جستجوی مقالات مرتبط با کلیدواژه « جداساز پایه » در نشریات گروه « عمران »

In this research, the behavior of concrete rectangular ground tanks equipped with lead-rubber base isolators has been investigated under the simultaneous excitation of transitional and rotational components of earthquakes, using nonlinear time history analysis including water-structure interaction. For this purpose, first, the rotational component of three earthquakes was generated using the wave propagation and classic elasticity theories simultaneously. Then, the tanks equipped with appropriate number of base isolators were modeled in two volumes of 500 and 1000 m3 and three states of water level. In modeling the finite elements of the isolators, a model consisting of one-dimensional elements is proposed; whose hysteresis behavior is equivalent to the behavior of the three-dimensional model of the isolators.The results of the research show that the decreasing or increasing effect of the rotational component of the earthquake on the seismic response of these tanks in the full and half-full state is less than 10%, and in general, its effect on the seismic response of the rectangular ground tanks can be ignored. Also, the presence of isolators in these types of tanks has increased the response of the tanks in all states. So that the base shear force has increased up to 4 times and the normal stress has increased between 8 and 23 times, which can be attributed to the increase in the period of ground tanks from the initial range of the response spectrum to the constant acceleration region of the spectrum due to the presence of the base isolators.

In this research, numerical analysis of the hybrid lead rubber bearing system with shape memory alloy was investigated by Abaqus software and the effectiveness of various parameters on its performance was examined. The parameters studied are the bearing dimensions, the type of shape memory alloy and its cross-sectional area, the lead core diameter, the thickness of the rubber layer and the compressive stress. In this hybrid bearing, memorable form shape memory alloy are used as a recovery unit and lead core is used as a unit of energy dissipation. For this purpose, a finite element model of the bearing is modeled using the Abaqus software and the effect of the various parameters mentioned on the bearing performance has been investigated. The results show that the structures equipped with this bearing have better seismic performance than lead rubber bearing. Finally, depending on what kind of performance is required from the bearing, the parameters can be obtained optimally. As a result, in order to achieve a combination of behavior, both the suitable absorption capacity of lead and the recentring property of the shape memory alloy, it is necessary to balance the stiffness between the lead core and the shape memory alloy wire.