Quasi-zero stiffness vibration isolation device with mechanical frequency modulation type dynamic vibration absorber

Abstract

The invention discloses a quasi-zero stiffness vibration isolation device with a mechanical frequency modulation type dynamic vibration absorber. The vibration isolation device is formed by combining a quasi-zero stiffness vibration isolation main system and a dynamic vibration absorber subsystem; and a bearing platform, a negative stiffness mechanism and a dynamic vibration absorber are mainly comprised. On the basis of a traditional "spring-mass block" vibration absorber, a frequency-adjustable dynamic vibration absorber of a "spring plate-sliding mass block" structure is provided, four negative stiffness mechanisms are additionally arranged on the basis of a traditional linear main system, positive stiffness and negative stiffness are connected in parallel to form the quasi-zero stiffness vibration isolation main system, and the quasi-zero stiffness vibration isolation device with the mechanical frequency modulation type dynamic vibration absorber is designed. According to the vibration isolation device, the inherent frequency of the dynamic vibration absorber can be adjusted by changing the effective length of a spring plate, the limitation that a traditional dynamic vibration absorption device is only suitable for single excitation frequency is broken through, the excitation frequency application range can be widened, excitation frequency self-adaptability is achieved, the amplitude of the quasi-zero stiffness vibration isolation main system is reduced, and self-adaptive ultralow-frequency vibration isolation effect is achieved.

Description

technical field [0001] The invention relates to the technical field of ultra-low frequency vibration isolation, in particular to a quasi-zero-stiffness vibration isolation device including a mechanical frequency modulation dynamic vibration absorber. Background technique [0002] The dynamic vibration absorber is a spring-mass vibrator system composed of mass, spring, damping and other components. It is connected to the main system through elastic elements and damping elements, so that all the energy of the external excitation acting on the main system is transferred to the dynamic vibration absorber, so that the force of the dynamic vibration absorber acting on the main system and the external excitation acting on the main system The forces are equal in size and opposite in direction, so that the main system is in a balanced state and the vibration amplitude of the main system is reduced. Compared with other traditional vibration damping devices, the dynamic vibration abso...

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Problems solved by technology

Piezoelectric ceramic dynamic vibration absorbers have relatively high stiffness and require a relatively large vibrator. At the same time, piezoelectric ceramics cannot be stretched and are relatively brittle, so that the vibration amplitude of this dynamic vibration absorber will be very small, which limits the vibration absorption capacity. , and may cause system instability

Due to the temperature hysteresis nonlinearity of the shape memory alloy variable stiffness dynamic vibration absorber, the stiffness of the dynamic vibration absorber can be adjusted, but the temperature control of the shape memory alloy is very difficult, which increases the difficulty of stiffness adjustment; moreover, although the shape memory alloy variable stiffness dynamic The natural frequency of the vibration absorber can be adjusted, but it is discrete. Therefore, the continuous change of stiffness cannot be realized, and the adjustment range of its equivalent stiffness is also narrow.

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