折线型截面复合材料层合梁弯曲性能预测与分析

Prediction and Analysis of Bending Performance of Laminated Composite Beam with Broken Line Section

基于各向异性复合材料层合板弹性理论,研究空间折线型复合材料层合梁弯曲性能计算方法。首先推导了考虑铺层设计的翼缘板和腹板在局部坐标系下的刚度矩阵和本构关系,然后通过平行移轴原理建立折线型复合材料层合梁的整体抗弯刚度理论计算公式,在此基础上求出结构在竖向荷载作用下的挠度值。有限元与理论值对比表明本文的理论计算公式有较好的精度。此外,还分析了翼缘与腹板水平夹角及纤维纵横向铺层比对层合梁挠度的影响。结果表明:结构的挠度随夹角的增大而减小,且夹角越大理论值与有限元值越接近,而纤维纵横向铺层比的变化对结构挠度影响几乎可以忽略。该弯曲预测方法可用于计算Z型、槽型、工字型等空间折线型截面复合材料层合梁刚度和位移。

Based on the classic elastic theory of anisotropic composite laminated plate,an algorithm of bending behavior of laminated composite beam with broken line section was studied.Firstly the stiffness matrix and constitutive relations of flanges and webs in each local coordinate system were derived,and then theoretical formula of overall stiffness of laminated composite beam was expressed as the sum of the stiffness of flanges and webs by formula of translation of axis.Using the overall bending stiffness,the deformation of the structure under vertical loads could be obtained.The theoretically predicted results of deformation agree well with those obtained from finite element method.In addition,the influences of horizontal angle between flanges to webs and the changes of fiber longitudinal-horizontal proportion on the deflection were discussed.It is show that the deformation decreased with the increase of horizontal angle.It also indicates that the changes of fiber longitudinal-horizontal proportion have little influences on the deflection.The proposed method is also adapted to calculate the bending stiffness of laminated composite beam with Z shape,groove shape or H shape cross section.