presented in this paper. The viscoelastic dampers and damping parameters are tested and monitored by our inhouse test lab and independent test laboratories based on safety standard kta 3205. Optimal design of viscoelastic dampers in frame structures. Damping elements involving layers of viscoelastic materials are often used for reduction of seismic and wind induced vibrations in buildings and other tall structures. During the march 2002 servicing mission by space shuttle sts 109, the hubble space telescope hst was refurbished with two new solar arrays that now provide all of its power.
Use of viscoelastic dampers in reducing wind and earthquakeinduced motion. Model, tests and application design for viscoelastic dampers. Viscoelastic dampers as energy dissipation devices for. A procedure for evaluating the ve damping effect when added to a structure is proposed in which the damping effect of ve dampers is incorporated into modal damping. The feasibility of using viscoelastic ve dampers to mitigate earthquake. The system is assumed to be elastic and responses of the system are obtained in frequency domain for stationary random seismic excitations. The configuration, simplified model and the formulation of the multidegrees of freedom equations of motion for this structure are given. Design and implementation of tuned viscoelastic dampers for vibration control in milling. The model allows viscoelastic material functions to be readily determined either directly from the experimental data or through interconversion from a function established in another domain. Published experimental data from a viscoelastic liquid. The properties of ve dampers are briefly described. Life cycle testing of viscoelastic material for hubble.
Traditional approach to controlling vibration in a milling system is to develop control mechanisms for cutting. Considering the possibility of earthquake occurrence during a structure lifetime, minimizing the life. Experimental and analytical study on design performance of. Optimal seismic retrofit of fractional viscoelastic. The evaluation of steel frame structures with viscoelastic.
Pdf viscoelastic damper connected to adjacent structures. Viscoelastic coupling dampers vcds for enhanced wind and. Analytical modeling of viscoelastic dampers for structural. A viscoelastic damper particularly suited for use in a rotor system of a helicopter or the like is provided to damp leadlag motion of the blade relative to the rotor hub. Detailed computational procedures for fitting and interconversion are discussed and illustrated. In recent years, viscoelastic dampers veds have been widely used in many mid and highrise buildings. Viscous fluid dampers vfds and viscoelastic ve solid dampers belong to rate dependent passive dampers. At the same time, 52 viscoelastic dampers are applied for seismic retrofit design on xian petrol hotel, and the finite analysis for structures with and without dampers are carried out under frequentearthquake and infrequentearthquake excitations. Therefore, the amount of normal strain of each specimen is. The elastomeric pads in damper a contained a single rubber layer with no internal reinforcement fig. Viscoelastic damper is a kind of commonly used passive control device for.
Jun 01, 2017 modeling of a viscoelastic damper and its application in structural control. The dynamic responses of structures with and without dampers are compared. An elongate body of viscoelastic material has an inner plate embedded centrally therein and extending longitudinally thereof. Regarding the experiment, we report the results of an evaluation of seismic resistance against input in an. These dampers suppress bending and torsionmode blade vibrations, which are excited by unsteady aerodynamic forces during operation. Vibration damping and isolating in engineered designs. Dampers a, b, and d contained two elastomeric pads of 200 by 200 mm plan dimensions.
Two viscoelastic specimens, parts 3 and 5, are cylinders mounted in parallel inside the preload device composed of parts 1, 2, 4 and 6, as shown in fig. Due to a horizontal ground excitation the viscoelastic plate is exposed to a shear loading. Francis shangrila place, mandaluyong city, philippines. Pdf evolutionary model of viscoelastic dampers for. Pdf design and implementation of tuned viscoelastic. The present paper concerns the development of a new rather inexpensive frictionviscoelastic damper and its application in a damping system for base isolation of a structure. Viscoelastic ve dampers are one of the most common earthquake mitigation devices. In this paper, tests on viscoelastic ve dampers are carried out, and the results indicate that ve dampers have high energy dissipation capacity and excellent antifatigue properties. The preload is obtained by screws that compress the specimens by a quantity. This paper is intended to introduce the results of the experiment and provide an overview of the product. These tuned mass dampers are in general less costly than the more commonly used tmds employing viscous. Viscoelastic dampers veds are one of the most common passive control devices used in new and.
International journal of machine tools and manufacture. Various methods to design this kind of dampers have been proposed based on the desired level of additional damping, eigenvalue assignment, modal strain energy, linear quadratic. Dampers are components that counteract and often isolate the vibration source from the rest of the design or machine to prevent damage. This paper addresses the mathematical modelling of ve dampers and the dynamic analysis of structures with ve damp. Review on viscoelastic materials used in viscoelastic dampers.
