Adaptive negative stiffness device is one of the promising seismic protection devices since it can generate seismic isolation effect through negative stiffness when it is mostly needed and achieve similar vibration mitigation as a semi-active control device. However, the adaptive negative stiffness device generally combined with linear viscous damping underpins the drawback of degrading the vibration isolation effect during the high-frequency region. In this paper, a modified adaptive negative stiffness device (MANSD) with the ability to provide both lateral negative stiffness and nonlinear damping by configuring linear springs and linear viscous dampers is proposed to address the above issue. The negative stiffness and nonlinear damping are realised through a linkage mechanism. The fundamentals and dynamic characteristics of a SDOF system with such a device are analyzed and formulated using the Harmonic Balance Method, with a special focus on the amplitude–frequency response and transmissibility of the system. The system with damping nonlinearity as a function of displacement and velocity has been proven to have attractive advantages over linear damping in reducing the transmissibility in the resonance region without increasing that in the high-frequency region. The effect of nonlinear damping on suppressing displacement and acceleration responses is numerically verified under different sinusoidal excitations and earthquakes with different intensities. Compared with linear damping, the MANSD with nonlinear damping could achieve additional reductions on displacement and acceleration under scaled earthquakes, especially intensive earthquakes.

中文翻译：

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用于结构抗震保护的变负刚度和几何非线性阻尼的改进自适应负刚度装置

自适应负刚度装置是一种很有前途的抗震装置，因为它可以在最需要的时候通过负刚度产生隔震效果，并达到与半主动控制装置类似的减振效果。然而，自适应负刚度装置通常与线性粘性阻尼相结合，弥补了在高频区域降低隔振效果的缺点。在本文中，提出了一种改进的自适应负刚度装置（MANSD），它通过配置线性弹簧和线性粘性阻尼器来提供横向负刚度和非线性阻尼，以解决上述问题。负刚度和非线性阻尼是通过连杆机构实现的。使用谐波平衡法分析和制定了具有这种设备的单自由度系统的基本原理和动态特性，特别关注系统的幅频响应和传输率。已证明具有作为位移和速度函数的阻尼非线性的系统在降低共振区域的传输率而不增加高频区域的传输率方面比线性阻尼具有吸引人的优势。在不同的正弦激励和不同强度的地震下，非线性阻尼对抑制位移和加速度响应的影响进行了数值验证。与线性阻尼相比，具有非线性阻尼的 MANSD 可以在尺度地震下实现位移和加速度的额外降低，