复合材料变截面压杆变形性能研究

Deformation Performance Analysis of Composite Struts With Varying Cross-section

为了对复合材料变截面压杆的变形性能进行理论预测,本文以航天器空间桁架结构中的复合材料变截面压杆作为研究对象,首先,基于经典层合板理论,将复合材料变截面杆的壁板等效为主方向与杆轴线方向一致的正交异性板,此时复合材料变截面杆可近似为正交异性杆;其次,基于弹性变形理论和小变形假设,推导了反映杆轴向变形能力的等效轴压刚度理论公式;最后,利用有限元对等效轴压刚度理论的准确性进行了验证。结果表明,不同中间半径和变截面段长度条件下,理论值和有限元值之间的偏差基本保持在3%以内;不同铺层角条件下,理论值和有限元值之间的偏差基本保持在2%以内。因此,本文的理论能够较准确地预测复合材料变截面压杆的变形。

In order to predict the deformation performance of composite compression struts with variable cross-section,the composite struts used in aerospace truss structure were taken as the research object in this paper.Firstly,wall panel of the composite struts was equivalent to an orthotropic plate,in approximation of an orthotropic strut,the principal direction was consistent with the axial direction of the strut,the composite strut could be approximated as an orthotropic strut.Based on the elastic deformation theory and small deformation assumption,the theoretical formula of equivalent axial compression stiffness was derived.Subsequently,accuracy of the theoretical formula of equivalent axial compression stiffness was verified by finite element method,results showed that:under conditions of different intermediate-radius and variable section-length,the deviation between values of the proposed theory and the finite element is within 3%;under the condition of different ply angles,the deviation between values of the theoretical and the finite element is within 2%.In conclusion,the theory can predict the axial deformation of composite struts with varying cross-section accurately.