As a new type of non-linear vibration isolator, wire rope vibration damper
has a wide application prospect in vibration and noise control. However, at present, the theoretical analysis and experimental study of wire rope vibration dampers are still mainly focused on stiffness and damping, while the analysis of mechanical impedance is rare. As mechanical impedance and parameter identification technology is an effective means for modern analysis and research of mechanical and structural dynamics problems, and a new technology combining theoretical analysis with experimental research, it is more convenient and simple to adopt mechanical impedance technology than other methods in the design and evaluation of system vibration isolation and sound isolation. At the same time, the dynamic stiffness of wire rope vibration damper can only reflect the performance at low frequency, but can not be applied at high frequency. The noise of the structure is proportional to the product of the velocity of each point and its corresponding area, so the noise curve and the velocity admittance curve are basically the same. Therefore, it is very important to apply mechanical impedance method to the analysis of vibration isolation and sound isolation.
Generally speaking, when the wire rope vibration damper is used as a single-degree-of-freedom system for analysis, its mechanical model is a parallel structure of damper and spring. Among them, the damping part can be regarded as structural damping, and its loss factor is more than 0.2. The specific value depends on the length, strand number, diameter and winding mode of the wire rope. The elastic part has a non-linear property, and its rigidity coefficient is related to the magnitude of motion.