钛合金梁式管接头密封性能的结构优化设计

为优化具有椭圆弧凹槽的航空钛合金梁式管接头,基于ABAQUS软件建立了梁式管接头弹塑性接触有限元模型,得到了阴、阳接头两道密封处的接触应力分布与接触带宽。综合考虑梁式管接头宏观几何结构与接触面微观形貌,以S指数为密封性能评价指标,利用Isight软件和多岛遗传算法得到了密封性能最优的阴接头几何构型。对最优结构的有限元数值模拟表明,优化结构的S指数比原型和数据库最大值结构分别提高102.2%和53.1%,其最大接触应力与接触带宽明显增大,优化结构的密封性能显著提高。最优结构的S指数与优化方法的预测值吻合良好,从而验证了优化方法的有效性和结构优化设计的准确性。采用的S指数密封评价准则相比于传统单纯以接触应力或接触带宽评价密封性能的方法更全面考虑了密封结构的宏观与微观特征,为梁式管接头密封结构优化设计提供了可量化的密封性能目标函数。应用Isight软件与多岛遗传算法可提高计算效率与优化精度。

Structural optimization design of sealing performance for titanium alloy beam seal

To optimize titanium alloy beam seal with elliptical arc groove, based on ABAQUS software, the elastic-plastic contact finite element model of the beam seal was established, and the contact stress distribution and contact bandwidth of the two seals between the male and female connectors were obtained. Taking S index as the evaluation criterion of sealing performance, which considers both the macro geometry of the beam seal and micro morphology of the contact surface, the female connector with the best sealing performance is obtained by using ISIGHT software and multi-island genetic algorithm. The simulation demonstrates that its S index is 102.2% higher than that of the prototype, 53.1% higher than the maximum in the database, and its maximum contact pressure and contact bandwidth are remarkably increased, which means that the sealing performance of the optimized geometry is significantly improved. The S index of optimized beam seal is in good agreement with the prediction value of the optimization method, which verifies the effectiveness of the optimization method and the accuracy of the optimized geometry. Compared with the traditional method of evaluating the sealing performance only by contact stress or contact width, the S index comprehensively considers the macro and micro characteristics of the seal and provides a quantifiable sealing performance objective function for the optimization design of the beam seal. The application of ISIGHT software and multi-island genetic algorithm can improve the calculation efficiency and optimization accuracy.