失稳起皱是铝合金薄壁矩形波导管绕弯成形过程中的主要缺陷之一，严重制约着薄壁矩形管绕弯成形极限的提高。笔者采用有限元数值模拟结合正交回归分析的方法，建立了薄壁矩形管绕弯成形起皱波纹度回归预测模型，并通过实验验证了该模型的可靠性；在此基础上推导出了基于失稳起皱成形极限的解析模型。研究获得了芯头个数、防皱块与管坯间隙及芯模与管坯间隙对起皱极限的影响规律，并获得了铝合金薄壁矩形管绕弯成形起皱极限图。该研究为提高实际生产中薄壁矩形管绕弯成形质量提供了依据和指导。

Wrinkling is one of main forming defects of the rotary-draw bending process for thin-walled rectangular aluminium alloy tube, which severely restricts the improvement of the forming quality and forming limit. Therefore, a regression prediction model of the wrinkling wave height is built based on finite element(FE) simulation combined with orthogonal regression analysis, and its reliability is validated by experiments. Then the analytical model of forming limit without the occurrence of wrinkling is derived. The laws of the core number, the clearance between mandrel and tube and the clearance between wiper die and tube affecting wrinkling limit are obtained, and the wrinkling limit diagram for the rotary-draw process of thin-walled rectangular tube is obtained.This research provides basis and guidance for improving forming quality of the rotary-draw bending process for the rectangular tubes in production.

国家自然科学基金资助项目(50575184；50975235)；华中科技大学材料成形与模具技术国家重点实验室基金(08-3)；西北工业大学基础研究基金资助项目(NPU-FFR-200809)