Research On Response Characteristics Of Aging Status For Rubber O-ring Seal Structure

Rubber seal structure is widely used in the military and civilian fields of mechanical equipment.But in the long time storage and use of equipment,rubber seal material will occur aging phenomenon,so that the service performance of the structure degraded,and then affect the safety of the operation of mechanical equipment.Therefore,it is an urgent need of engineering practice to study the aging state detection method of rubber seal structure based on dynamic response signal and realize the non-destructive,online and quantitative detection of the aging state of the structure.In this paper,the change law of response characteristics of rubber O-ring seal structure under different aging states was researched based on the finite element method,which provides a theoretical basis and a priori knowledge for the research of non-destructive,online and quantitative detection method of structural aging states.The main work is as follows:(1)The finite element model of the experimental device of rubber O-ring seal structure was established by means of "modeling-leading-pretreatment".All pre-treatment processes are in line with the actual situation.By inputting different aging parameters of the same material,the purpose of different aging states of the equivalent model was realized,and the overall model meets the requirements of calculation accuracy and calculation time at the same time.(2)Using the established finite element model,the natural frequencies and modal mode shapes of the structure under different compression ratios and different aging states were calculated based on the finite element method.The change rule between the natural frequency and aging state of the structure was summarized.According to the finite element modal analysis results,the random vibration analysis and harmonic response analysis of the structure under different aging states were completed.The change rule between aging state and dynamic response peak of rubber O-ring seal structure was summarized.(3)By designing and building the experimental platform,the pulse excitation experiment and random excitation experiment of the experimental device were completed by using the acquisition software and control software.The modal parameters and their response parameters were extracted.The effectiveness of the structural finite element model was verified by comparing the finite element analysis results with the experimental results.The accuracy and reliability of the model were further improved by model modification.The results show that the finite element calculation results are consistent with the experimental extraction results,which verifies the analysis conclusion obtained in this paper: The natural frequencies and dynamic response peaks of the rubber O-ring seal structure increase with the aging degree of the structure.The finite element model of rubber O-ring seal structure established in this paper is accurate and reliable.The conclusions obtained can reflect the response characteristics and changes of the aging state of rubber O-ring seal structure,which can provides a theoretical basis for the non-destructive,online and quantitative detection method of its aging state.