The viscoelastic materials generally used are copolymers or glassy substances. Pdf frame structures with viscoelastic ve dampers mounted on them are considered in this paper. Therefore, the amount of normal strain of each specimen is. Fluid viscous damper that operates according to the. The combined system often has a higher damping level and thus reduces the unwanted vibration inman 1996. There is no comparison between the results obtained for different models of dampers. Viscoelastic materials have been used in passive suspensions of heavy and light machines such as combustion engines, hard disks, bridges, large panels and other applications lakes, 1998. Chang 5 viscoelastic materials are highly influenced by parameters like temperature. Mahmoodi, design and analysis of viscoelastic vibration dampers for structures, in proc. New installation scheme for viscoelastic dampers using cables hyunhoon choi and jinkoo kim abstract. A number of studies have been carried out to investigate the performance of viscoelastic dampers veds and magnetorheological dampers mrds in controlling the seismic response of buildings, but very few of them regarding the effect of.
This research is an effort to develop an efficient method of design and easy implementation of tuned viscoelastic dampers tvds to control vibration in a milling process. Dynamic analysis of frames with viscoelastic dampers. 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. In this study a procedure for determining the optimum size and location of viscoelastic dampers is proposed using the eigenvalue assignment technique. Ve damping system in twin towers is a doublelayer shear damper using a 3m material, which is a.
Structural dampers free download as powerpoint presentation. Due to a horizontal ground excitation the viscoelastic plate is exposed to a shear loading. Influence of damping systems on building structures. Viscoelastic ve dampers have been successfully incorporated in a number of tall buildings as a viable energy dissipating system to suppress wind and. Optimal design of viscoelastic dampers in frame structures. They can be used in intake, exhaust, or mixed air applications.
In suppressing vibrations, these dampers reduce fatigue thereby prolonging blade lifetimes while reducing. 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. Viscoelastic attributes of a realistic damper can be described by a combination of springs and ideal viscous dampers. The properties of viscoelastic dampers, such as the possibility of energy. In the past, several rheological models were proposed for describing the dynamic behaviour of ve dampers and materials.
The viscoelastic solid materials are used as a means to dissipate energy in viscoelastic dampers. In order to investigate and check the actual behavior of viscoelastic dampers installed at piping systems and subjected to severe earthquake motions, a shaking table test with fullscale piping and viscoelastic dampers was carried out. Reducing vibrations with viscoelastic structural dampers. The solid viscoelastic dampers are among such passive energy dissipation systems. Kelvinvoight model a spring and a viscous damper in parallel is commonly used to characterize dashpots at a single frequency. Furthermore, the optimal placement of dampers is sensitive to the nature of excitation force, total quantity of viscoelastic material used, and the modeling of veds. Comparative study on the efficiency of friction and viscoelastic dampers. Comparative study of viscoelastic seismic damping systems. The evaluation of steel frame structures with viscoelastic.
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. 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. Modeling of a viscoelastic damper and its application in structural control article pdf available in plos one 126 june 2017 with 299 reads how we measure reads. These tuned mass dampers are in general less costly than the more commonly used tmds employing viscous. Modeling of viscoelastic dampers for structural applications. It is the aim of this paper to compare the dynamic.
Frontiers properties tests and mathematical modeling of. The system is assumed to be elastic and responses of the system are obtained in frequency domain for stationary random seismic excitations. Regarding the experiment, we report the results of an evaluation of seismic resistance against input in an. Index terms dampers, seismic evaluation, steel frames, viscoelastic. Use of viscoelastic dampers in reducing wind and earthquake. Energy dissipation properties of viscoelastic dampers are affected by frequency. Jun 01, 2017 modeling of a viscoelastic damper and its application in structural control article pdf available in plos one 126 june 2017 with 299 reads how we measure reads. A novel viscoelastic damping treatment for honeycomb sandwich. 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.
Damping dissipation viscoelastic dampers reduce vibrations by converting kinetic energy into heat thus damping the motion of the system. Passive energy dissipation devices, such as, viscous, viscoelastic, and friction devices are generally installed in buildings using diagonal or chevron braces. The seismic performance of viscoelastic dampers is greatly affected by viscoelastic materials. These dampers suppress bending and torsionmode blade vibrations, which are excited by unsteady aerodynamic forces during operation. Design and implementation of tuned viscoelastic dampers. Francis shangrila place, mandaluyong city, philippines. I created a model of a segment of cartilage tissue in abaqus. The typical viscoelastic damper consists of viscoelastic layers bonded with steel plates or solid thermoplastic rubber sheets sandwicthed between steel plates. 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 such excitations. Pdf dynamic analysis of frames with viscoelastic dampers. Hybrid structural control using viscoelastic dampers and active control systems hybrid structural control using viscoelastic dampers and active control systems tzan, shyh. Biological tissues are primarily viscoelastic in nature, meaning that their mechanical behavior, i.
Shaking table tests of a piping system with viscoelastic. Modeling of a viscoelastic damper and its application in. In recent years, viscoelastic dampers veds have been widely used in. The evaluation of steel frame structures with viscoelastic dampers.
