考虑弹性支撑时蜂窝芯剪切屈曲强度的插值求解方法

Interpolation method for calculating the shear buckling strengths of honeycomb core considering elastic supports

结合最小余能原理和薄板剪切屈曲失稳理论,给出了蜂窝芯等效剪切屈曲强度的理论表达式。将胞壁等效为受弹性支撑的梁,通过对固支和简支条件下的屈曲强度进行插值求解实际胞壁间为弹性支撑时的剪切屈曲强度。然后,利用三点短梁弯曲试验测量常用Nomex蜂窝芯的剪切屈曲强度,并与弹性支撑下的理论解进行对比,试验结果与理论解吻合较好,验证了理论方法的有效性。最后,讨论了剪切屈曲强度的各向异性及蜂窝高度对剪切屈曲强度的影响。结果表明,剪切屈曲强度的各向异性程度与蜂窝高度无关,但随着蜂窝高度的增加,蜂窝芯的纵向和横向剪切屈曲强度均逐渐减少,减小幅度逐渐减缓。

The theoretical form of shear buckling strength of honeycomb core was shown based on the principle of minimum complementary energy and shear buckling theory of thin plate. By regarding the cell wall as a beam with elastic supports, the shear buckling strength of honeycomb core considering elastic supports was got from interpolating the strengths of clamped and simple supports. Then, three point short beam bending tests were performed to obtain shear buckling strength of Nomex honeycomb core. The tests＇ results were compared with theoretical results and agree well with theoretical solutions, which verified our theory. Finally, the anisotropy of shear buckling strength and the influence of honeycomb height on shear buckling strength were investigated. The results show that there is no influence of honeycomb height on the anisotropy of shear buckling strength, while both the longitudinal and transverse shear buckling strengths decrease with the increasing height of honeycomb and the decreasing ratio drops gradually.