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1. Curvature Effect on the Properties of Guided Waves in Plates.

Author

Fong, J. and Lowe, M. J. S.

Subjects
WAVES (Physics), CURVATURE, CURVES, MECHANICAL engineering, ENGINEERING, SCIENTIFIC experimentation
Abstract

Inspection techniques using guided waves require an accurate prediction of the propagation properties and the physical behaviour of the waves. Properties of these guided waves can be modelled using dispersion curves, which are calculated numerically. However, any curvature along the propagation direction can change the behaviour of the modes compared to those in the straight waveguide. There are currently few studies of the curvature effect along the propagation direction of any waveguide problem. We have used a 2D circumferential waveguide problem to study the curvature effect, from which the phase velocity and the mode shapes have been examined at various curvatures. The percentage difference in velocity of the low order plate modes, as a function of frequency and curvature, has been calculated numerically. Furthermore the changes in phase velocity have been correlated with the changes in mode shapes that are due to the curvature effect. This paper also presents an experimental study to validate the analytical predictions. The experiment involved a sensitive measurement of the change of velocity as the curvature of a waveguide was increased. Reasonably good agreement was obtained between the experimental measurements and the predictions. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2004
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2. 3D RF-ECT SIMULATIONS OF ISI OF U-BEND SG TUBES IN FBR

Author

Ovidiu Mihalache, Toshihiko Yamaguchi, Masashi Ueda, Kazuyuki Tsukimori, Donald O. Thompson, and Dale E. Chimenti

Subjects
Engineering, Signal processing, Eddy-current sensor, business.industry, Nuclear engineering, Boiler (power generation), Mechanical engineering, Nuclear reactor, Curvature, Finite element method, law.invention, law, Eddy-current testing, Eddy current, business
Abstract

The paper focus on 3‐dimensional finite element simulations of the steam generator inspection using remote field eddy current testing (RF‐ECT) in order to asses the performance of the in‐service inspection in SG tubes. It is evaluated the influences of the SG tubes U‐bend curvature on the eddy current sensor signal by taking into account a 3D model in which also multiple SG tubes are located close to each other, as in the nuclear reactor.

Published
2010

3. Simulative Optimization Of The Rubber Pad Bending Technology For Tubes

Author

M. Nock

Subjects
Tube bending, Engineering, business.industry, Hyperelastic material, Mechanical engineering, Formability, Forming processes, Kinematics, Bending, Structural engineering, Curvature, business, Finite element method
Abstract

Tube bending using an elastomere pad is a flexible bending technique, which belongs to the group of kinematic bending technologies. This new process allows the spatial forming of tubes with variable bending radii and an increased residual formability. The tubes are formed between a rigid roller and a hyperelastic polyurethane pad. In complex bending operations with variable curvatures along the profile axis kinematic shaping shows important advantages regarding set‐up times and tooling costs. The complex co‐action of the process factors necessitates new concepts in process planning. This attempt is solved by a FE modeling. For the optimization of the bending technology regarding tube ovalization and curvature generation different materials have been investigated and evaluated using FE simulation. Simulative parameter studies are shown to describe the influence of mass scaling and frictional behavior. The paper describes the technical set‐up as well as the results of the FE simulation of this new bending technology.

Published
2004

4. Design and construction of the superconducting bending magnet for the injection system of the RIKEN SRC

Author

Akira Goto, H. Okuno, Y. Yano, T. Tominaka, and S. Fujishima

Subjects
Superconductivity, Quantitative Biology::Biomolecules, Engineering, business.industry, Cyclotron, Electrical engineering, Mechanical engineering, Curvature, law.invention, Bending magnets, Magnetic field, law, Dipole magnet, Booster (electric power), Physics::Accelerator Physics, business
Abstract

A K2500 superconducting ring cyclotron with 6-sectors is being constructed at RIKEN as an energy booster of the existing K540 ring cyclotron. The bending magnet for beam injection should be superconducting. Required fields are about 4 T and curvature of the coils is about 1.2 m. We developed test coils for the bending magnet. Their results are very promising for the real bending magnet. In the paper the results of the test coils and the design of the real bending magnets are described.

Published
2001