GH536燃烧室帽罩粘性介质压力成形贴模性数值分析

Numerical Analysis of Viscous Pressure Forming Mold Fit Performance of GH536 Combustion Chamber Cap

针对航空发动机燃烧室帽罩贴模性难以精确控制等问题,进行了粘性介质压力成形工艺数值分析,根据成形压力与保压时间的不同,建立了7组粘性介质成形有限元模型,探究成形压力和保压时间对壁厚变化及回弹分布的影响。结果显示,在保压时间一定的情况下,成形压力从20 MPa提高到80 MPa时,帽罩成形的壁厚差从2%降低至0.7%,成形压力为80 MPa时回弹量达到最低值,与成形压力20 MPa相比,回弹量降低约47.1%。在成形压力一定的情况下,保压时间为0.10 s时回弹量达到最低值,与保压时间0.06 s相比,回弹量降低约60.8%。在选定参数范围内,提高成形压力可提高帽罩粘性介质成形的贴模性,相比保压时间,成形压力对帽罩缺陷特征的影响更显著,考虑到高减薄率及增厚率带来的破裂、褶皱等风险,最终选择成形压力为80 MPa,保压时间为0.10 s。

Aiming at the problem that it is difficult to precisely control the mold fit performance of the aero-engine combustion chamber cap,the numerical analysis of the viscous pressure forming is carried out.According to the difference of forming pressure and holding time,7 groups of finite element models of viscous pressure forming are established to explore the influence of forming pressure and holding time on distribution of wall thickness and springback.The results show that under the condition of constant pressure holding time,the wall thickness difference of cap viscous pressure forming decreases from 2%to 0.7%as the increase of forming pressure from 20 MPa to 80 MPa.When the forming pressure is 80 MPa,the springback reaches the lowest value,which is about 47.1%lower than that of 20 MPa.In addition,under the condition of constant forming pressure,the springback reaches the lowest value when the holding time is 0.10 s.Compared with the holding time of 0.06 s,the springback value decreases by about 60.8%.Within the selected parameters range,increasing the forming pressure can improve the mold fit performance of the cap viscous pressure forming.Compared with the holding time,the forming pressure has a more significant effect on the defect characteristics of the cap.Considering the risks of cracks and wrinkles caused by high thinning rate and thickening rate,the final selection of forming pressure is 80 MPa,and the holding time is 0.10 s.