Viscoelastic Behavior Research On Rubber Seal Ring

Aircraft tank uses aluminum alloy thin-wall flange plate structure as its sealing structure, if designed reasonably and used right, the seal structure can realize "zero leakage" in the static seal. But it didn’t consider the viscoelastic effect on the performance of sealing under dynamic and static sealing conditions in the design of the existing sealing structure. Based on the viscoelastic effect and working condition, this paper analyses the influence factor of contact pressure, such as sealing ring structure with different parameters, material parameters and working conditions to provide theoretical and technical support for thin-wall flange sealing structure in the design and the development of the vibration condition. In this paper, the main work is as follows:(1) The hyper-elasticity properties of rubber materials and the uniaxial tensile experiment method have been discussed. Uniaxial tensile samples were measured for force-displacement curve under different tensile rates. Related data processing method was analyzed. Uniaxial tensile experiment results were compared with the finite element calculation results. And different hyper-elasticity model on the fitting precision of the materials experimental data were studied.(2) The viscoelastic static mechanical properties of rubber materials and stress relaxation experiment method have been discussed. The stress relaxation experiment samples under different initial strain rate were measured for force-time curve. Related data processing method were analyzed. The stress relaxation experiment results were compared with the finite element calculation results.(3) The viscoelastic dynamic mechanical properties of rubber materials and dynamic mechanical analysis (DMA) method have been discussed. Frequency sweep experiment has carried on under different temperature. The complex modulus curves along with the change of frequency under different temperature were obtained.(4) The hyper-elasticity model and the viscoelastic relaxation model have been superposed in FEA software. Transient dynamics simulation has been carried out to analyse the two-dimensional axisymmetric simplified structure of flange sealing structure equipped with rubber sealing ring. Influence of the structure parameters of rubber ring (section diameter, cross section shape), open content, open time gap clearance and pressure on the contact pressure, the sealing performance parameters, was studied to provide guidance in the early stage of flange seal structure design under seal clearance process conditions.(5)Considering complex modulus model with viscoelastic dynamic characteristics, transient dynamic simulation has been carried out to analyse the two-dimensional axisymmetric simplified structure of flange sealing structure equipped with rubber sealing ring. Influence of temperature, vibration frequency and amplitude on the contact pressure, seal performance parameters, was studied to provide guidance in the early stage of flange seal structure design under low-frequency small vibration condition of seal clearance.(6) Based on the hyper-elasticity-static viscoelastic relaxation model and dynamic model of viscoelastic complex modulus, transient dynamics simulation on three-dimensional structure of the aircraft fuel tank were carried out. Compression relaxation simulation was carried out to study the static relaxation effect on the contact pressure, which provided basis for long-term use of sealing structure. FEA on vibration analysed the vibration resistance of the sealing structure under different temperature.