In the equivalent water depth truncated model test design of a deepwater semisubmersible platform, the viscous damper is designed to simulate the contribution of mooring damping to total damping of floating platform. Kelvinvoight model a spring and a viscous damper in parallel is commonly used to characterize dashpots at a single frequency. Schematic drawings for typical configurations of double vane vwds are shown in appendix c. In this research, three 4, 8, 12storey steel structure frames were selected as the understudy models. This paper presents an application of fluid viscous dampers in a highrise structure to suppress the anticipated windinduced accelerations. Windows 2000, windows nt, windows xp the sap name has been synonymous with stateoftheart analytical. Pdf seismic performance of steel moment resisting frames with. Refer to the csi analysis reference manual for recommendations. Oct 18, 2014 for the love of physics walter lewin may 16, 2011 duration. Translational viscous damper with variable damping. The description of the damping system, the design criteria and cost data are discussed. Because the tenco seismic brake friction damper can be treated as an ideal elastoplastic element, this allows the application of wens model. Within all load cases of a certain type, damping is applied consistently, though additional damping may be added to individual load cases.
Modeling fluid viscous damper in etabs introduction to dampers. While a simplification of the dampers behavior, the wen model simplifies the analysis. Seismic design with friction dampers quaketek earthquake. A detailed and extensive procedure which describes the modeling, analysis, and design of a 3d steelframe pipe rack system. Maurer tuned mass and viscous dampers contents page 1. Damping technical knowledge base computers and structures. The damping properties of nonlinear viscous dampers are based on the maxwell model of viscoelasticity malvern, 1969, and may be specified for each deformational degreeoffreedom dof. Three kinds of devices are investigated in this paper.
Parameter calculation of viscous damper applied in the. Typical rubber damper configuration a crankshaft rubber damper is an example of a damped, tuned absorber. According to the etabs manual, the appropriate way to implement a viscous damper is through the elements with link property, see figure 331. A certain type of damping is available for each type of load case.
Statistics and matlab nonlinear link element for use with the dynamic time history analysis option link may be placed between any two joints or from joint to ground viscous damper with nonlinear exponent on velocity gap compression only hook tension only modelling of elements. Dec 15, 2017 this booklet provides guidelines for including dynamic isolation systems vwds in structural models of buildings subjected to earthquakes or wind. Nov 25, 2010 a relief valve parallel to the throttle valve is added to a velocity dependent hydraulic damper vdhd so that the orifice size that regulates the oil flow can be adjusted. My problem is for modelling the soil i had no clue how to assign transmitting boundaries for which i have brief idea now after reading the dialogue here. The viscous damper is modeled with a two node link element. To plot the results of the nonlinear analysis, you need to do a manual. Thus came into being dampers, viscous dampers of which its manufacturing process is. Viscoelastic attributes of a realistic damper can be described by a combination of springs and ideal viscous dampers. Click filenew menu or buttonicon to bring up the initial sap2000 screen where you select units and choose whether you want to work with grids or one of the templates. Guidelines and tutorial for modeling haunched steelgirder bridges.
The magnitude of the damping force is equal to the product of the physical signal input and the relative linear velocity between the two translational conserving ports. Most developments in the application of additional damping in bridges and buildings has occurred in the form of viscous fluid dampers, and the main approach is to maximise the high power. It also provides the basis for the nominal properties of these dampers and recommended property modification factor associated with the first cycle effect test. The translational damper block represents an ideal mechanical translational viscous damper, described with the following equations.
I am considering the bottom to be bed rock so the bottom will be fixed. Based on aerospace technology fluid viscous dampers have been proven in extensive tests at the multidisciplinary center for earthquake engineering research mceer at the state university of new york at buffalo. This device is a linear spring in series with a dashpot whose forcevelocity relationship exhibits bilinear viscous behavior, typical of certain oil dampers having a relief valve. Fluid viscous damper the viscous dampers are modeled as maxwell element, which is a nonlinear damper with a nonlinear spring. Evaluating effects of viscous dampers on optimizing seismic. Apr 10, 2010 how can i model pall friction damper in sap2000. A physical signal input port provides the magnitude of the translational damping coefficient. Numerical analysis of viscous wall dampers on steel frame. Other configurations, such as single vane vwds are also available. An additional advantage of the fluid viscous dampers was that the long period rubber bearings and fluid viscous dampers would be able to fully reset the building after a seismic event with no permanent offset. I want to model pall friction damper in sap 2000,but i dont know how.
