Study on Electromagnetic Fracture Mechanics of Material Systems for New Electromagnetic Devices

新型电磁器件材料体系电磁断裂力学研究

• 批准号: 08455049
• 负责人: SHINDO Yasuhide
• 金额: $ 5.06万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455049/
• 关键词: Elasticity; Electromagnetic Fracture Mechanics; Integral Transforms; Finite Element Analysis; Material Testing; Electromagnetic Material; Electromagneto-Elastic Interaction; Fracture Toughness; 導電性・磁性材料; 圧電セラミックス; 破壊靱性; 強電磁場; 超伝導応用機器; 電子・電気機械

Design and development of new electromagnetic devices require basic research on electromagnetic fracture mechanics. In this research project, the electromagnetic fracture mechanics of material systems is investigated. From the theoretical considerations and experimental results for electromagnetic material systems, the following can be concluded1) (a) We consider the scattering of time harmonic flexural waves by a through crack in a conducting plate under a uniform magnetic field normal to the crack surface for two special cases, perfect conductivity and quasistatic electromagnetic field, which are of physical interest. The dynamic moment intensity factor versus frequency is computed and the influence of the magnetic field and the angle of incidence on the normalized values is displayed graphically.(b) We discuss the magneto-elastic interactions and singular moments in a soft ferromagnetic plate with a through crack under a uniform magnetic field normal to the plate surface. The static … More and dynamic moment intensity factors are computed and the influence of the magnetic field on the normalized values is displayed graphically.2) We examine the bending of a soft ferromagnetic beam plate in a transverse magnetic field both theoretically and experimentally. The effect of magnetic field on the deflection and strain is shown graphically. A comparison of the deflection and strain is made between theory and experiment, and the agreement is good for the magnetic field considered. We also study the effect of magnetic field on the fracture behavior of a soft ferromagnetic beam plate.3) We consider the cryogenic fracture behavior of structural alloys and weldments for superconductiong fusion magnets in high magnetic fields both analytically and experimentally.4) (a) We consider the static and dynamic problems of cracked piezoelectric materials and composites. Numerical calculations are carried out, and the stress intensity factor, energy release rate and crack growth rate are obtained. We also study the static behavior of the elastic and electric variables in the vicinity of a surface electrode attached to a piezoelectric ceramic.(b) We discuss the scattering of normally incident longitudinal waves by a finite crack in an infinite isotropic dielectric body under a uniform electric field. The dynamic stress intensity factor versus frequency is computed and the influence of the electric field on the normalized values is displayed graphically.5) (a) We perform the bending tests on piezoelectric material systems and examine the piezoelectric effects on the deflection. We also employ the finite element analysis to study the electromechanical behavior of piezoelectric material systems. Numerical results are compared with the experimentally measured response.(b) We carry out the Vickers indentation tests on piezoelectric materials and examine the influence of applied electric field, polarization and load on the fracture toughness. The specimen fracture behavior is also simulated numerically using the finite element technique. Numerical results are provided to illustrate both qualitative and quantitative behavior of the induced electromechanical fields.6) We performe the numerical simulation for analyzing the electromagnetic fracture and deformation of material systems. The predictions obtained from the simulation correlate very well with the experiments. Less

新型电磁器件的设计和开发需要电磁断裂力学的基础研究。本研究课题主要研究材料系统的电磁断裂力学。从电磁材料系统的理论考虑和实验结果可以得出以下结论：1）（a）我们考虑了两种特殊情况下的时谐弯曲波在垂直于裂纹表面的均匀磁场下被导体板中的贯穿裂纹散射，这两种特殊情况是理想导电性和准静态电磁场，这是物理上感兴趣的。计算了动态矩强度因子与频率的关系，并以图形方式显示了磁场和入射角对归一化值的影响。(b)本文讨论了在垂直于板表面的均匀磁场作用下，含贯穿裂纹的软铁磁板中的磁弹性相互作用和奇异矩。静态 ...更多信息 计算了动态力矩强度因子，并以图形方式显示了磁场对归一化值的影响。2）从理论和实验两方面研究了横向磁场中软铁磁梁板的弯曲问题。用图形表示了磁场对挠度和应变的影响。将理论计算结果与实验结果进行了比较，在考虑磁场的情况下，两者吻合较好。本文还研究了磁场对软铁磁梁板断裂行为的影响。3）从理论和实验两方面研究了超导聚变磁体结构合金和焊接件在强磁场中的低温断裂行为。4）（a）研究了含裂纹压电材料和复合材料的静态和动态问题。进行了数值计算，得到了应力强度因子、能量释放率和裂纹扩展速率。我们还研究了压电陶瓷表面电极附近的弹性和电变量的静态行为。(b)本文讨论了均匀电场作用下无限大各向同性介质体中有限裂纹对垂直入射纵波的散射。计算了动态应力强度因子与频率的关系，并以图形方式显示了电场对归一化值的影响。5）（a）对压电材料系统进行了弯曲试验，考察了压电效应对挠度的影响。我们也利用有限元素分析来研究压电材料系统的机电行为。数值结果与实验测量的响应进行了比较。(b)对压电材料进行了维氏压痕试验，研究了外加电场、极化和载荷对压电材料断裂韧性的影响。利用有限元技术对试样的断裂行为进行了数值模拟。数值结果定性和定量地说明了感应机电场的行为。6）对材料系统的电磁断裂和变形进行了数值模拟分析。从模拟中得到的预测与实验相关性很好。少

项目成果

Y.Shindo: "Singular Stress and Electric Fields of a Piezoelectric Ceramic Strip with a Finite Crack under Longitudinal Shear" Acta Mechanica. 120-1/4. 31-45 (1997)

Y.Shindo：“纵向剪切下具有有限裂纹的压电陶瓷条的奇异应力和电场”《力学学报》。

Y.Shindo: "The Scattering of Oblique Flexural Waves of a Cracked Conducting Plate in a Uniform Magnetic Field" Acta Mechanica. 128-1/2. 15-27 (1998)

Y.Shindo：“均匀磁场中裂纹导电板的斜弯曲波的散射”《力学学报》。

Y.Shindo: "Scattering of Oblique Flexural Waves by a Through Crack in a Conducting Mindine Plate in a Uniform Magnetic Field" International Journal of Solids and Structures. (in press).

Y.Shindo：“均匀磁场中传导 Mindine 板中的贯通裂纹引起的斜弯曲波的散射”《国际固体与结构杂志》。

Y.Shindo: "Scattering of Oblique Flexural Waves by a Through Crack in a Conducting Mindlin Plate in a Uniform Magnetic Field" International Journal of Solids and Structures. 35-17. 2183-2203 (1998)

Y.Shindo：“均匀磁场中传导 Mindlin 板中的贯通裂纹引起的斜弯曲波的散射”《国际固体与结构杂志》。

Y.Shindo: "Impact Response of a Finite Crack in an Orthotropic Piezoelectric Ceramic" Acta Mechanica. (in press).

Y.Shindo：“正交各向异性压电陶瓷中有限裂纹的冲击响应”《力学学报》。