丝束变角度层合板屈曲性能的参数化研究
Parametric study on buckling property of variable angle tow laminates

通过选择合适的纤维轨迹, 丝束变角度(VAT)层合板相对于直纤维层合板能拥有更好的抗屈曲特性。为研究纤维轨迹特征长度和定向坐标系偏角对VAT层合板屈曲性能的影响, 首先对原始的纤维角度线性变化方法进行改进, 提出了一种纤维角度分段线性变化方法, 拓展了纤维轨迹的设计空间;其次, 采用改进后的纤维轨迹定义方法构建了一系列变刚度层合板;最后, 基于有限元方法, 从内力分布角度对变刚度层合板不同承载情况下的屈曲性能进行研究和探讨。数值结果表明:单向轴压工况下, 采用半边长的特征长度和90°偏角的纤维轨迹, 能使层合板的稳定性最好;双向轴压工况下, 应将特征长度和定向坐标系偏角作为额外的设计变量, 并通过优化获得最优的纤维轨迹。 With suitable fiber path, variable angle tow (VAT) laminate is superior to traditional straight fiber laminate in buckling resistance. The aim of this paper is to trace the influence of fiber path characteristic distance and directional coordinate rotation on buckling property of VAT laminates. The original method for linear vibration of fiber angle was improved, and a method for describing the piecewise linear variation of fiber angle was proposed, which is able to extend the design space of fiber path. A series of VAT laminates were fabricated utilizing the improved method. Based on the finite element method, the buckling properties of VAT laminates under different load cases were traced and discussed from the perspective of the stress resultant distribution. The numerical results show that under the axial compression condition, the fiber path with the characteristic distance being half of the edge length and the coordinate rotation being 90°, makes laminates of the highest stability; under the biaxial compression condition, the characteristic distance and directional coordinate rotation should be treated as extra design variables, and the optimal fiber path should be obtained through optimization. 国家自然科学基金(11402204)