Scientific progress in thin plate analysis: Research on visual recognition method of wrinkling instability

This paper presents a visualization identification technology for wrinkling instability regions of thin plates based on a unified critical wrinkling limit curve, aiming to improve the accuracy and efficiency of wrinkling prediction during sheet metal forming processes. Through theoretical analysis, numerical simulation, and experimental validation, an efficient data processing script was developed to extract stress and strain data from all elements and integration layers in numerical simulation results. The model shape was then reconstructed using MATLAB. Based on this, a systematic coloring rule for wrinkling regions was established in combination with the unified critical wrinkling limit curve, allowing for the intuitive display of wrinkling regions and the morphological characteristics of wrinkle concavity and convexity in the formed sheet metal using different colors. It was found that selecting integration layers close to the neutral layer of the principal stress 2 direction (such as the 4th and 8th layers) for visualization processing can accurately identify wrinkling regions and distinguish between wrinkle peaks, valleys, and slopes, showing high consistency with experimental results. This technology overcomes the shortcomings of traditional commercial finite element software in predicting wrinkling and provides a new method and approach for the efficient and accurate prediction of sheet metal wrinkling problems in engineering practice.