新型电磁成形线圈的仿真分析开题报告
2020-02-20 10:01:38
1. 研究目的与意义(文献综述)
multi-materialdesigns for complex lightweight applications become more and more important inthe context of reducing fossil fuel consumption and subsequent exhaustemissions. electromagnetic forming (emf) can be used to plastically deform lessductile materials (e.g. mg and al compared to steel), reduce spring back, and/orcreate a solid-state weld between dissimilar materials. thus, there are variousniche applications in the automotive, aerospace, and biomedical industries forthis technology.
electromagneticforming theory involves multidisciplinary content such as electricity, electromagnetism, and electrodynamics. due to the complexity of electricity, electromagnetism,electrodynamics and the imperfection of plasticity itself, especially theinteraction between the discharge process and the high-speed deformationprocess of the blank during electromagnetic forming, the theoretical study ofelectromagnetic forming is very complicated and difficult. at present, thereare still many problems in the field of electromagnetic forming that need to befurther studied and solved.
in1958, the united states general electric company exhibited the world's first electromagneticforming machine at the second international peace atomic energy conference ingeneva. in 1962, brower and harrey of the united states inventedelectromagnetic forming machines for industrial production. since then,electromagnetic forming has attracted extensive attention and high attentionfrom various industrial countries. the research on electromagnetic formingtechnology has achieved many application results, among which the united statesand the former soviet union are in a leading position in this field. in theearly 1970s, the former soviet union experts studied the influence of blankdeformation on the discharge loop parameters of the machining coil and blanksystem during the discharge process, and pointed out that the rlc circuit can onlybe approximated when it is small deformation; in 1979, the magnetic fielddistribution of the flat coil was studied, and the unevenness of the distribution(the weak center and the strongest 1/2 radius of the coil) was the main reasonfor the insufficient stamping at the center of the blank. in the mid-1960s,electromagnetic forming machines with energy storage of 50kj, 200kj and 400kjappeared. more than 400 electromagnetic forming machines were used in variousproduction lines in the mid-1970s. in the mid-1980s, electromagnetic formingwas widely used in the united states, the former soviet union, japan and othercountries. in 1994, makoto marata studied the method of electromagnetic bulgingof tube material by direct contact of electrodes. through the experimentalanalysis, the influence of working conditions on current and tube deformationwas studied. the elastoplastic analysis of its bulging process was carried outby finite element method.
2. 研究的基本内容与方案
this paper adopts the flat electromagnetic forming asthe research model to analyze the physical fields like electromagnetic field inthe electromagnetic forming process. then the circuit model of the electromagneticforming experiment platform is constructed. and for the electromagnetic field,electromagnetic process between the forming coil and the workpiece is analyzed.finally, by using comsol multiphysics finite element software, the2d-axisymmetric finite elements model of electromagnetic forming is built tonumerically simulate electromagnetic forming process. analyze the electromagnetic forming working circuit ofthe new coil and the electromagnetic field distribution of the new coil,compare the new coil with the traditional coil, and clarify the advantages ofthe new coil compared with the traditional coil.
electromagnetic forming is a relatively new manufacturingtechnology having significant advantages over conventional forming processes. theprocess is a high velocity forming process where the force deforming the workpieceis electromagnetic force. a current pulse generated by discharging a capacitorbank is used to create a high magnetic field around a coil. this field induceseddy currents in the work piece. the two currents create forces of magnetic repulsionleading to the deformation of the workpiece.
2.1设计的基本内容和目标
3. 研究计划与安排
第1-2周,进一步查阅和阅读文献,了解电磁成形目前存在的问题与技术难点,理解本设计领域复杂工程问题解决方案的设计,对综述进行修改,总结电磁成形各类线圈的优缺点。
第3-4周,熟悉电磁成形的基本原理,设计线圈结构,熟悉有限元数值分析法。
4. 参考文献(12篇以上)
[1]《高能成形》编写组.高能成形[m].北京:国防工业出版社.1969
[2]高能率成形技术[m].国防工业出版社,李春峰编著, 2001
[3]王立峰.强脉冲磁场力作用下板坯自由胀形过程数值模拟的初步研究[d].武汉理工大学;武汉汽车工 业大学,1997.