基于ABAQUS的橡胶密封圈应力松弛分析

Stress Relaxation Analysis of Rubber Sealing Ring Based on ABAQUS

橡胶O形密封圈在高温工况下会发生应力松弛并导致密封失效。基于橡胶黏-超弹本构模型,利用有限元软件ABAQUS建立橡胶O形密封圈与沟槽接触的非线性有限元模型,分析O形密封圈在不同压缩率、不同油压、不同温度下的应力松弛情况及应力分布。结果表明:接触界面上的接触应力分布近似呈抛物线;O形密封圈应力在初期先急剧衰减,而后逐渐缓慢降低;压缩率和油压对应力松弛影响不大,但油压太大会降低密封可靠性;温度升高使应力松弛速率明显增大,并使最终应力降低,降低密封的可靠性。

The stress relaxation of rubber O-ring will occur at high temperature and lead to seal failure.Based on the viscoelastic-hyperelastic constitutive model of rubber,the non-linear finite element model of the contact between rubber O-ring and groove was established by using finite element software ABAQUS.The stress relaxation and stress distribution of rubber O-ring at different compression rates,oil pressures and temperatures were analyzed.The results show that the distribution of contact stress on the contact interface is approximately parabolic.The stress of O-ring is decreased sharply at the initial stage,then decreased slowly.Compression ratio and oil pressure have little effect on stress relaxation,but too high oil pressure will reduce the sealing reliability.The increase of temperature will obviously increase the stress relaxation rate and reduce the final stress,thus reducing the sealing reliability.