The Study On The Dynamic Character Of Rolling Base Isolated Structure

Base isolation is an effective way to protect structures from damage in severe earthquake. It can ensure the safety of people's lives and properties. Rolling isolation is one form of base isolation. It has the characteristics of good stability, function of restrict displacement and restoration and prominent islation effect, etc. Now, there has been a few theoretical study on its dynamic performance. Owing to its difficulty, many technique criterion to guide the design of rolling structure is absent in our country. So it is of great theoretical and engineering significance to study rolling structure in this paper. The main contents studied in this paper are as follows: Firstly, two kinds of isolation devices are introduced: rolling spheres with re-centering isolation device and rolling spheres with concave-board isolation device. The way of combining MATLAB program and SIMULINK emluator is presented, which can solve dynamic equation of rolling base isolation structure. Secondly, dynamic equations of two kinds of isolation devices are established and the response of two kinds of isolation structures under the action of harmonic wave and earthquake are simulated and analyzed respectively. The results show that shock absorption difference is small and rolling spheres with concave-board isolation structure restricts the base displacement more effectively, furthermore the orientation of steel spheres is more convenient and reliable. Thirdly, a new type rolling base isolation system, i.e, rolling spheres with concave-board and re-centering isolation device is presented, computing model and dynamic equation of the isolation system are established. The numerical results show that the isolation structure can not only better absorb shock, but also control the base displacement effectively. It's applicable to all kinds of earthquake and its general performance excels frontal introductive two kinds of isolation devices. Finally, the decision variables R , k b, μ0and b are presented. The influences of different variables on the dynamic performance of the isolation structure are analyzed and the variables are optimized.