O形密封圈的有限元力学分析

采用大型有限元分析程序 MARC/ Mentat32 0对 O形密封圈在“安装”状态和密封流体介质作用下的力学性能进行了分析 ,研究了造成密封圈撕裂损坏及材料松弛的当量 Cauchy应力峰值大小及位置随密封流体介质作用的变化情况 ,以及轴和密封接触面间的接触压力及剪应力分布状态。为重要场合下 O形密封圈的正确选用提供了一种方法。     

O形圈轴对称超弹性接触问题的有限元分析

本文采用罚单元接触算法,建立了O形橡胶密封圈的轴对称超弹性接触问题的非线性有限元分析模型,结合国际上通用的有限元分析系统ANSYS程序,对多种型号的O形圈进行了有限元分析,为橡胶密封件的设计计算提供了一条新途径。     

考虑温度影响的O形圈可靠性分析

针对O形圈处在高温工况容易发生热膨胀及应力松弛并导致失效的情况,利用有限元软件分析比较考虑温度时和不考虑温度时O形圈的应力及应力随着时间的松弛情况,并使用响应面法,计算出O形圈的剪切破坏失效、密封失效及多失效的可靠度。结果表明:高温对O形圈的应力分布和松弛速率的影响很大;O形圈的剪切破坏可靠度及泄漏失效可靠度随时间呈下降趋势,初期会发生急剧下降而后期下降速度减小;O形圈的多失效可靠度前期急剧减小然后基本达到稳定,表明O形圈在使用初期没有发生失效,则其在后期发生失效的概率较低。     

橡胶O形密封圈的非线性有限元分析

借助于大型非线性有限元分析软件MSC．MARC，建立了橡胶O形圈与沟槽接触的非线性有限元分析模型，分析了橡胶O形圈在安装和使用中的接触变形、接触宽度和密封界面上的接触应力分布规律，从而为进一步可靠设计、优化橡胶O形圈提供了理论依据。     

超高液压下O形橡胶密封圈的有限元分析

利用ABAQUS软件对O形橡胶密封圈在超高液压下的应力和接触压力进行了有限元分析,探讨了不同压力下O形橡胶密封圈的VonMises应力和接触压力的变化规律,分析了压缩率及密封间隙对最大VonMises应力与最大接触压力的影响。结果表明在超高液压下,O形圈VonMises应力主要集中在液压缸与活塞杆的密封间隙区域,且最大VonMises应力随着密封间隙的增加而显著上升;压缩率对初始应力和接触应力影响较大,适当提高压缩率能够提供密封的可靠性,O形圈最大接触应力随着油压的增加呈近似线性变化。     

O形圈的有限元分析

该文首先利用商业有限元软件ABAQUS建立了O形密封圈的有限元模型,考虑到大变形和橡胶材料的非线性,分析了O形密封圈在初始压缩和流体压力状况下的剪应力、接触压力的分布.然后计算了活塞运动状态下密封圈与气缸壁之间的摩擦力,并分析了速度对摩擦力大小的影响.最后分析了流体压力、压缩率以及密封圈库仑摩擦系数的大小对最大接触压力和剪应力的影响.     

O形橡胶密封圈密封性能的有限元分析

利用ANSYS建立了液压系统中液压缸用O形橡胶密封圈的二维轴对称模型,分析计算了O形密封圈缸筒和轴套的间隙、密封轴套槽口倒角半径、O形密封圈的截面尺寸、橡胶材料参数、初始压缩率对密封面最大接触压力和剪切应力的影响。结果表明:O形密封圈缸筒和轴套的间隙对剪切应力的影响很大;轴套沟槽宽度、O形密封圈的截面尺寸和橡胶材料参数对密封面最大接触压力的影响很大;初始压缩率对密封面最大接触压力和剪切应力的影响都很大;对于本文分析的结构,在其它条件不变的情况下密封轴套槽口倒角半径对密封面最大接触压力和剪切应力的影响都不大;分析结果验证了长期使用的经验设计。     

基于ANSYS的O形密封圈可靠性分析及软件开发

考虑随机不确定性因素的影响,对某型号O形密封圈进行可靠性分析。通过ANSYS参数化语言APDL建立O形密封圈参数化模型,根据应力-强度干涉模型及密封圈的工作特点建立其可靠性模型。假设密封圈的几何参数、载荷及屈曲强度为服从正态分布的随机变量,运用ANSYS的概率设计系统PDS对密封圈进行可靠性计算。利用VB6. 0将ANSYS的APDL代码进行了封装,编写了O形密封圈的可靠性分析软件。该项研究可为液压元件的可靠性计算与专用软件开发提供借鉴意义。     

O形密封圈引起的摩擦力的计算

本文以安装在作往复运动活塞上的O形密封圈为对象,通过数学、力学的推导,计算出O形密封圈所引起的摩擦力。     

Influence analysis of secondary O-ring seals in dynamic behavior of spiral groove gas face seals

The current research on secondary O-ring seals used in mechanical seals has begun to focus on their dynamic properties. However, detailed analysis of the dynamic properties of O-ring seals in spiral groove gas face seals is lacking. In particular a transient study and a difference analysis of steady-state and transient performance are imperative. In this paper, a case study is performed to gauge the effect of secondary O-ring seals on the dynamic behavior (steady-state performance and transient performance) of face seals. A numerical finite element method (FEM) model is developed for the dynamic analysis of spiral groove gas face seals with a flexibly mounted stator in the axial and angular modes. The rotor tilt angle, static stator tilt angle and O-ring damping are selected to investigate the effect of O-ring seals on face seals during stable running operation. The results show that the angular factor can be ignored to save time in the simulation under small damping or undamped conditions. However, large O-ring damping has an enormous effect on the angular phase difference of mated rings, affecting the steady-state performance of face seals and largely increasing the possibility of face contact that reduces the service life of face seals. A pressure drop fluctuation is carried out to analyze the effect of O-ring seals on the transient performance of face seals. The results show that face seals could remain stable without support stiffness and O-ring damping during normal stable operation but may enter a large-leakage state when confronting instantaneous fluctuations. The oscillation-amplitude shortening effect of O-ring damping on the axial mode is much greater than that on the angular modes and O-ring damping prefers to cater for axial motion at the cost of angular motion. This research proposes a detailed dynamic-property study of O-ring seals in spiral groove gas face seals, to assist in the design of face seals.     