Simple viscoelastic dampers have been invented for use on the root attachments of turbomachine blades. Energy dissipation dampers free download as powerpoint presentation. Modeling of a viscoelastic damper and its application in structural control. Previous studies have shown that fractional derivative models present a plausible level of accuracy when it comes to capturing the behavior of viscoelastic dampers due to being capable of expressing the effects of excitation frequency and ambient temperature in viscoelastic damper parameters. Damping, as a method to reduce unwanted vibrations, is most effective in cases where the vibratory system is excited with a frequency close to its natural frequency. Design and implementation of tuned viscoelastic dampers for. Fluid viscous damper is composed of a piston head, a piston rod and a cylinder full of a viscous fluid. Fluid viscous damper that operates according to the. Modeling of a viscoelastic damper and its application in. The typical viscoelastic damper consists of viscoelastic layers bonded with steel plates or solid thermoplastic rubber sheets sandwicthed between steel plates. Correlation coefficients for structures with viscoelastic dampers. Read our latest whitepapers to learn more about the industry and latest innovations from sorbothane. A feasibility study on precompressed partially bonded.
Life cycle testing of viscoelastic material for hubble space. Design and implementation of tuned viscoelastic dampers. Some practical issues associated with the application of viscoelastic ve dampers to building structures for seismic performance enhancement are studied in this paper. The solid viscoelastic dampers are among such passive energy dissipation systems. The damper can easily be manufactured and installed in a short time. Chang 5 viscoelastic materials are highly influenced by parameters like temperature. This paper presents an analytical model for predicting the hysteretic behavior of viscoelastic dampers based on the boltzmanns superposition principle and the method of reduced variables. In the rubbery region, the material reaches a lower plateau in stiffness. This paper investigate the performance viscoelastic dampers under explosive loading, through presenting the. Structural dampers viscoelasticity mechanical engineering. Read our whitepaper to learn more about the features of mechanical, pneumatic, hydraulic, and elastomeric material dampers.
Influence of damping systems on building structures subject to seismic effects proceedings of the ninth international conference on civil and structural engineering computing, egmondaanzee, the netherlands, september 2003. This paper addresses the mathematical modelling of ve dampers and the dynamic analysis of. To examine the response reducing effectiveness of these dampers, it is necessary that engineers are able to conduct response analysis of structures installed with added dampers accurately and efficiently. Use of viscoelastic dampers in reducing wind and earthquake. Oct, 2018 viscoelastic ve dampers, with their stiffness and energy dissipation capabilities, have been widely used in civil engineering for mitigating windinduced vibration and seismic responses of structures, thus enhancing the comfort of residents and serviceability of equipment inside. In recent years, numerical tools such as finite element method have been utilized to optimize the structure of ve rubber damper devices 9, 10. The viscoelastic materials generally used are copolymers or glassy substances.
Damping dissipation viscoelastic dampers reduce vibrations by converting kinetic energy into heat thus damping the motion of the system. Earthquake mitigation study on viscoelastic dampers for. Parameters of viscoelastic dampers can be obtained directly using the proposed method. Viscoelastic damper has been long used in vibration control of structures. Mahmoodi, design and analysis of viscoelastic vibration dampers for structures, in proc. Seismic design of viscoelastic dampers for structural.
Also viscoelastic dampers are often used in base isolation systems, see e. Modeling of viscoelastic dampers for structural applications. Separate elongate nonextensible outer plates are secured to opposite sides of the body in spaced. In suppressing vibrations, these dampers reduce fatigue thereby prolonging blade lifetimes while reducing. Correlation coefficients for structures with viscoelastic. Viscoelastic dampers are frequently used to protect tall structures against vibration. Continuous improvements in the techniques of identification and analysis, in fact, paralleled by noticeable refinements of device hardware, made the use of viscoelastic dampers. These arrays were built with viscoelastictitanium dampers, integral to the supporting masts, which reduce the interaction of the wing bending modes with the telescope. Dampers viscoelastic tuned mass dampers tmds use viscoelastic ve material as the suspension element, in such a way that the material exhibits the functionality of both the energy dissipation device viscous and the restoring device elastic. Some examples of these phenomena are discussed in this section1. This project deals with the study of behavior of the building with viscoelastic dampers, making it earthquake resistant.
Jul 11, 2018 viscoelastic dampers veds are one of the most common passive control devices used in new and retrofit building projects which reduce the structure responses and dissipate seismic energy during an earthquake. The present paper concerns the development of a new rather inexpensive friction viscoelastic damper and its application in a damping system for base isolation of a structure. A design method of viscoelastic damper parameters based on the. The purpose of the app is to compute and analyze the important parameters of the damper such as the hysteresis loop and. The mechanical properties of the viscoelastic damper made of high. To clarify the mechanical properties of ve dampers, a new mathematical model, named the equivalent fractional kelvin model, which considers temperature and.
