应力松弛条件下O形圈的密封性能研究

为了研究O形圈的应力松弛规律及其在应力松弛条件下的密封性能,通过O形圈应力松弛试验,得到其轴向载荷衰减规律,将这些载荷值导入ANSYS中计算出O形圈的接触压力,并利用逾渗理论计算出O形圈密封面的泄漏率。研究结果表明:应力松弛条件下,O形圈上的轴向载荷随时间缓慢下降,初始压力越大轴向载荷衰减得越快,总体来看O形圈上的轴向载荷随时间遵循F_z=Aexp(-t/B)+C的衰减规律;施加的载荷越大O形圈与其接触面各点的接触压力越大,且不同载荷下O形圈与其接触面各点的接触压力均大于介质压力;应力松弛条件下O形圈密封面的泄漏率极小。试验、仿真计算及理论分析均表明,O形圈在应力松弛条件下具有良好的密封性能,证明了O形圈作为静密封的可靠性。

Research on Sealing Performance of O ring under Stress Relaxation

To study the law of stress relaxation for O-ring and its sealing performance under stress relaxation,stress relaxation experiments were carried out on O-rings to obtain the attenuation rule of the axial loads.The value of these loads was taken into ANSYS to calculate the contact pressure of O-ring,and the leakage rate of O-ring sealing face was calculated by percolation theory.Results show that under stress relaxation,the axial load on the O-ring is decreased with time,larger initial force leads to sharper attenuation of axial load,and the axial load follows the attenuation rule of Fz=Aexp(-t/B)+C in general.Larger load applied on the O-ring results in bigger contact pressure between O ring and its contact surface,and the contact pressure is greater than the medium pressure.The leakage rate of O-ring sealing face is extremely small under stress relaxation.Experiment,simulation calculations,and theoretical analysis all show the good sealing performance of O-ring under stress relaxation,demonstrating the reliability of O-ring as static seal