دانلود رایگان مقاله انگلیسی کنترل پاسخ لرزه ای با میراگیر جرمی تنظیم شده بدون کشش - الزویر 2018

ABSTRACT

An elasto-plastic spring is utilized in a tuned mass damper (TMD) with eliminating its viscous damper to establish a new seismic response control system. A novel method to find the most appropriate parameters of the proposed elasto-plastic TMD (P-TMD) including its initial stiffness/frequency and yield strength is presented so as to reduce the seismic response of the main system with the P-TMD to a level of that obtained with a previously suggested optimum TMD. The parameters are used to compute the responses of several main structures in the form of single-degree of freedom systems with the proposed P-TMD under different earthquake excitations. To evaluate the effectiveness of the proposed device and tuning method, maximum displacements and accelerations are compared to those of optimum TMD systems as well as those obtained from uncontrolled ones. The numerical results show that the proposed device, when using the introduced procedure for selecting its design parameters, reduces the seismic responses significantly and can be used instead of the optimum TMD without the need for a viscous damper.

6. Conclusions

The present study can be summarized as follows:

• A new approach for seismic response control of structures with the elasto-plastic TMD (P-TMD), which consists of a mass and an elastoplastic spring without the need for a viscous damper, has been presented in this paper.

• A simple yet effective method to estimate the design parameters of the device was developed and applied to the structural systems subjected to the seismic excitations. The proposed procedure has resulted in the explicit formulas to compute the tuning and acceleration ratios of the device for a given set of mass and damping ratios of the main system so that the inelastic behavior of the P-TMD can be equivalent to the visco-elastic behavior of a given optimum TMD.

• For the purpose of comparative analysis, the suggested optimum TMD by Sadek et al. [12] was then considered as a reference TMD. Comparison of the energy responses of a structural system equipped with P-TMD and optimum TMD shows that hysteretic behavior of PTMD dissipates nearly the same energy as that dissipated by the viscous damper of TMD.