The temperature scanning tests were carried out by a rheogele4000dma analyzer and the results showed the modulus and loss factor of viscoelastic damping material. Pdf performance of viscoelastic dampers under explosive. Comparative analysis of a multistorey building with and without. Omid ranaei and ali akbar aghakouchak, a new hybrid energy dissipation system with viscoelastic and flexural yielding strips dampers for multilevel vibration control, archives of civil and mechanical engineering, 10. The viscoelastic solid materials are used as a means to dissipate energy in viscoelastic dampers. Viscoelastic damper, metallic damper, tuned mass damper and friction damper etc. A material selected to exist in this region is ideally suited for such devices as isolators or tuned mass dampers because the modulus varies only slightly with changes in temperature and frequency. Influence of damping systems on building structures subject. The test was conducted on an electrohydraulic servo. Viscoelastic structural damper comsol multiphysics. It is concluded that connecting the two adjacent baseisolated buildings with the viscoelastic dampers is useful in controlling large bearing displacements in the base. Pdf performance based placement of viscoelastic dampers in an.
With the goal of developing impactful infrastructures and buildings that meet safety requirements for withstanding lowfrequency vibrations, viscoelastic structural dampers are a valuable resource to designers. The model parameters have physical meaning and they can be determined from simple timedomain and frequencydomain tests. The sevenparameter fractional derivative model is modified with the temperaturefrequency equivalent principle and utilized to describe the dynamic properties. In past relevant research, most analytical models for characterizing the mechanical behavior of ve dampers were. Passive means of vibration attenuation have been employed successfully and efficiently in machining systems such as turning and milling. The fractional zener model is used to describe properties of the viscoelastic body while the friction damper is modelled by the coulomb friction law in a setvalued form. Vicodas viscoelastic dampers are designed in a way that they can be used in a wide.
This application studies a forced response of a typical viscoelastic damper. Equivalent fractional kelvin model and experimental study on. Introduction damped outrigger concept to mitigate wind vibrations in tall buildings the st. These arrays were built with viscoelastic titanium dampers, integral to the supporting masts, which reduce the interaction of the wing bending modes with the telescope. Through the procedure, the dampers are placed one by one in stories with maximum interstory drift at each sequence. Performance based placement of viscoelastic dampers in an r. A sequential procedure is developed for optimally placing ve dampers to structures, based on the concept of degree of controllability. Pdf viscoelastic dampers utilize high damping from viscoelastic materials to dissipate energy through shear deformation. Viscoelastic tuned mass dampers tmds use viscoelastic ve material as the suspension element, in such a way that the material exhibits the functionality of both the energy dissipation device viscous and the restoring device elastic. Various methods to design this kind of dampers have been proposed based on the desired level of additional damping, eigenvalue assignment, modal strain energy, linear quadratic regulator. Viscoelastic damper connected to adjacent structures. In the present paper, several dynamic properties tests of the viscoelastic damper at.
Seismic analysis of structures with a fractional derivative model of. When viscoelastic dampers are used, the force f i t at a generic instant t 0 depends in principle on the whole time history of the associated deformation d i s l i y s, with 0. In the design of many structures, a particular area of concern is exposure to seismic and windinduced vibrations. Viscoelastic ve dampers, with their stiffness and energy dissipation capabilities, have been widely used in civil engineering for mitigating windinduced vibration. The damper properties are designed with reference from literature papers by m. This structure is composed of the primary coretube, suspended segments regarded as suspension systems, viscoelastic dampers and flexible layers. Reducing vibrations with viscoelastic structural dampers. Considering the possibility of earthquake occurrence during a structure lifetime. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. This damper represented a benchmark damper as its configuration was similar to the conventional viscoelastic dampers. Numerical examples on two common viscoelastic dampers demonstrate the advantages of the smm over fractional derivative and powerlaw models. Model, tests and application design for viscoelastic dampers zhao. Seismic response of structures with added viscoelastic dampers. Viscoelastic ve dampers have been successfully incorporated in a number of tall buildings as a viable energy dissipating system to suppress wind and.
Author links open overlay panel amir rashid a cornel mihai nicolescu b. The common feature is that the frequency of the forced vibrations is low. Analyze the design of a viscoelastic structural damper. Viscoelastic dampers veds are one of the most common passive control devices used in new and retrofit building projects which reduce the structure responses and dissipate seismic energy during an earthquake. The model parameters have physical meaning and they can be determined from simple timedomain and. An alternative practical design method for structures with. In the last decades viscoelastic dampers have been successfully used with the aim of mitigating the structural vibrations induced by natural actions, such as seismic motions, wind gusts, or ocean waves. Frontiers properties tests and mathematical modeling of. Study on mechanical properties of high damping viscoelastic dampers.
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