Postbuckling behavior of stiffened laminated composite plates is investigated using a simplified spline finite strip method. The base plate and stiffeners are formulated by the first-order shear deformation plate theory and the Timoshenko beam theory, respectively. According to the compatibility condition between the base plate and stiffener, the beam displacements are expressed by the fundamental middle surface displacement component functions of the base plate. The beam-plate assembly is then discretized exclusively by the base plate strips. The longitudinal spline interpolation coefficients of the strip are transformed into actual freedoms of each nodal line, so that the stiffness contribution of transverse stiffeners can be easily incorporated into the strips. The nonlinear governing equation is solved using the Newton–Raphson method. The present beam-plate model is applicable to both global and local plate postbuckling analyses of stiffened plates, and the modification of the spline interpolation makes the spline finite strip method (SFSM) versatile for both the transversely- and orthogonally-stiffened plates. The effectiveness and capability of developed postbuckling analysis are verified by comparisons with numerical finite element results. Parametric studies are conducted to investigate postbuckling behavior of stiffened laminated composite plates. The present simplified SFSM is capable of performing both the critical buckling load prediction and postbuckling analysis of either transversely-stiffened or orthogonally-stiffened laminated composite plates.

使用简化的样条有限条法研究了加筋层压复合板的后屈曲行为。底板和加劲肋分别由一阶剪切变形板理论和铁木辛哥梁理论公式化。根据底板与加劲肋的相容性条件，梁位移由底板的基本中间面位移分量函数表示。梁板组件然后专门由基板条带离散化。条带的纵向样条插值系数转化为各节点线的实际自由度，从而可以很容易地将横向加劲肋的刚度贡献纳入到条带中。非线性控制方程使用 Newton-Raphson 方法求解。目前的梁板模型适用于加筋板的整体和局部板后屈曲分析，并且样条插值的修改使样条有限条法 (SFSM) 对横向和正交加筋板通用。通过与数值有限元结果的比较，验证了所开发的后屈曲分析的有效性和能力。进行参数研究以研究加筋层压复合板的后屈曲行为。目前的简化 SFSM 能够对横向加筋或正交加筋的层压复合板进行临界屈曲载荷预测和屈曲后分析。样条插值的修改使样条有限条法 (SFSM) 对横向和正交加筋板通用。通过与数值有限元结果的比较，验证了所开发的后屈曲分析的有效性和能力。进行参数研究以研究加筋层压复合板的后屈曲行为。目前的简化 SFSM 能够对横向加筋或正交加筋的层压复合板进行临界屈曲载荷预测和屈曲后分析。样条插值的修改使样条有限条法 (SFSM) 对横向和正交加筋板通用。通过与数值有限元结果的比较，验证了所开发的后屈曲分析的有效性和能力。进行参数研究以研究加筋层压复合板的后屈曲行为。目前的简化 SFSM 能够对横向加筋或正交加筋的层压复合板进行临界屈曲载荷预测和屈曲后分析。通过与数值有限元结果的比较，验证了所开发的后屈曲分析的有效性和能力。进行参数研究以研究加筋层压复合板的后屈曲行为。目前的简化 SFSM 能够对横向加筋或正交加筋的层压复合板进行临界屈曲载荷预测和屈曲后分析。通过与数值有限元结果的比较，验证了所开发的后屈曲分析的有效性和能力。进行参数研究以研究加筋层压复合板的后屈曲行为。目前的简化 SFSM 能够对横向加筋或正交加筋的层压复合板进行临界屈曲载荷预测和屈曲后分析。