薄壁管无模内高压成形塑性皱曲的理论分析

基于J M Alexander提出的轴向载荷作用下薄壁管轴对称坍塌机构化模型,针对薄壁管无模内高压成形端部塑性皱曲的局部性特征,提出了一种“皱曲区-膨胀区-皱曲区”的管坯区划模型。通过将基于塑性失稳系数的薄壳塑性稳定性理论与能量准则相结合,在系统势能极小条件下,建立起薄壁管无模内高压成形端部塑性皱曲临界载荷的理论计算方法。

Theoretical Analysis of Plastic Wrinkling in Dieless Thin-walled Tube Internal High Pressure Forming

Based on the axisymmetric collapse mechanism model, proposed by J. M. Alexander for the thin-walled tube under axial compression, this paper introduces a zoning model to analyze the end plastic wrinkling characteristic of the dieless thin-walled tube internal high pressure forming. According to the thin shell plastic stability theory, based on the plastic instability coefficients and energy rule,the theoretical for calculating critical loads of plastic wrinkling on the ends of the hydroformed tube is established under the condition of system potential energy minimization.