37000字 52页
摘 要
随着时代的发展和科技的进步，先进的制造技术不断涌现，各领域对微型产品的需求逐渐增加，产品的微型化已成为整个制造业发展的一个趋势。这种趋势无疑会给微零件制造技术提出更高的要求，现如今微成形技术已成为国内外学者竞相研究的对象。本文在分析微冲裁工艺的国内外现状，尤其是激光冲击成形技术研究进展的基础上，结合激光驱动飞片技术，提出了激光驱动飞片间接冲击金属箔板技术应用于微齿轮制造的可能性。基于对激光驱动飞片微冲裁成形机理的分析，开展了激光间接冲击微冲裁工艺数值模拟方面的研究。主要工作如下：
首先，阐述了激光驱动飞片微冲裁工艺的成形机理。包括激光与物质之间的相互作用、激光诱导形成等离子体冲击波机理、激光驱动飞片的影响因素及飞片的结构、激光驱动飞片机理等，这些研究为微齿轮制造过程中工艺参数的合理选择及成形过程的数值模拟奠定了坚实的基础。
然后，概括了微齿轮制造技术的研究现状，随着微齿轮的应用越来越广泛，微齿轮在微机械中的重要性逐渐凸显出来。数值模拟结果的好坏受微齿轮工艺参数的影响很大，所以合理选择微齿轮的工艺参数非常关键。当然，在没有前人研究可以借鉴的情况下，要做到这一点并不容易，工艺参数的合理选择必然是一个循序渐进而且十分漫长的过程。
最后，开始进行激光驱动飞片制造微齿轮的数值模拟。由于微齿轮的轮廓复杂，而在ANSYS软件中建立具有复杂轮廓的模型十分困难，所以本文选择在Pro/E中建立微齿轮的三维模型，再通过拉伸除料获得微齿轮模具。Pro/E中的模型保存为IGES格式后可直接导入ANSYS进行前处理，ANSYS的强大兼容性在此时得以体现。基于ANSYS/LS-DYNA软件平台，本文采用有限网格单元法（FEM方法）对金属箔材进行微冲裁数值模拟。利用FEM方法揭示激光驱动飞片微齿轮冲裁过程中工件的变形情况、冲裁后工件的残余应力分布以及激光脉冲能量对模拟结果的影响。此次数值模拟的成果将给后续微齿轮冲裁实验及生产提供有力的参考。
关键词：激光间接冲击；微冲裁；微齿轮；数值模拟
ABSTRACT
With the development and advancement of technology, advanced manufacturing technologies have been blossoming. The demands of micro-products are increasing in various fields. Hence, miniaturization has become a trend in manufacturing industry. This trend will no doubt set a higher requirements on micro-parts manufacturing technology. Nowadays, micro-forming technology has become the object of research for scholars all over the world. Based on the study of micro punching technology both at home and abroad, especially the technology of laser shock forming technology as well as laser-driven flyer technology, the article studies the possibility of applying laser-driven indirect shocking metal foil technology to the manufacture of micro-gear. Through the analysis of micro- forming theory of laser–driven flyer, the article studies the numerical simulation on micro punching under laser indirect shock. The main ideas are as follows:
Firstly, the essay expounds the forming mechanism of laser-driven flyer’s micro punching technology, which includes the interaction between laser and substances, laser-induced formation of shockwave, factors influencing laser-driven flyer and the structure and mechanism of laser-driven flyer. These studies serve as a solid foundation for choosing reasonable parameters and numerical simulation in the forming process of micro-gear.
Secondly, it summarizes the research status of micro gear manufacturing technology. With a wilder application of micro gears, micro gear plays a more and more important role in micro-mechanical. The quality of numerical simulation results is greatly affected by micro-gear parameters, so that choosing reasonable parameters of micro-gear is critical. Without the help of previous studies, it is not easy to make a progress. Hence, a reasonable choice of process parameters will be a very long and gradual process consumes great effort and large amount of time.
Thirdly, it starts the simulation of laser-driven flyer manufacture of micro gears. As the contours of micro-gears are complex and building a complex contours model in ANSYS is very difficult, the author choose to create three-dimensional model of micro-gear in Pro/E and then get a micro-gear mold through the process of stretching and cutting. A Pro/E model can be saved as an IGES format which can be directly imported to ANSYS to do a pretreatment. ANSYS’s powerful compatibility is reflected under this condition. With the help of ANSYS/LS-DYNA software, the essay uses a finite grid method (FEM method) to simulate the micro punching of metal foil. Through this method, it recovers deformation of laser-driven flyer in the process of micro punching the distribution of remained force after blanking and the impact of laser pulse energy on simulation results. The results of numerical simulations will be useful for further experimental and production of micro-gear punching.
KEY WORDS: laser indirect shocking；micro punching,；micro-gear,；numerical simulation
目 录
任务书..........................................................I
摘 要...........................................................IV
ABSTRACT........................................................V
第一章 ?.
