深海高压舱密封性能评价研究

为了确保基于O形橡胶密封圈的深海高压舱实现可靠密封，避免因经验设计带来的密封失效，提出了通过计算O形橡胶密封圈密封工作时的最大接触应力来判断密封可靠性和安全裕度的评价方法.采用超弹性单元HYPER56建立了O形密封圈的有限元分析模型，计算了高压舱O形密封圈在承受内压时的应力分布.计算结果表明,当O形圈的预压缩量小于1 mm 时，增大O形圈的预压缩量，可以显著提高O形圈的最大接触应力；当O形圈的预压缩量大于1 mm 时，增大O形圈的预压缩量对提高O形圈的最大接触应力贡献不大；当O形圈的预压缩量大于0.6 mm时，O形圈的最大接触应力始终大于密封压力，高压舱能可靠实现60 MPa的密封.对上述结论进行了高压密封实验，实验结果表明，当O形圈的预压缩量为0.8 、1 和1.2 mm时，高压舱能可靠实现60 MPa的密封；通过计算当O形橡胶密封圈密封工作时的最大接触应力，可以对高压密封舱的密封性能做出正确判断.

Sealing performance evaluation of deepsea high pressure cabin

An evaluation method of reliability and safety margin of deepsea high pressure cabin through calculating Oring's maximum working contact pressure was proposed in order to realize reliable sealing and avoid sealing failure caused by experience design.The finite element model of O-ring was built based on the hyperelastic element HYPER56,and the pressure distribution of O-ring was calculated with this model.Calculation shows that when the precompression of O-ring is less than 1 mm,the maximum working contact pressure of O-ring will obviously increase with the increase of precompression;when the precompression of O-ring is greater than 1 mm,the maximum working contact pressure of O-ring will increase slightly with the increase of precompression.When the precompression of O-ring is greater than 0.6 mm,the maximum working contact pressure of O-ring is always greater than the sealing pressure and the cabin can realize reliable sealing at 60 MPa.High pressure experiment showed that when the precompression of O-ring is 0.8,1.0 and 1.2 mm,the cabin can realize reliable sealing at 60 MPa,so the sealing performance evaluation method of deepsea high pressure cabin based on calculation of O-ring's maximum working contact pressure is correct.