双层插值边界面法研究进展

CAD/CAE一体化以及CAE分析的自动化是CAE软件发展的必然趋势,一直以来也是众多软件开发商以及算法研究人员不断追寻的目标.尽管国际市场已经在该领域投入相当多的人力以及物力成本,却未能在关键技术方面给出彻底的解决方案.实现CAD/CAE一体化以及CAE分析自动化的关键在于完整实体分析与网格的全自动划分.以往,基于连续网格(结构化网格和非结构化网格)的数值算法,要做到网格的全自动划分,至少要求CAD模型“干净”,这往往需要对CAD模型进行几何修复,而几何修复又是一个甚至比网格划分更困难且更难以自动化的课题.而双层插值边界面法以及非连续网格的出现,使得CAD/CAE一体化以及CAE分析的自动化成为可能.非连续网格能够有效地实现自动化的CAE分析;双层插值边界面法为非连续网格的应用以及CAD/CAE一体化的实现提供了理论支持.对于边界积分方程中的奇异以及近奇异积分,提出了球面细分法来提升数值积分的准确性以及稳定性.几何映射交叉近似算法和几何交叉近似算法,能够有效地降低稠密矩阵的存储量近似远场矩阵,满足大规模计算需要.基于以上理论的“5aCAE仿真软件”能够直接在原CAD模型上,采用非连续...     

Fabrication of two- and three-dimensional periodic submicron structures by holographic lithography with a 635~nm laserand matched photopolymer

2D and 3D submicron periodic structures are first fabricated by red-induced photopolymerization using a common 635 nm semiconductor laser and specially developed red-sensitive polymer material. The principle of this new photo-polymer material fabrication is explained and the absorption spectra of the material are measured. This fabrication technique allows a deeper penetration into volume and larger interference irradiation area which is more than 1 cm². The optical design, theoretical calculations and experimental results including diffraction patterns verifying the formation of periodic structures are presented. Compared with other fabrication technologies using high-power lasers, this approach has greatly reduced the demand for laser apparatus. Therefore, it is much more accessible to most laboratories and potentially usable in holographic fabrication of photonic crystals and devices in micro electro-mechanical systems (MEMS).