A new method has been proposed in this study for the elastic-plastic buckling analysis of stiffened panels under global bending. In this method, a simplified model of the stiffened panels has been built with the application of two theories of plasticity, the incremental theory (IT) and the deformation theory (DT). The effect of transverse shear deformation through the stiffener thickness has been considered using the Mindlin-Reissner plate theory. The governing differential equations have been solved by the differential quadrature (DQ) method and an iteration process has been adopted due to the non-linearity of material properties in the elastic-plastic buckling analysis. Non-linear finite element (FE) modelling of elastic-plastic buckling analysis has been carried out, and the FE results are between those based on DT and IT in general. When the reciprocal of strain hardening exponent $m_t$ increases to 20, the FE results are in a good agreement with DT results. Based on the proposed method and FE simulations, the effect of geometric parameters of stiffened panels (stiffener thickness to height ratio, stiffened panel length to height ratio, width to height ratio, and skin thickness to stiffener thickness ratio) on buckling behaviour in the elastic-plastic region has been investigated and discussed. The proposed method provides an efficient way for parameter optimisation in the structure design of stiffened panels for the aerospace applications.

在这项研究中提出了一种新方法，用于整体弯曲下加劲板的弹塑性屈曲分析。在这种方法中，已使用两种可塑性理论（增量理论（IT）和变形理论（DT））建立了加劲板的简化模型。使用Mindlin-Reissner板理论已经考虑了通过加劲肋厚度产生的横向剪切变形的影响。控制微分方程已通过微分求积法（DQ）求解，并且由于弹塑性屈曲分析中材料属性的非线性而采用了迭代过程。已经进行了弹塑性屈曲分析的非线性有限元（FE）建模，并且该有限元结果通常在基于DT和IT的结果之间。${米}_{Ť}$如果增加到20，则FE结果与DT结果非常吻合。基于所提出的方法和有限元模拟，加筋板的几何参数（加劲板厚度与高度之比，加筋板长度与高度之比，宽度与高度之比以及蒙皮厚度与加劲器厚度之比）对弹性体屈曲行为的影响塑性区已被研究和讨论。所提出的方法为航空航天应用中的加劲板结构设计中的参数优化提供了一种有效的方法。