Dynamic Response of a Pendulum Isolator System under Vertical and Horizontal Earthquake Excitation

The paper studies a pendulum isolator. This isolator has a spherical surface which is placed on the foundation and it has an arm which is connected to the column of the building as a hinge. When the height of the arm is less than the curvature radius of the spherical surface, and a small movement is applied on it, a restoring force will be applied to the isolator. In this paper the eect of horizontal and vertical component of seismic load was studied. The dynamic equation of motion was obtained for the pendulum isolator under horizontal and vertical accelerations of seismic loads. The equation was solved by step time integration method. The comparison of the results of horizontal component eect and the combined eect of horizontal and vertical components on the isolator showed that the vertical component eect increased the isolator horizontal displacement response and increased the isolator horizontal acceleration.