运载火箭安全阀用金属波纹管数值模拟及优化研究

Numerical Study and Optimization of a Metal Bellow Used in a Safety Valve for Launch Vehicle

金属波纹管的承压能力直接影响安全阀的功能及可靠性。基于仿真软件Abaqus,对安全阀用金属波纹管在不同外压下的特性开展分析,并对壁厚、外径及材料等因素开展优化研究。结果表明,当外压为0.49MPa时,该波纹管在加载后大部分区域处于材料屈服状态,卸载后波峰仍处于材料屈服状态。增大壁厚、减小外径可提高波纹管承压能力,但均会导致其刚度显著增大。采用GH4169材料可使波纹管在整个工作过程中处于弹性工作区间,且刚度与优化前相当,在承压能力提高的同时,对安全阀动作特性的影响较小。

The pressure bearing capacity of metal bellows directly affects the function and reliability of safety valves.The characteristics under various pressure loads of a metal bellow used in a safety valve are studied based on Abaqus software,and optimizations of the wall thickness,the outer diameter and the material are carried out.The result shows that when the pressure load reaches O.49 MPa,most areas of the metal bellow are already in the material yield state.After unloading,there are still some areas re-maining material yield state at the wave peak.Increasing the wall thickness and reducing the outer diam-eter are both conducive to raising the pressure bearing capacity of the metal bellow,but simultaneously resulting in significant increase of the stiffness.By applying GH4169,the material of the bellow works in its elastic working range during the whole process,and the stiffness is comparable with the previous bellow,which shows an advantage of raising the pressure bearing capacity with minimal additional im-pacts on the operating characteristics of the safety valve.