The establishment of critical wrinkling judgment line for shear wrinkling instability of thin plate and its influencing factors

Abstract

Wrinkle is a common and unpredictable forming defect in thin-walled components forming process. The complex stress loading paths caused by different forming conditions are the main reasons for the unpredictable wrinkling. It has important theoretical and practical significance to accurately predict wrinkling and instability of thin-walled components under different stress loading paths. In this paper, the shear wrinkling experiment was taken as the research object, and the Buckle-Explicit algorithm in ABAQUS was used to establish the numerical analysis model of shear wrinkling. The accuracy of the simulation algorithm was verified by comparative experiments; Based on the results of numerical analysis, the definition method of critical wrinkling time under shear wrinkling was clarified; By changing the size of test specimens, the influence of height and width on the critical wrinkling stress and strain of shear wrinkling was studied; By changing the shape of the specimen, different stress loading paths were obtained, and a unified wrinkle judgment diagram was established by using the stress–strain data under different stress loading paths; The prediction of that judgment diagram of specimens under different stress loading paths was verified; Taking the upper circular lower square specimens with different thickness as examples, the distribution law of the unified critical wrinkling judgment point was analyzed. It was found that the plate thickness had no obvious effect on the unified wrinkling limit diagram established in this paper.