In particular, the effect of ve dampers model on the behaviour of a structure with dampers as a whole is. 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. Evaluation of performance of viscoelastic dampers in. As a consequence of the viscoelastic nature of rubbers, their dynamic behavior is significantly dependent on frequency, temperature and strain level. Simple viscoelastic dampers have been invented for use on the root attachments of turbomachine blades. Viscoelastic ve dampers are dependent on both relative velocity and displacement to dissipate energy. A novel viscoelastic damping treatment for honeycomb sandwich structures.
A procedure for the parametric identification of viscoelastic. In the design of many structures, a particular area of concern is exposure to seismic and windinduced vibrations. Development of a viscoelastic tuned mass damper for floor. 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. Implementation of abaquss viscoelasticity modeling in a.
These tuned mass dampers are in general less costly than the more. Constrained layer dampers cld are in widespread use for passive vibration damping, in. This design and development process employs an analytical tvd model in combination with experimental dynamic model of a workpieceworkholding system, i. Viscoelastic damper, metallic damper, tuned mass damper and friction damper etc. Influence of damping systems on building structures subject. College of engineering, mathematics and physical sciences, university of exeter, exeter ex4 4qf, uk. Viscoelastic damper has been long used in vibration control of structures. Dynamic properties of structures with dampers modelled. Introduction damped outrigger concept to mitigate wind vibrations in tall buildings the st. They have proven to reduce vibration and shock problems in electronics, appliances, automobiles and aircraft. This paper is intended to introduce the results of the experiment and provide an overview of the product. Pdf performance based placement of viscoelastic dampers in an. 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. Implementation of abaquss viscoelasticity modeling in a cartilage tissue simulation alexia stylianou 1.
Use of viscoelastic dampers in reducing wind and earthquakeinduced motion of building structures. 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. Durg abstractan increase in the frequency of occurrence of natural disaster events like earthquakes has been evident over the past few years. It is shown that the scheme of the optimal placement of veds provides more reduction in response compared with other schemes of placement of veds considered in the study.
Theoretical and experimental study of viscoelastic damper. Also viscoelastic dampers are often used in base isolation systems, see e. Optimal vibration control of adjacent building structures. Veds take advantage of shear deformation of viscoelastic materials vem. Vicodas viscoelastic dampers are designed in a way that they can be used in a wide. Natural frequencies and modal damping ratios, required. The damper properties are designed with reference from literature papers by m. Optimal use of viscoelastic dampers in building frames for. Pdf this paper concentrates on assessing how the variation of placement and number of dampers affect the structural responses of a building. 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. Review on viscoelastic materials used in viscoelastic dampers. An installation scheme for viscoelastic dampers on bridge piers is proposed, and the mechanical models of the damper are analyzed according to the installation scheme.
In the rubbery region, the material reaches a lower plateau in stiffness. Hybrid structural control using viscoelastic dampers and. A novel viscoelastic damping treatment for honeycomb. 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. I utterworth iie i n e m a n n 0141029695000348 engineering structures, vol. Optimal design of viscoelastic dampers using eigenvalue. Samali graduate school of engineering, universi of technology, sydney, po box 123, broadway, nsw 2007. Structural dampers viscoelasticity mechanical engineering. The feasibility of using viscoelastic dampers to mitigate earthquakeinduced structural response is studied experimentally. Hvac control dampers commercial control dampers are used in buildings to regulate the flow of air in an hvac system.
Fluid viscous damper is composed of a piston head, a piston rod and a cylinder full of a viscous fluid. 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. Seismic behavior of posttensioned concrete bridge piers with. Relationship between viscous and viscoelastic dampers a common and effective way to reduce transient and steady state vibration is to add a layer of viscoelastic material, such as rubber, to an existing structure. New installation scheme for viscoelastic dampers using cables. Test procedure and determination of model parameters are also discussed. The sevenparameter fractional derivative model is modified with the temperaturefrequency equivalent principle and utilized to describe the dynamic properties. This technology is widely spread in nuclear power since 80s of the last century, 1 and 2. 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.
There are two categories of control dampers commercial volume control dampers and balancing dampers. Pdf modeling of a viscoelastic damper and its application. See 3m data sheet for dynamic mechanical properties of isd 830 viscoelastic. Feb 02, 2014 we use your linkedin profile and activity data to personalize ads and to show you more relevant ads.
The present paper addresses the theoretical and experimental studies of the viscoelastic. L for n viscoelastic dampers was put on the market by negurosu denko co. The preload is obtained by screws that compress the specimens by a quantity. Aug 20, 2014 in the design of many structures, a particular area of concern is exposure to seismic and windinduced vibrations. Viscoelastic dampers are energy dissipation devices of passive type, frequently used to mitigate excessive vibration of structures due to winds or earthquakes. The model parameters have physical meaning and they can be determined from simple timedomain and frequencydomain tests. Design and implementation of tuned viscoelastic dampers for. This paper investigates the seismic performance of posttensioned concrete piers with external viscoelastic dampers to improve the energy dissipation capacity of this type of structure. Development of a viscoelastic tuned mass damper for floor vibration applications, australian structural engineering conference, melbourne, vic. Pdf viscoelastic dampers utilize high damping from viscoelastic materials to dissipate energy through shear deformation. The damper can easily be manufactured and installed in a short time. The purpose of the app is to compute and analyze the important parameters of the damper such as the hysteresis loop and loss and storage moduli for a prescribed material model. Seismic response of structures with added viscoelastic dampers.