Abstract：Local longitudinal buckling is a flatness defect commonly found in the production process of thin and wide strips, and it is a difficult point in buckling research. An accurate analytical solution method is very important for the research of local longitudinal buckling formation mechanism and the improvement of strip flatness quality. In this paper, the local arbitrary longitudinal buckling of the strip is divided into two types: the edge and the interior of the strip. The symplectic elastic method is used to directly derive the critical buckling stress and buckling deflection function when the local longitudinal buckling area is subjected to different boundary constraints and the solution results are compared with the finite element and related literature. The result shows that the symplectic elasticity method has the same calculation accuracy and higher calculation efficiency than the finite element method, and the calculation accuracy is higher than that of the energy method in the reference; The critical buckling stress, buckling area geometry and buckling deflection function are affected by the strip boundary constraint conditions, which verifies the shortcomings of energy method and helps to improve the accuracy of local buckling calculation.
2021, Vol. 42 
