橡胶密封圈粘弹特性研究

发布时间：2018-03-16 07:25

本文选题：薄壁法兰盘密封结构　切入点：超弹模型　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：飞行器整体油箱采用铝合金薄壁法兰盘密封结构,该密封结构常采用异形橡胶密封圈,如果设计合理、使用正确,在静密封中可以实现“零泄漏”,但现有的密封结构设计没有考虑粘弹效应在动、静密封工况下对密封性能的影响。本文结合粘弹效应和动、静密封工况,分析了密封圈的结构参数、材料参数、工况等对接触压力的影响,旨在对薄壁法兰盘密封结构在振动工况下的设计与开发提供理论与技术上的支持,本文的主要工作如下：(1)探讨了橡胶材料的超弹特性和单轴拉伸实验方法,测定了单轴拉伸试样在不同拉伸速率下的力-位移曲线,分析了相关的数据处理方法,并与有限元计算结果进行了比较；并且研究了不同超弹模型对材料实验数据的拟合精度。(2)探讨了橡胶材料的粘弹静态力学特性和材料粘弹应力松弛实验方法,测定了应力松弛实验试样在不同初始应变率下的力时间曲线,并分析了相关的数据处理方法,与有限元计算结果进行了比较。(3)探讨了橡胶材料的粘弹动态力学特性和动态力学分析(DMA)方法,对动态力学测试试样进行了不同温度下的扫频实验,获得了不同温度下复模量随频率的变化曲线,并分析了相关的数据处理方法。(4)在有限元软件中对超弹模型和粘弹松弛模型进行了叠加,对装配有橡胶密封圈的法兰密封结构的二维简化轴对称结构进行了瞬态动力学仿真,研究橡胶圈的结构参数(截面直径、截面形状)、间隙张开量、间隙张开时间、介质压力对密封性能参数(接触压力)的影响,对密封间隙回弹情况下法兰密封结构的前期设计提供指导。(5)使用粘弹动态特性复模量模型,对装配有橡胶密封圈的法兰密封结构的二维简化轴对称结构进行了瞬态动力学仿真,研究了温度、振动频率、振幅对密封性能参数(接触压力)的影响,对密封间隙低频小幅振动下法兰密封结构的前期设计提供指导。(6)分别基于超弹-静态粘弹松弛模型和动态粘弹复模量模型对飞机油箱三维结构进行瞬态动力学仿真；压缩松弛仿真研究了粘弹静态特性-松弛对接触压力的影响,为密封结构长期使用提供依据；通过有限元方法分析了不同温度下密封结构的抗振动能力。
[Abstract]:The integral fuel tank of the aircraft adopts aluminum alloy thin-walled flange sealing structure, the sealing structure often adopts special rubber seal ring, if the design is reasonable, the use is correct, Zero leakage can be realized in the static seal, but the existing seal structure design does not consider the effect of visco-elastic effect on the sealing performance under the condition of static seal. The influence of structural parameters, material parameters and working conditions of sealing ring on contact pressure is analyzed in order to provide theoretical and technical support for the design and development of thin-walled flange seal structure under vibration conditions. The main work of this paper is as follows: (1) the hyperelastic properties and uniaxial tensile test methods of rubber materials are discussed, the force-displacement curves of uniaxial tensile specimens at different tensile rates are measured, and the relevant data processing methods are analyzed. The results are compared with the results of finite element analysis, and the fitting accuracy of different superelastic models to the experimental data is studied. (2) the viscoelastic static mechanical properties of rubber materials and the experimental methods of viscoelastic stress relaxation of rubber materials are discussed. The force time curves of stress relaxation test specimens at different initial strain rates were measured, and the relevant data processing methods were analyzed. In this paper, the viscoelastic dynamic mechanical properties and dynamic mechanical analysis (DMA) method of rubber materials are discussed by comparing with the results of finite element method. The frequency sweep experiments of dynamic mechanical test samples at different temperatures are carried out. The variation curves of complex modulus with frequency at different temperatures are obtained, and the related data processing method. 4) superelastic model and viscoelastic relaxation model are superimposed in finite element software. The transient dynamic simulation of two-dimensional simplified axisymmetric structure of flange seal structure with rubber seal ring is carried out. The structural parameters (section diameter, section shape, gap opening amount, gap opening time) of rubber ring are studied. The influence of medium pressure on sealing performance parameters (contact pressure), which provides guidance for the pre-design of flange seal structure under the condition of seal clearance springback, using viscoelastic dynamic characteristic complex modulus model. The transient dynamic simulation of two-dimensional simplified axisymmetric structure with rubber seal ring was carried out. The effects of temperature, vibration frequency and amplitude on the sealing performance parameters (contact pressure) were studied. It provides guidance for the early design of flange seal structure under low frequency and small vibration of seal clearance. Based on superelastic-static viscoelastic relaxation model and dynamic viscoelastic complex modulus model, the transient dynamic simulation of aircraft fuel tank three-dimensional structure is carried out. Compression relaxation simulation is used to study the influence of viscoelastic static characteristics on contact pressure, which provides a basis for the long-term use of seal structures. The vibration resistance of seal structures at different temperatures is analyzed by finite element method.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V228.1;TQ336

【参考文献】