排气管内高压成形建模关键技术及其工艺参数研究

Key modelling techniques and process parameters for hydroforming process of exhaust pipe

采用有限元模拟和试验相结合是研究排气管内高压成形的重要手段。在解决关键技术的基础上基于ABAQUS有限元建立排气管三维有限元模型,并通过试验结果和模拟结果进行对比验证该模型的可靠性。结果表明:随着内压力、摩擦因数、整形压力、弹性模量以及加工硬化指数的增大,排气管件壁厚减薄增加;随着轴向进给量,以及各向异性指数的不断增加,内高压成形排气管件减薄率逐渐变小;采用正交试验方法最优因素水平组合μ为0.1,L为10 mm,P为100 MPa。

It is an important way to investigate the hydroforming process of exhaust pipe by combining FE simulation and experiment. After solution of several key technical difficulties, a 3D FE simulation model for the hydroforming process of exhaust pipe was established, and it was validated to be credible and efficient. The result shows that with the increase of inner press, friction coefficient, deformation pressure, elastic modulus and hardening exponent, the thinning ratio increase;with the increase of the feeding amount and anisotropic index, the thinning ratio decreases. The optimal process parameters were determined as/μ0.1,L10mm, P100 MPa by orthogonal experimental design.