A Study on the Structural Design and Analysis Method of Electromagnetic Intelligent Materials

本研究的最终目标是建立包括应力、应变、磁化、极化在内的本构方程的一般理论，并建立电磁智能材料的力学、电磁结构设计/分析方法。本项目第一年提出了3场配方，即混合配方，以提高高渗透率材料的电磁分析精度。这一年，对该公式进行了详细的研究，发现该公式可以统一地处理静磁问题和涡流问题。研究结果发表在3篇论文中。对于结构变形的耦合问题，开发了可处理静磁场下屈曲问题的有限元计算程序。在我们的理论中，得到了磁刚度的一般表达式，并可以估计任意位形结构的临界磁通。该程序采用了三场计算公式，计算悬臂梁的屈曲问题与实验结果吻合较好。圆柱体的屈曲分析正在进行中，结果将在1997年5月在德国举行的非线性电磁系统国际研讨会上以题为“受电磁力作用的固体大变形理论及其在磁弹性问题中的应用”的论文中发表。

The final goal of this research was to develop a general theory of constitutive equations which include stress, strain, magnetization, polarization and establish a mechanical, electromagnetic structural design/analysis method of electromagnetic intelligent materials.In the first year of this project, the 3-field formulation, a mixed formulation, was proposed to improve the accuracy of the elctromagnetic analysis of materials with higher permebility. In this year, the formulation was investigated in detail and it was found that the formulation can treat magnetostaic problems and eddy current problems in a unified way. The results were and being published in 3 papers.As for the coupling problems which structural deformation, an FEM computer program which can deal with buckling problems under a magnetostatic field was developed. In our theory, a general expression of magnetic stiffness is obtained and a critical magnetic flux of a structure with an arbitrary configuration can be estimated. The 3-field formulation was incorporated in this program and a good agreement with experiments was obtained in a buckling problem of a cantilevered beam. Buckling analysis of a cylinder is in progress and the results will be presented asa paper entitled, 'A large deformation theory of solids subjected to electromagnetic forces and its applications to magnetoelastic problems, ' at the International Symposium on Non-Linear Electromagnetic Systems which will be held in Germany in May 1997.