椭圆开孔层合板剪切屈曲仿真预报

为预测不同纤维角度铺层复合材料层合板在中心不同椭圆尺寸开孔下剪切承载能力,利用有限元软件包进行仿真分析.通过改变纤维角度铺层方式和开孔几何参数,得到层合板屈曲载荷变化规律.结果表明(0/90)4和(-45/45)4层合板屈曲特征值随椭圆偏轴角θ=45°对称分布,(-15/75)4和(-30/60)4随θ=45°反对称分布,这主要由于其纤维铺层角度与载荷矢量方向成对称和反对称分布.此外,仿真得到最优椭圆开孔偏轴角度θ为0°,其剪切屈曲特征值随不同椭圆尺寸(c/a=0.1,0.2,0.3)增大而线性减小等规律,这是因为c/a增大扩大了椭圆开孔面积,从而减小了层合板的承载能力.本文最后采用四杆夹具结构进行对角拉伸进行静态加载实验,仿真计算结果和实验屈曲临界值吻合.

Buckling Predication of Laminated Composite with Elliptical Hole under Shearing Loads by Simulation

In order to predict the bearing capacity of composite laminate with different fiber angle-ply and different elliptical cutout geometry parameters,commercial finite element software package was employed.Through varying fiber angle-ply and geometrical parameter of cutout,the law curve is obtained.The results show that buckling loads of(0/90)4 and(-45/45)4 are in symmetry with elliptical rotation angle θ=45°,but the(-15/75)4 and(-30/60)4 are in asymmetry with θ=45°.This is due to the fiber angle-plies are in symmetry or asymmetry with force vector.In addition,the buckling loads with different elliptical scales(c/a=0.1,0.2,0.3) are also calculated numerically,the results show that the optimum elliptical rotation angle θ is zero,and the first shear buckling decreased with the increase of c/a,because it enlarged the area of elliptical cutout that decreased its bearing capacity in respective.Finally,an experiment is carried out with four beams clamp,loaded at cross corners to simulate the shearing load,and the buckling critical load agrees well with numerical results.