Low-frequency Vibration Reduction And Isolation Technology Under Conditions Of A Wide Range Of Load

With the higher and higher level of productivity and the deepening of supply-side reform,the demand for product precision in the industrial system is getting higher and higher,and products and instruments are gradually developing to precision.Among them,the disturbance of low-frequency mechanical waves mainly hinders the development of precision.The application of quasi-zero-stiffness(QZS)vibration isolator can achieve effective low-frequency vibration reduction and isolation.However,the load variation range of the existing QZS vibration isolator is small in the QZS stage,which does not take into account the large-scale load variation of the equipment.Therefore,in this paper,considering the large range of load variation of the equipment,two kinds of QZS vibration isolators which can adapt to the large range of load variation are studied and designed.First of all,the finite element models of two QZS structures with different design principles are established by using the finite element software ANSYS,.The first is a shell structure with a specific shape,and the second is the parallel structure.Then,in order to obtain two kinds of QZS structures with different design principles,the static nonlinear analysis of the shell structure with specific shape and the parallel structure with positive and negative stiffness elements is carried out by using the finite element software ANSYS,and the corresponding QZS shell structure and curved beam-spring parallel QZS structure are obtained respectively.The results show that the QZS shell structure has the characteristics of high static and low dynamic stiffness and a large range of QZS stage load,so it has the performance of low-frequency vibration reduction and isolation under a large range of loads.the curved beam-spring parallel QZS structure has small dynamic stiffness,large dynamic displacement and low-frequency vibration isolation performance under a certain range of load.After that,the QZS structures with two different design principles are optimized,and it is concluded that the load variation range of QZS structures in the QZS stage can be expanded.However,with the expansion of the range of load variation,the performance of low-frequency vibration isolation will be reduced.By comparing the two structures,it is concluded that the load variation range of QZS shell structure is much larger than that of curved beam-spring parallel QZS structure.In practical engineering,the use of a single QZS shell structure is greatly limited,and the series-parallel systems of multiple QZS shell structures are more widely used.Therefore,the static nonlinear buckling analysis of different series-parallel shell systems is carried out by using the finite element software ANSYS,and different series-parallel QZS shell systems are obtained.It is concluded that the load variation range of the series QZS shell system in the QZS stage is the union of the QZS shell in series,which can meet the demand of low-frequency vibration reduction and vibration isolation under a larger load variation range.the bearing capacity of the parallel QZS shell system increases in the QZS stage.Finally,the large deformation prestress modal analysis of the QZS shell structure is carried out by using the finite element software ANSYS,and the natural frequency and vibration mode of the QZS shell structure are obtained.Then,the large deformation prestress modal analysis of QZS shell structures with optimized geometric parameters and different pressure loads is carried out,and a series of natural frequencies and vibration modes of QZS shell structures are obtained.The results show that the QZS shell structure has a large load variation range in the QZS stage,and the optimization design of the QZS shell structure can make it have a larger load variation range in the QZS stage or better low-frequency vibration reduction and isolation performance.