In this paper, an innovative controllable negative stiffness system (CNSS) integrating adaptive negative stiffness and controllable damping characteristics is proposed to realise desirable vibration protection and improve adaptability, hence being effective to various earthquakes. The force-displacement relationship of the CNSS is derived as the forward model to describe its nonlinear properties. Three representative control algorithms, i.e., Linear Quadratic Regular (LQR) control, H∞ control and Sliding Mode (SM) control, are utilised for the CNSS to attain optimal control force. Based on the Takagi-Sugeno-Kang (TSK) Fuzzy inference system optimised by Non-Dominated Sorted Genetic Algorithm II (NSGAII), a novel inverse model is proposed accordingly to obtain input current according to the required control force and real-time system responses. To demonstrate the feasibility and efficiency of the CNSS for structural seismic protection, a numerical case study is conducted on a three-storey building model with CNSS installed on its first floor. Four scaled benchmark earthquakes are employed as excitations for the case study. Ten evaluation criteria are adopted to assess and verify the performance of the CNSS, and comparisons are made with that of uncontrolled and passive controlled systems. The numerical results indicate that the proposed CNSS can significantly improve the vibration control performance on all evaluation criteria simultaneously in comparison with the other two conventional systems. In addition to having good suppression effects on peak floor displacement and peak inter-storey drift, the CNSS with the SM controller demonstrates superior performance on mitigating peak structure shear and peak acceleration response of the first floor.

中文翻译：

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一种新型负刚度可控阻尼结构抗震系统

在本文中，提出了一种创新的可控负刚度系统（CNSS），它结合了自适应负刚度和可控阻尼特性，以实现理想的振动保护并提高适应性，从而对各种地震有效。推导出 CNSS 的力-位移关系作为描述其非线性特性的正向模型。三个有代表性的控制算法，即线性二次规则 (LQR) 控制、 H∼ 控制和滑动模式 (SM) 控制，用于 CNSS 来获得最佳控制力。基于由非支配排序遗传算法 II (NSGAII) 优化的 Takagi-Sugeno-Kang (TSK) 模糊推理系统，相应地提出了一种新的逆模型，根据所需的控制力和实时系统响应获取输入电流. 为了证明 CNSS 用于结构抗震保护的可行性和效率，对一个三层建筑模型进行了数值案例研究，CNSS 安装在其一楼。四个比例基准地震被用作案例研究的激励。采用十项评价标准对 CNSS 的性能进行评估和验证，并与非受控和被动受控系统进行比较。数值结果表明，与其他两种常规系统相比，所提出的 CNSS 可以同时显着提高所有评估标准的振动控制性能。除了对峰值楼层位移和峰值层间漂移有很好的抑制作用外，