SiC纤维增强整体叶环破裂转速研究

Burst rotation speed of SiC fiber reinforced bling

为研究航空发动机SiC纤维增强钛合金整体叶环的强度,采用有限元法计算了整体叶环子午截面的周向应力分布,分析了其承载模式和理论破裂转速,然后通过高速旋转台试验测定了整体叶环的实际破裂转速。研究结果表明,以复合材料的局部最大周向应力计算的整体叶环的破裂转速与实际测试结果最为接近。叶环残骸断口SEM照片显示,超速旋转过程中首先发生了SiC纤维丝与钛合金基体的界面分脱,随后纤维丝被拉断导致复合材料承载能力下降,最终引起整体叶环的破裂。

To study the strength of SiC fiber reinforced bling for aero-engine,finite element method was ad⁃opted to obtain the circumferential stress distribution of bling meridional plane.Load-carrying mode and theoretical burst speed were analyzed;and the actual burst speed was obtained by the high-speed spin tes⁃ter.It is indicated that the burst speed calculated by the local maximum circumferential stress of composite material is closest to the actual test results.SEM photo of fracture shows that during the overspeed process,SiC fiber thread pull off from the interface of titanium alloy matrix at first,then the fiber was broken,which induced the decreasing of carrying capacity for composite material and the burst of bling.