铺层复合材料风扇叶片榫头元件级静强度试验方法

Test Method for Static Strength of Laminated Composite Fan Blade Dovetail in Element Level

关键词:  风扇叶片  复合材料  榫头  试验方法  静强度测试

Key words:  Fan blade  Composite material  Dovetail  Testing method  Static strength analysis

摘要:

复合材料风扇叶片需要经过积木式多层级验证才能投入使用，元件级试验是其中重要一环。针对铺层复合材料风扇叶片榫头强度问题，研究了榫头元件级静强度试验方法。搭建了榫头元件级静强度试验平台，完成了榫头元件级试样件及其夹具的设计及制造，提出了数据采集、试验流程和试验结果数据分析方法。试验结果表明：榫头元件试样件的失效模式为层间分离；层间正应力是造成铺层分离的主要原因，而层间剪切应力促进了分层裂纹的扩展；层间应力的有限元分析结果验证了试验结论，榫头层间分离发生位置与有限元预测结果吻合较好，证实了有限元模型的有效性。

Abstract:

Building-block approach is considered essential to the certification of composite fan blade before it comes into service， and element-level testing is an important part of it. Considering on the strength problem of laminated composite fan blade dovetail， the element-level dovetail static strength test method was studied. A static strength test platform was built， the design and manufacture of the dovetail element-level specimen and its fixture were completed， the data collection， test process and result analysis method were presented. The results show that the failure mode of the dovetail specimen is interlaminar delamination. The interlaminar normal stress is the main factor for the interlaminar delamination， and the interlaminar shear stress promotes the propagation of delamination cracks. The finite element analysis results of the interlaminar stress verify the experimental conclusions， and the locations of delamination in the test are in good agreement with the finite element prediction results， which confirms the validity of the finite element model.