Study On Dynamic Characteristics Distribution Of Air-Floating Vibration Control System

In this thesis,the dynamic characteristics of air-floated vibration control system are studied by combining theoretical analysis,numerical calculation and field measurement verification of vibration control engineering,which provides design basis for the same type of air-floated vibration control system.Through the field vibration test of the air-floated vibration control system of the high and low temperature box of the actual micro-vibration control project,the actual vibration reduction efficiency of the air-floated vibration control system is obtained by timefrequency domain analysis and transfer function analysis of the test data.The finite element model is established by ANSYS software to analyze the modal,dynamic transient and harmonic response of the project.The numerical results are compared with the test results.The natural frequencies of the vertical vibration modes in the numerical analysis of the air-floated vibration system are basically the same as the fundamental frequencies of the system design.The acceleration time history curves obtained by the transient dynamic analysis and the acceleration time history curves of the test bench are changed.The trend is basically consistent,so it can be considered that the accuracy of the parametric finite element model established in this paper meets the requirements.Based on the above verified finite element model,the parametric finite element model of the air-floated vibration control system is established,considering the design simulation conditions of the platform size parameters that may be encountered in practical engineering.The finite element model of the air-floated vibration control system under multi-conditions is modal analyzed by changing the design parameters continuously,and the first six modal natural frequencies are extracted,and the multi-condition system is established.Secondly,the data in the database are sorted out and analyzed,and the formulas for calculating the first three modal natural frequencies of the air-floated vibration control system with respect to the design dimension parameters of the platform are fitted.Through comparison and verification,the first three order modal calculation formulas of air-floated vibration control system fitted in this paper have better accuracy for similar type air-floated vibration control system.Therefore,the research results of this paper can be used to calculate the natural frequencies of similar vibration isolation system and predict the general distribution of system modal,which can save a lot of time for designers to simulate repeatedly.In order to modify the formulas of the first three modes of the air-floated vibration control system proposed in this paper,so as to improve the calculation accuracy and reduce the error,the method presented in this paper can be applied to the study of other design parameters affecting the dynamic characteristics of the air-floated vibration control system.