复合材料长桁终止端设计

Composite stringer runout design

在飞机复合材料加筋壁板结构中,长桁常在机身框、机翼前后梁、结构开口等部位附近终止,长桁终止端头的细节设计对加筋板的承载能力与使用寿命具有重要的影响。由于复合材料的性能和工艺特殊性,长桁端头处的刚度突变,使得长桁与蒙皮之间容易发生脱胶。利用非线性有限元软件ABAQUS中的粘接单元模拟长桁与蒙皮的脱层界面,对复合材料加筋板长桁终止端在拉伸和压缩载荷下的失效机理和失效载荷进行预测,分析长桁端头斜角区不同角度对结构承载能力的影响,为飞机复合材料长桁的细节设计提供参考。

In aircraft composite stiffening panel structure,stringers usually end at the frames,the forward and rear spars and the cutouts. Therefore,the detailed design of stringer run-out has a great impact on the load carrying capacity and service life of composite stiffening panels. Due to the special performance and processing of composite,the stringer and the skin are easy to de-bond with the sudden stiffness change of the stringer end. Simulating delaminated interface with the cohesive elementin nonlinear finite element software ABAQUS,the paper predicts the failure mechanismand failure load of the composite stiffened panels under tension and compression loadand analyzesthe effect of different angles of stringer run-out on the structural load carrying capacityto provide advice to the detailed design of composite stringer.