针对斜向肋箱梁结构中的局部屈曲失稳问题，推导斜坐标系下简支边的弯矩计算公式、纵向面内载荷作用下斜板的屈曲平衡微分方程，将调和微分求积法和边界融入法相结合，给出调和边界融入微分求积法求解简支斜板局部稳定性的具体方法．最后以单向轴压或剪应力作用下的简支斜板为例，研究载荷变化系数、斜板边长比、倾角与屈曲临界载荷之间的关系．结果表明: 单向轴压作用下简支斜板屈曲临界载荷随载荷变化系数的增大而增大，随倾角的增大而减小，随边长比的增大先增大后减小再增大; 剪应力作用下简支斜板屈曲临界载荷随边长比的增大而增大，随倾角的增大先减小后增大．

In order to overcome the local buckling instability of skew plates in box girder,the equations of momentof simply-supported edges in oblique coordinate system and the buckling differential governing equations of skewplates subjected to longitudinal in-plane loads are deduced.Then,by combining the harmonic differential quadraturemethod with the build-in method,a novel method to implement the critical buckling stability of simply-supportedskew plates is proposed. Moreover,by taking the skew plates subjected to uniaxial pressure or shear force as astudy sample,the influences of load-varying coefficient,aspect ratio and skew angle on the critical bulking load areinvestigated. The results show that,when the simply-supported skew plates are subjected to uniaxial pressure,thecritical buckling load increases with the increase of load-varying coefficient and with the decrease of skew angle,however,it undergoes a decrease during its increase with the aspect ratio. Moreover,it is found that,when theskew plates are subjected to shear force,the critical buckling load increases with the aspect ratio,and that it firstdecreases and then increases with the increase of skew angle.