带止裂筋整体翼梁结构的破损安全分析与试验

为了研究带止裂筋整体翼梁结构的裂纹扩展特性,采用ANSYS有限元软件对裂纹尖端应力强度因子进行数值计算,对缩比试验件进行疲劳裂纹扩展试验,当裂纹扩展到止裂筋前时进行剩余强度试验。结果表明:在梁缘条和蒙皮断裂情况下,止裂筋能够降低梁腹板上的应力强度因子幅值,对裂纹扩展起到拟制作用,其能够承担较大的静载荷从而实现破损安全设计,但是用止裂筋阻止疲劳裂纹扩展的效果并不显著;与梁弯曲产生的正应力相比,腹板上的剪应力不足以驱动Ⅱ型裂纹扩展。

Fail-safe Analysis and Test for Integral Wing Structure with Stopping-crack Stringer

The stress intensity factors of the integral wing beam structure with stopping-crack stringer are re- searched by using FEM software ANSYS, and the crack propagating tests are achieved using simulate specimen. Results indicate that the value of the stress intensity factors is of a sharp decline because the normal stress in the beam is shared by the stringer, and it has the ability to share high static load so as to achieve fail-safe design be fore the crack extend to the stringer, nevertheless it is hard to stop the crack propagation by stringer. Beside, the shear stress in beam web cannot serves to propagate mode ]] crack since the ratio of the shear stress to the normal stress is small.