Some questions of nonlinear seismic isolation behavior

DOI: 10.37153/2618-9283-2022-3-8-19

Authors:  
Rubric:     Theoretical and experimental studies   
Key words: seismic isolation, increasing stiffness, decreasing stiffness, phase plane, kinematic support, nonlinear operation
Annotation:
An analytical solution of the motion equation of nonlinear seismically isolated systems on the phase plane is obtained. The cases of systems with increasing and decreasing stiffness are considered. A typical example of a system with increasing rigidity is a system with restrictors. Systems with decreasing stiffness include well-known types of seismic isolation with kinematic supports of A.V. Kurzanov and Yu.D. Cherepinsky. For systems of the first type, the motion trajectories on the phase plane are always limited, but with strong displacement restrictions, an increase in accelerations takes place. The proposed solution makes it possible to analyze the dependence of the acceleration growth on the displacement limitation. Solutions of the second type can be unstable, which is clearly seen on the phase trajectories. This requires an analysis of their stability when designing seismic isolation. Used Books:

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