Diffraction of magnetic field in a device of circular rings

Diffraction of Electromagnetic Wave by Circular Disk and Circular Hole

The problem of diffraction of an electromagnetic plane wave by a perfectly conducting circular disk and its complementary problem, diffraction by a circular hole in an infinite conducting plate, are rigorously solved using the method of the Kobayashi potential. The mathematical formulation involved dual integral equation derived from the potential integral and boundary condition on the plane where a disk or hole is located. The weighting function in the potential integral are determined by applying the properties of the Weber-Schafheitlin's discontinuous integral and the solution are obtained …

Distorted Born Diffraction Tomography: limits and applications to inverse the ultrasonic field scattered by an non-circular infinite elastic tube

This study focuses on the application of ultra sonic diffrac tion tomography to noncircular 2D-cylindri - cal ob jects im mersed in an in fi nite fluid. The dis torted Born it er a tive method used to solve the in verse scat ter ing prob lem be longs to the class of al ge braic re con struc tion al go rithms. This method was de vel - oped to in crease the or der of ap pli ca tion of the Born ap prox i ma tion (in the case of weakly-con trasted me dia) to higher or ders. This yields quan ti ta tive in for ma tion about the scat terer, such as the speed of sound and the at ten u a tion. Quan ti …

弹性圆盘在圆形支撑环上的压痕

Indentation of an elastic disk on a circular supporting ring

本文通过实验与理论研究圆形环支撑弹性圆盘的压痕行为，揭示压缩应力通过遍布屈曲或局部d-锥两种途径释放，并给出压痕阈值与纵横比的关系。

Electrostatic potential and electric field in the $z$ axis of a non centered circular charged ring

In introductory level electromagnetism courses the calculation of electrostatic potential and electric field in an arbitrary point is a very common exercise. One of the most viewed cases is the calculation of electrostatic potential and electric field in the symmetry axis of a centered ring and it has been widely studied the potential off the axis of a charged ring centered in the origin coordinate. In this work, we calculated the electrostatic potential and electric field in the $z$ axis of a non centered charged ring using elliptic integrals as an pedagogical example of the application of sp…

旋转梁与弹性圆结构碰摩的稳定性分析

Stability analysis of rotating beams rubbing on an elastic circular structure

本文用Routh-Hurwitz准则分析了由柔性圆环上的旋转梁组成的系统的稳定性。所展示的模型已通过使用能量方法在旋转框架内得到充分发展。考虑的梁具有两个自由度（dofs），弯曲运动以及牵引/压缩运动。将考虑环的面内变形。发散和模式耦合因此在旋转坐标系中被强调，为了简化对所有这些现象的理解，梁的自由度将首先被单独处理，然后一起处理。弹性环上的径向旋转载荷的动力学可以产生发散不稳定性以及后临界模式耦合。此外，梁在环上的弯曲摩擦运动也会导致模式耦合和轨迹转向现象。摩擦的存在似乎使系统不稳定，只要光束的旋转速度大于零。最后，将研究光束与环内表面法线之间的角度对系统稳定性的影响，从而突出频移现象。

The Conducting Ring Viewed as a Wormhole

We compute the exterior Green function for a grounded equi-potential circular ring in two-dimensional electrostatics by treating the system geometrically as a "squashed wormhole" with an image charge located in a novel but obvious position, thereby implementing a method first suggested in 1897 by Sommerfeld. We compare and contrast the strength and location of the image charge in the wormhole picture with that of the conventional point of view where an image charge is located inside the circular ring. While the two viewpoints give mathematically equivalent Green functions, we believe they prov…