铺层角度对碳纤维/环氧树脂基复合材料板等效刚度的影响

Effect of ply angle on equivalent stiffness of carbon fiber/epoxy composite plates

为了准确计算复合材料等效刚度,指导复合材料设计过程中铺层角度的选择。该文基于经典层合板理论,建立了考虑拉剪耦合效应的三维层合板等效刚度计算方法。基于该方法对碳纤维/环氧树脂基复合材料板等效刚度随铺层角的变化趋势进行了分析,结果显示:随着铺层角θ1的增加,铺层方式为(θ_(1))_(25)/(θ_(2))_(25)的层合板的面内轴向刚度E_(x)、横向刚度E_(y)的变化曲线包含变化率显著不同的两个阶段;法向刚度E_(z)呈正弦变化趋势且当正交铺层时有最大值;面内剪切刚度G_(xy)在θ_(1)=45°且θ_(2)=135°时有最大值;面外剪切刚度G_(xz)和G_(yz)变化曲线关于θ_(2)=90°对称。通过比较层合板与单向板等效刚度发现,选择合适的铺层角度组合能够有效提高结构的法向刚度和面内剪切刚度。

In order to accurately calculate the equivalent stiffness of composite materials and guide the selection of ply angle in the design process of composites.Based on the classic laminate theory,a calculation method for the equivalent stiffness of three-dimensional laminate considering the tensile-shear coupling effect is given.Based on the coupling method,the change trend of the equivalent stiffness of the carbon fiber/epoxy composite plates with the ply angle is analyzed.The results show that:with the increase of ply angle θ_(1),the changes of the axial stiffness E_(x) and the lateral stiffness E_(y) of the laminate with(θ_(1))_(25)/(θ_(2))_(25) show two stages with different change rates.The normal stiffness Ez of the laminate has a sinusoidal trend and reaches the maximum value whenθ1 and θ_(2) are vertical.The in-plane shear stiffness G_(xy) has the maximum value when θ_(1)=45°and θ_(2)=135°.The curves of out-plane shear stiffness G_(xz) and G_(yz) are symmetric with respect to θ_(2)=90°.It is found that the proper ply angle combination can effectively improve the normal stiffness and in-plane shear stiffness of the structure by comparing the equivalent stiffness of laminates and unidirectional slabs.