To assess the stability and postbuckling behavior of thin composite panels with additional repair lap plates, it is proposed to use relations that consider the unsymmetry of the structure. An analytical solution of the geometrically nonlinear problem is presented for smooth composite panels, whose shape is close to a square, loaded by tangential flows. The initial relations of the problem consider the possible unsymmetry of the structure and include mixed stiffnesses. The boundary conditions in this case correspond to a hinged support. An explicit expression is obtained for the critical stresses of the loss of stability under the action of tangential forces. Relations for the stress-strain state of a square composite panel at its geometrically nonlinear behavior are given. Examples of determination of the critical shear forces are presented, and the expediency of consideration of unsymmetry of the structure in verification calculations of thin composite panels is shown.

为了评估具有附加修复搭接板的薄复合板的稳定性和后屈曲行为，建议使用考虑结构不对称性的关系。对于形状接近正方形、受切向流加载的光滑复合板，提出了几何非线性问题的解析解。问题的初始关系考虑了结构可能的不对称性并包括混合刚度。这种情况下的边界条件对应于铰链支撑。得到了切向力作用下失稳临界应力的明确表达式。给出了方形复合板在其几何非线性行为下的应力应变状态关系。给出了确定临界剪切力的例子，