型材多点柔性成形三维拉弯扭关键技术基础研究

In order to meet the needs of reduce air resistance and transient pressure, the complex three dimensional configuration parts is usually designed for high speed train head structure. To these complex three dimensional structure parts, the forming process is much more complicated than traditional stretch-bending, because of the four deformation mode are involved, such as stretching, cross-section torsion, horizontal bending and vertical bending. The current three dimensional bending method and traditional stretch-bending method cannot meet the one-step forming needs for these complex three dimensional structure parts. In this project, the method based on 6 degrees of freedom controlled module is proposed, and the basic deformation principle of the complex three dimensional profile stretch-bend-twisting is investigated systematically, and the main influence factors and the influence law for cross-section distortion, crinkle and springback is revealed, the forming defects controlling method is found based on the discretization module adjustment. Finally, the key problems on the deformation process controlling method and deformation equipment structure design is solved to make the foundation for the development and practical application.

高速列车头部结构支撑件通常均设计成复杂的三维空间构型，以满足减少空气阻力、降低会车压力波等要求。对于复杂的三维型材结构件，由于涉及拉伸、截面扭转、水平面弯曲以及垂直面内弯曲四种变形方式，成形过程比传统的拉弯成形要复杂得多，现有的传统拉弯方法和三维弯曲成形方法都不能满足复杂截面变曲率型材的三维构件一次成形要求。本项目提出了基于6自由度可控模块单元的三维拉弯扭成形方法，并系统研究型材三维拉弯扭变形的基本规律，揭示型材三维拉弯扭成形过程中截面畸变、起皱及回弹的主要影响因素及影响规律，建立基于离散模块单元调整的成形缺陷控制方法，阐明基于6自由度控制离散模块的三维拉弯扭成形的基本原理，解决成形过程控制及成形装置结构方面的关键理论与技术问题，为该技术的开发与实际应用奠定基础。

本项目提出了基于6自由度可控模块单元的三维拉弯扭成形方法，并开发了基于6自由度控制离散模块的三维拉弯扭成形装置；系统研究了离散模块单元重构型面的曲率对L型截面三维型材成形质量的影响规律，分析了三维拉弯扭成形过程中型材上下表面的位移分布特征；揭示了型材三维拉弯扭成形过程中截面畸变、回弹的主要影响因素及影响规律，分析了水平弯曲角度和垂直弯曲角度对矩形截面型材的三维拉弯扭变形过程中截面畸变的影响规律，研究了基于辊轮式离散模块单元的三维成形机理及其对型材回弹的影响规律，开发了基于BP神经网络模型的回弹补偿算法，建立了基于离散模块单元调整的成形缺陷控制方法，为该技术的开发与实际应用奠定了基础。