The nonlinear energy sink (NES) is a vibration control device that utilizes the nonlinear resonance between an auxiliary mass and the primary structure. By exploiting nonlinear restoring forces, NES can maintain its vibration reduction performance even when the natural period of a building deviates from design value. Among various types of NES proposed, challenges remain in ensuring sufficient restoring force under small displacements and enabling control in two horizontal directions. We proposed a bidirectional NES with pretensioned springs (PB-NES) that addresses these challenges by employing pretensioned tensile springs to secure restoring force under small displacements, and by introducing a dual-carriage mechanism to achieve simultaneous bidirectional control. Numerical analyses and shaking table tests using scaled models confirm that the proposed PB-NES provides effective control in two horizontal directions and exhibits robustness against variations in the natural period of the structure.
WADA et al. (Thu,) studied this question.