Types of torsional dampers used rubber damper torsional viscous damper. Jun 22, 2014 damping, a property of the material and the structure, influences dynamic response. Vibratech tvd is a global leader in viscous damper manufacturing, engineering, and torsional vibration analysis for gas engines, diesel engines and powertrain applications. The viscous damper system proves to be a very costeffective method to reduce wind motions.
The single bay single story frame shown in figure 1 has 5000mm bay width and 3000mm story height. Additional information is available in the csi analysis reference manual chapter xv the linksupport element, nonlinear viscous damper. Adaptation of the tmd onto the main system structure 6 2. The block represents a translational viscous damper with variable damping coefficient. Viscous damping is caused by such energy losses as occur in liquid lubrication between moving parts or in a fluid forced through a small opening by a piston, as in automobile shock absorbers. A photograph of a typical damper at this facility is provided as figure 4. Sap2000 getting started tutorial csi knowledge base.
Study the impact of using viscous fluid dampers in steel buildings. The sides however have to be truncated and a viscous transmitting boundary has to assigned. Application of viscous damper in engineering yang huan school of southwest petroleum university, chengdu sichuan 60, china. Nonlinear viscous damping technical knowledge base. An idealized schematic of the model is presented in figure 1. The absorption of the seismic input energy in the buildings and reducing its damage are the main objectives of these devices. The energy lost per cycle in a damper in a harmonically forced system may be expressed as w d i f ddx 1 where f d represents the damping force. Viscous damping is a common form of damping which is formed in many engineering systems such as instruments adn shock absorbers. Jun 21, 2014 a bilinear maxwell damper has been implemented as a new link property. Its a kind of friction damper that installed in x bracing systems and reduce earthquake effects on the structure. The viscous damping force is proportional to the first power of the velocity across the damper, and it always opposes the motion, so that the damping force is a linear continuous function of the velocity. Modeling of dis viscous wall dampers in sap2000, etabs.
It features a powerful graphical user interface that is unmatched in terms of easeofuse and productivity. A bilinear maxwell damper has been implemented as a new link property. For this tutorial, we will work with grids, but you will probably want to explore the quick brim options for modeling of simple bridges later on. Viscous fluid dampers for structural civil markets. A frictionspring hysteretic damper has been implemented as a new link property. F is the force exerted by the damper, c is the damping coefficient, v is the velocity of the damper. May 25, 2016 licensed to youtube by daredo gmbh music on behalf of harthouse mannheim. Tunedmass damper tutorials computers and structures.
Fluid viscous dampers to reduce windinduced vibrations in. Viscous fluid dampers for structural civil applications. The viscousdamping force is directly proportional to the relative velocity between the load next article. Dynamic analyses of 1story moment frame with viscous dampers. Jun, 2014 link objects are very well suited for modeling the nonlinear forcevelocity relationship of viscous damping.
Nov, 2014 for a seismic increased protection, new technologies have been developed, among these technologies there is the passive energy dissipation devices. Stiffness of damper element is considered zero in order to reach the pure damping in linear analyses. The viscous wall dampers discussed here are double vane dampers with a viscous fluid layer thickness of 5mm. Steel mrfs, linear and nonlinear fluid viscous damper, far field ground motion. In part 1 we defined a viscous damper as a fundamental component to create durability and efficiency in a powertrain system by reducing torsional vibration. To understand what torsional vibration is, we turn to aaron neyman, vibratech tvd snr. Each damper is 4,3 meters in length and weighs nearly 1500 kg. Seismic energy dissipation study of linear fluid viscous. This study will focus on the seismic design of structures with supplemental fluid viscous dampers device. Viscous damper system will be modelled as pure stiffnessfree damping behaviour. Practical application issues for the structural engineer by amy hwang b. To model a damper in sap 2000, a section of damper type is used. Study of nonlinear fluid viscous dampers behaviour in seismic.
Viscous damper in mechanical translational systems matlab. In other words, it is modeled as a fictitious yielding brace. This element follows a viscous damper hysteretic response. A tunedmass damper tmd, also known as a pendulum damper, is not really a damper, but rather a pendulum or another gravitybased oscillator which is attached to the structure in such a way that it counteracts the vibration of one or more fundamental modes, thereby reducing the wind andor seismic response of those modes. Compact, yet powerful, these dampers increase structural damping lev. Linear viscous damping linear viscous damping is a property of the computational model and is not a property of a real structure 19.
This device adjustment will allow the damper to have an adaptive control of damping by changing its damping coefficient. Viscous wall damper modeling guide civil engineering community. Seismic energy dissipation study of linear fluid viscous dampers in steel structure design. For the love of physics walter lewin may 16, 2011 duration. This tutorial provides an introduction to the assignment of joint patterns.