مقاله انگلیسی رایگان در مورد کنترل پاسخ لرزه ای با میراگر جرمی – الزویر 2018

The tuned mass damper (TMD) is a typical passive control device attached to the main system with the goal of reducing vibrations of mechanical and structural systems under the action of external loads. This device consists of a mass, a spring and a viscous damper which all should be selected properly according to the properties of the main system and the applied loads. Because of its simple and reliable implementation, TMD has been widely used and studied. Effectiveness of TMDs depends on their properties, such as mass ratio, frequency and damping ratios, hence various studies have been carried out to obtain the optimal parameters of these devices. Den Hartog [1] derived closed-form expressions for the optimum TMD parameters for undamped single-degree-of-freedom (SDOF) main systems under harmonic external forces. Simple expressions for optimum TMD parameters are also derived by Warburton [2] for undamped main systems subjected to external forces or support accelerations in the forms of harmonic and white noise random excitations. The effect of light damping in the main system on the optimum parameters of the TMD has also been investigated in [2] for random excitations and in [3,4] for harmonic force excitations. Tsai and Lin [5] developed a numerical searching procedure to find the optimum tuning frequency and damping ratio of the TMD for minimizing steady-state response of damped main systems subjected to harmonic support motions. In addition to harmonic excitations, the effectiveness of TMDs for wind loads has also been confirmed by several investigations [6–8]. Performance of single TMD systems, however, in structures subjected to earthquake loads, which possess many frequency components, is expected to be different and to depend on the ground motion properties [9–11]. While effectiveness of a TMD will be greatest when a real structure with a number of degrees of freedom oscillates around a predominant mode, this device does not reduce the structural response to a great extent when several modes contribute significantly to the main system response. Nevertheless, several successful studies have been devoted to improve the seismic performance of TMDs in different structural systems [12–16]. The well-known high modal damping criterion was used by some researchers such as Sadek et al. [12] and Miranda [13,14] to determine the optimum parameters of TMDs for the purpose of seismic response reduction. Some other criteria (or objective functions) have also been considered for this purpose [15–18]. Most of the studies on TMDs including those discussed above have employed the devices with elastic springs and linear behavior. However, the nonlinear behavior in TMDs has been considered for more effective control of unwanted vibrations in some investigations. The nonlinearity can be achieved with some simple implementation of practical engineering options such as combined action of several elastic and linear springs coming into action sequentially [19], equipping with friction-spring elements [20], using nonlinear viscous damping elements [21], and using Duffing spring for stiffness element of TMD [22,23]. Contrary to these sources of nonlinearity, here the nonlinear behavior of a TMD arising from inelastic behavior of its spring is of particular interest.