Summary
Nonlinear mechanisms leverage nonlinear kinematics to enhance the efficacy of isolators, maintaining controlled static deflections while keeping natural frequencies low. Despite extensive examination of their performance under harmonic base excitation, there is a scarcity of applications incorporating real seismic signals, and few experimental validations exist for real-world scenarios. This study substantiates the advantageous impact of High Static Low Dynamic Stiffness isolators vs. linear counterparts in diminishing transmitted vibrations to a suspended mass during near-fault earthquakes through experimental demonstrations. Additionally, a lumped parameter model is devised, incorporating a piecewise nonlinear-linear stiffness, and accounting for dissipation through viscous and dry friction forces. Preliminary tests encompass harmonic base motion scenarios to assess isolator transmissibility in various cases. The model exhibits outstanding agreement with experimental measurements.
