新型非线性超低频水平隔振系统的研制

通过对正负刚度并联隔振机理的分析，研制了新型正倒摆并联非线性超低频水平隔振系统。其正摆具有正刚度特性，倒摆具有负刚度特性。通过分析，得出了系统在平衡位置处的零刚度条件，系统水平刚度随两个摆长之比和下端弹簧刚度而变化的关系。试验研究表明：该隔振系统的固有频率由单一正摆时的1．75Hz降为0．5Hz，从而使其隔振频带加宽，隔振能力显著提高，而系统的结构保持较小尺寸。

Development of new typed nonlinear ultra-low frequency horizontal vibration isolation system

By means of the analysis on parallel vibration isolation mechanism of positive and negative stiffness, a new typed parallel nonlinear ultra-low frequency horizontal vibration isolation system with positive and inverse pendulums was developed. Its positive pendulum has characteristics of positive stiffness, and its inverse pendulum has characteristics of negative stiffness. By way of analysis, the zero stiffness condition of system at the equilibrium position and the relationship of systematic horizontal stiffness that varies with the ratio of lengths of two pendulums and with the stiffness of spring at lower end were obtained. The experimental study indicates that the natural frequency of this vibration isolation system dropped to 0.5 Hz from 1.75 Hz while with a single pendulum, thus broadened its vibration isolation band with a remarkable enhancement of vibration isolation ability but the structure of system was still kept in comparatively small dimensions.