锻压技术

中空铝合金型材拉弯成形工艺研究

英文标题：Research on stretch bending of hollow aluminum alloy profile

作者：刘学之张石磊李世涛刘纯国张学广

分类号：TG302

出版年,卷(期):页码：2015,40(5):69-73

摘要：

拉弯成形工艺具有成形精度高、回弹量小、生产效率高的优点，对轨道列车端顶弯梁进行拉弯数值模拟与成形实验。利用数学解析法计算得到了型材拉弯过程中夹钳的运动轨迹，并定义了型材拉弯过程中典型的成形缺陷。利用有限元模拟对比分析不同选材和工艺参数下成形后零件的应力分布、回弹、截面畸变和空间扭转。研究结果表明：选用ENAW-6005-T4材料可以避免型材拉弯过程中的断裂；采用预拉0.5%和补拉1.5%的加载组合时，型材的卸载回弹量最小；采用1.5 MPa的填充压强可以有效地抑制型材外壁的内凹；改善摩擦条件可以减小成形后的空间扭曲。采用优化后的工艺参数进行了实验验证，测量结果和数值分析规律相吻合。

The advantages of stretch bending are excellent forming accuracy, low springback and high production efficiency. Numerical simulation and forming experiment on the end bending beam of rail train were carried out. The trajectory of jaw was obtained by mathematical analysis, and the typical forming defects were defined in stretch bending process of aluminum alloy profile. The stress distribution, springback, cross-section distortion and spatial twist of formed parts were compared and analyzed for different materials and processing parameters by numerical simulation. Numerical simulation results show that ENAW-6005-T4 material can avoid fracture in stretch bending. The loading couple of 0.5% pre-stretch and 1.5% post-stretch can minimize the springback. The filling pressure of 1.5 MPa can restrain the concave of side wall effectively. The spatial twist can be decreased by improving the frictional condition. Experimental validation was conducted with the optimized processing parameters, and measured results show a consistency with numerical analysis.

基金项目：

国家自然科学基金资助项目（51275203）

刘学之（1962-），男，硕士，高级工程师

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