The governing differential equations of thin-walled laminated composite curved beams are derived from the principle of virtual displacement. Curvature effect is fully considered, and various displacement components of curved beams are coupled. Buckling behaviors of both the laminated composite I-section vertically (with horizontal web) and horizontally (with vertical web) curved beams are studied. The characteristic displacement function for pinned-pinned curved beams is used to describe both the in-plane buckling and out-of-plane (spatial) buckling behaviors. Closed form solution for buckling analysis of I-section curved beams under compression and bending moment is obtained. Accuracy of the present closed-form solution is verified by comparing with available solutions in the literature and the numerical results of the finite element method using ABAQUS. Then, a practical application of the closed-form solution for I-section composite laminated curved beams is demonstrated, considering the placement of I-section profile, geometry of section, layup in flanges and web, and central angle. Finally, a parametric study is conducted to evaluate the effect of central angle, arc length, radius of curvature, and fiber angle of laminates on buckling behavior of I-section curved beams with either horizontal or vertical web.

薄壁层合组合弯梁的控制微分方程是根据虚拟位移原理导出的。充分考虑了曲率效应，并耦合了弯曲梁的各种位移分量。研究了层状复合材料I型截面的垂直（水平腹板）和水平（垂直腹板）弯曲梁的屈曲行为。销钉固定弯曲梁的特征位移函数用于描述面内屈曲和面外（空间）屈曲行为。得到了在压缩弯矩作用下工字形弯曲梁屈曲的闭合解。通过与文献中可用的解决方案以及使用ABAQUS的有限元方法的数值结果进行比较，验证了当前封闭形式解决方案的准确性。然后，考虑了I型截面轮廓的放置，截面的几何形状，法兰和腹板的叠置以及圆心角，展示了I型截面复合层合弯曲梁封闭形式解决方案的实际应用。最后，进行了参数研究，以评估层压板的中心角，弧长，曲率半径和纤维角度对水平或垂直腹板I形弯曲梁的屈曲行为的影响。法兰和腹板的叠层以及中心角。最后，进行了参数研究，以评估层压板的中心角，弧长，曲率半径和纤维角度对水平或垂直腹板I形弯曲梁的屈曲行为的影响。法兰和腹板的叠层以及中心角。最后，进行了参数研究，以评估层压板的中心角，弧长，曲率半径和纤维角度对水平或垂直腹板I形弯曲梁的屈曲行为的影响。