激光加工的多孔端面机械密封的性能数值分析

建立激光加工多孔端面机械密封的分析模型,采用有限差分法求解雷诺方程,得到不同操作条件和微孔结构参数 下密封端面间的流体压力分布,进而可以计算端面间的密封开启力和液膜刚度。通过分析端面结构参数对密封开启力 和液膜刚度的影响规律,可得到端面结构的优化参数。分析结果表明,微孔密封面可产生明显的动压效应。     

High pressure hermetic compression seals for embedding elastomeric membrane microvalves in polymer microfluidic devices

The application of elastomeric membrane microvalves with polymeric microfluidic devices is currently impeded by bonding methods which limit operating pressures. A novel compression sealing approach is presented for embedding elastomeric membranes between polymeric microchannel laminae through the use of sealing bosses. Sealing bosses are used effectively to concentrate clamping forces producing compression seals with higher operating pressures. The technique is capable of integrating elastomeric membrane microvalves within a wider variety of materials. Further, compression seals allow devices to be disassembled allowing for cleaning and analysis. Finite element methods are used to investigate the effects of sealing boss size and location on valve deformation as a function of clamping pressure. Experimental results are in good agreement with the model and show that the device can be configured to withstand operating pressure beyond 689 kPa.     

Modelling of cross-ply piezoelectric composite laminates in cylindrical bending with interfacial shear slip

An approximate theory for cross-ply piezoelectric composite laminates in cylindrical bending with interfacial shear slip is developed. This theory uses only 4 displacement and potential variables, the number of which is independent of the number of layers involved. The displacement and electric potential fields are depicted by the displacement and electric potential distribution functions through thickness, respectively. The two functions are formulated according to particular solutions to the three-dimensional elasticity equilibrium equations and electrostatics charge equation. In this shear slip modelling interfacial opening is neglected. The interfacial bonding conditions are characterised by a linear slip law and an electrically permeable assumption. A corresponding finite element is also developed to deal with piezoelectric laminates with local shear slip. The accuracy and effectiveness of the present theory are demonstrated in numerical examples.     

Hydrodynamic lubrication of rubber seals for reciprocating motion; leakage of seals with an O-ring

The solution of design and operational problems in sealing technology requires definition of the lubrication parameters underneath the sealing ring. Knowledge of the film thickness enables one to define the out-leakage, the most important sealing parameter. A review of theoretical and experimental equations defining the lubricating film thickness is presented. An original method of measuring the film thickness is described, and an attempt is made to explain the differences that exist between the theoretical and experimental equations.     

激光加工多孔端面机械密封的参数研究

建立了激光加工多孔端面机械密封的流体动力学分析模型。根据基本假设,一个孔栏上的液膜压力分布可表征整个密封面上的液膜压力。将参数进行无量纲化,采用有限差分法对激光加工多孔端面机械密封进行了参数研究,并利用MATLAB计算机软件得到了无量纲液膜压力的三雏分布规律。由计算分析可知,液膜平均压力随着液体粘度和转速的增加、液膜厚度的减小而增大;随着流体压力的增大,微孔产生的动压效应减弱。另外,微孔密度和微孔深径比的对液膜平均压力有很大影响,对其进行优化,可使平均液膜压力达到最大。     

基于ABAQUS的二维金属切削有限元分析

运用大型通用有限元分析软件ABAQUS对金属切削加工过程进行非线性弹塑性有限元分析,讨论了切削模拟过程中切削力、应力场、应变的变化情况,验证了通过剪切失效和单元删除模型实现切屑分离符合切削理论。     

Inter-asperity cavitation and global cavitation in seals: : an average flow analysis

A universal, average Reynolds equation was previously developed to model the combined effects of inter-asperity cavitation and global cavitation in lubricating films between rough surfaces. In this study, the universal, average Reynolds equation is applied to two types of rotating shaft seals: lip seals and mechanical face seals. Inter-asperity cavitation is shown to affect the sealing mechanism of lip seals and to influence the behavior of new, worn, and wavy mechanical face seals.     

带阻尼套筒的篦齿封严结构模态计算方法研究

这里采用波传播技术对带阻尼套筒的篦齿封严结构进行了振动特性的计算分析,通过建立接触面刚度矩阵来模拟阻尼套筒对篦齿封严结构固有振动特性的影响,对各参数进行无量纲处理,使所得结论具有通用性效果。     

有限元分析法在工程密封件设计上的应用

基于橡胶应力应变的关系,可以假设橡胶材料具有各种形式的应变能函数,由橡胶的基础实验数据作参数拟和,选取合适的应变能函数。利用大型有限元分析软件ABAQUS,考察了3种类型的橡胶圈的大变形引起的几何非线性和接触非线性。通过建立有限元模型,施加边界条件和载荷等步骤,得出橡胶圈的应力场分布情况,说明有限元分析方法可以适用于研究液压缸的密封性能。