宽温域下柔性接头界面损伤及密封可靠性数值研究

Numerical Research on Interfacial Damage and Sealing Reliability of Flexible Joint under Wide Temperature Range

关键词:  柔性接头  界面损伤  内聚力模型  密封可靠性  宽温域

Key words:  Flexible joint  Interfacial damage  Cohesive zone model  Sealing reliability  Wide temperature range

摘要:

界面失效是固体火箭发动机柔性接头的重要问题。为研究宽温域（-55℃～65℃）下柔性接头摆动过程中界面的损伤规律，基于ABAQUS 6.14建立了柔性接头的三维非线性有限元分析模型，并采用内聚力模型作为粘接界面的本构模型，获得了界面的损伤参数。此外，结合界面间的接触应力，提出了一种计算柔性接头密封可靠度的方法。结果表明，宽温域下粘接界面与丁异戊橡胶的力学性能随温度的升高而逐渐下降，说明柔性接头在高温段更容易发生失效；并且确认了柔性接头密封可靠度与界面损伤间成反比关系，宽温域下随着温度升高，柔性接头损伤程度先缓慢增大，-40℃后出现迅速增加，而柔性接头密封可靠度先呈线性下降趋势，20℃后下降趋势放缓，-55℃时柔性接头密封可靠度最大。

Abstract:

Interfacial failure is a serious problem in the solid rocket motor flexible joint. In order to investigate the damage rules of bonding interfaces during flexible joint swinging under wide temperature range (-55℃～65℃), a three-dimensional non-linear finite element analysis was established based on ABAQUS 6.14. Cohesive zone model was adopted as the constitutive model of adhesive to obtain the damage parameters. Additionally, combined with the interfacial contact stress, one computational method to calculate the sealing reliability of flexible joint was proposed. Results illustrate that the mechanical behavior of adhesive and butyl isoprene rubber both decrease gradually with the increase of temperature, indicating that fracture occurs easily at a high temperature. The correspondence relationship between sealing reliability and interfacial damage is confirmed to be inversely related. The damage of flexible joint increases gradually first and grows rapidly above -40℃ with temperature raising, while the sealing reliability presents a linear downward trend first and then slows down above 20℃ with temperature. The sealing reliability reaches maximum at -55℃ under wide temperature range.