吸引式板件电磁成形电磁力时空分布规律及材料成形性能研究

Electromagnetic forming (EMF) technology based on an attractive force has an important research value and a vast application prospect in car dent repair. However, in the existing EMF technical system, most research efforts focus on the development of EMF with repulsive forces, while it’s a challenging task to realize the attractive forming process due to the strong coupling between the magnetic field and eddy current. To solve this problem, a discharge system with two sets of power supplies is proposed in this project, to generate a dual-frequency discharge current for adjusting the spatial and temporal distribution characteristics of eddy current in the workpiece. On this basis, taking the Aluminum Alloy dent samples as the research objects, the following numerical and experimental studies are carried out for exploring the regulation law of electromagnetic attractive force under the cooperative work of two sets of power supplies with the aid of a timing control technology, the plastic flow behavior of Aluminum Alloy dent samples and the effects of springback and collision in the forming process and final quality; revealing the relationship among of the the magnetic field distribution, process parameters of electromagnetic forming and the forming quality; developing a new, effective and precise forming method for dent repair of sheet metal components. All these studies are expected to provide theoretical basis and experimental data support to establish the technical system of Aluminum Alloy high-speed electromagnetic attractive forming.

吸引式电磁成形技术在汽车车身凹痕修复领域具有重要的研究价值和广阔的应用前景,但目前的电磁成形系统均为单级放电模式，其磁场与涡流之间具有强耦合作用使得工件上产生的电磁力为排斥力，无法实现吸引式成形。为此，本项目提出采用基于两级脉冲电源系统的双频电流法，来调节磁场和工件中涡流的时空分布特性，进而产生吸引式电磁力。在此基础上，拟以铝合金凹痕样件为研究对象，从数值分析和实验研究两个角度，探寻双脉冲电源协同充放电与时序控制技术下吸引式电磁力场的调控规律、铝合金凹痕样件的塑性流动行为、回弹及碰撞对成形过程和成形质量的影响，揭示电磁力场分布、电磁成形工艺参数以及成形质量间的作用关系，发展一种新型有效的板件凹痕件精确恢复方法，并为建立铝合金高速电磁吸引力成形的技术体系提供理论基础和实验数据支撑。

吸引式电磁成形技术在汽车车身凹痕修复领域具有重要的研究价值和广阔的应用前景,但目前的电磁成形系统均为单级放电模式，其磁场与涡流之间具有强耦合使得工件上产生的电磁力为排斥力，无法实现吸引式成形。为此，本项目提出采用基于两级脉冲电源系统的双频电流法，来调节磁场和工件中涡流的时空分布特性，进而产生吸引式电磁力。项目所提出的磁场和涡流相互解耦的理论模型，充分揭示了吸引式电磁成形过程中电磁力的时空分布特性，对涡流在空间上的竞争关系以及电磁力在时间上的竞争关系进行了充分地阐述，揭示了上述竞争过程对成形效果的影响规律。在理论研究的基础上，项目从工艺角度设计了一系列吸引式电磁成形方案并开展了相关实验研究，充分验证了吸引式电磁成形在板件胀形、小管件胀形和管件扩口等领域的潜在应用价值，为电磁成形在铝合金领域的相关应用获得了大量一手实验数据，为建立吸引式铝合金电磁成形技术体系提供了全面的理论基础和实践支撑。