自紧式V形金属密封特性及悬臂结构影响

Sealing Characteristics and Influence of Aantilever Geometry on Pressure-actuated V-shaped Metal Seal

自紧式V形金属密封在液体火箭发动机中有广泛应用,然而不同使用环境下的结构形式、几何参数、材料选用等变化繁多。基于工况和空间约束设计了一种V形金属密封结构,并基于ABAQUS平台,建立V形金属密封装配-承压-卸载-拆卸全工作过程有限元模型,研究工作全过程的密封特性和可控几何参数影响。结果表明:密封唇高温承压后屈服变形并持续增加属塑性变形,密封悬臂处塑性变形先增加后保持不变,具备良好自紧特性,拆卸分离后密封唇处无明显局部压痕、密封件回弹率为88.4%,可保证密封性能和重复使用性;回弹率随两悬臂间内张角α和悬臂内外侧张角β增加而增加,β对接触压强和回弹率影响大于α;通过几何参数优化,可进一步提高回弹率。

Pressure-actuated V-shaped metal seal has been widely used in liquid rocket engine.However,there are lots of variations of structural style,geometrical parameter and material selection for different service environments.A V-shaped metal seal has been designed based on the working and spatial constraints.Based on ABAQUS code,a FE model for assembling-pressuring-unloading-disassembling through-process of V-shaped metal seal has been developed.The sealing characteristics and influences of the controllable geometrical parameter during working through-process have been studied.The results indicated that the sealing lip yields and the plastic deformation progressively increases after pressure bearing with high temperature,and the plastic deformation on cantilever increases firstly and then is almost unchanged during the working through-process,so the structure of seal has a well self-tightening feature;there is not obvious local indentation on sealing lip after disassembling,and the resilience rate is about 88.4%;thus the seal has well sealing performance and reusable performance;the resilience rate increases with increasing inner angle(α)between two cantilevered legs and angle(β)between inside and outside of cantilevered leg,and the influences ofβon the contact pressure and resilience rate is more than that ofα;so the resilience rate can be further improved by optimizing the geometrical parameters.