scholarly journals Determination of Plastic Material Properties of Thin Metal Sheets under Electromagnetic Forming Conditions

2021 ◽  
Author(s):  
Björn Beckschwarte ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Sheet Metal ◽  
Material Properties ◽  
Plastic Material ◽  
Electromagnetic Forming ◽  
Material Behavior ◽  
Process Conditions ◽  
Force Transmission ◽  
The Magnetic Field

Electromagnetic forming is a contactless high-speed forming technique. In this process force transmission is initiated by an electromagnetic field provided by a tool coil. While forming thin sheet metal, the magnetic field is present in the whole depth of the sheet metal by definition. Thus, the magnetic field generates eddy currents in the complete sheet volume. The resulting Lorenz` forces act as body forces and are used for forming. Thereby high strain rates, high temperatures and multiaxial stress fields influence the plastic material properties of the workpiece. In this study, the plastic properties were investigated under real electromagnetic forming conditions. By varying process conditions like charge energy, sheet thickness and die material, the magnetic field and thus the plastic material properties were changed. To visualize the influence of the electromagnetic field, forming experiments were carried out. The strain of the formed sheets was measured. Furthermore, the forming forces were determined by measurements during the electromagnetic forming as well as by finite element simulations. With the measured strain and the determined forming force, a model for the plastic material behavior during electromagnetic forming was evolved.

Investigating flexible textile-based coils for wireless charging wearable electronics

2019 ◽  
Vol 50 (3) ◽  
pp. 333-345 ◽  
Author(s):  
Danmei Sun ◽  
Meixuan Chen ◽  
Symon Podilchak ◽  
Apostolos Georgiadis ◽  
Qassim S Abdullahi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Dimensional Stability ◽  
Screen Printing ◽  
Wearable Electronics ◽  
Wireless Charging ◽  
The Magnetic Field ◽  
Screen Printed

Smart and interactive textiles have been attracted great attention in recent years. This research explored three different techniques and processes in developing textile-based conductive coils that are able to embed in a garment layer. Coils made through embroidery and screen printing have good dimensional stability, although the resistance of screen printed coil is too high due to the low conductivity of the print ink. Laser cut coil provided the best electrical conductivity; however, the disadvantage of this method is that it is very difficult to keep the completed coil to the predetermined shape and dimension. The tested results show that an electromagnetic field has been generated between the textile-based conductive coil and an external coil that is directly powered by electricity. The magnetic field and electric field worked simultaneously to complete the wireless charging process.

Increasing the effective affect of the magnetic field on the weld pool

2021 ◽  
pp. 29-33
Author(s):  
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Magnetic Fields ◽  
Weld Pool ◽  
Electromagnetic Effects ◽  
Weld Pools ◽  
The Magnetic Field

Variants of weld pools obtained by verification with the influence of magnetic fields are considered. Methods for increasing the effectiveness of electromagnetic effects during welding are proposed. Keywords: welding, electromagnetic field, weld pool, induction, coating. [email protected], [email protected]

A Proof of the Biot-Savart Law

1968 ◽  
Vol 72 (689) ◽  
pp. 437
Author(s):  
B. G. Newman
Keyword(s):  
Magnetic Field ◽  
Field Theory ◽  
Electromagnetic Field ◽  
Fluid Mechanics ◽  
Small Length ◽  
Line Vortex ◽  
Line Current ◽  
Electromagnetic Field Theory ◽  
The Magnetic Field

The Biot-Savart law gives the velocity associated with an elemental portion of line vortex, or the magnetic field associated with an elemental portion of line current. The following proof may appeal to students who approach fluid mechanics or electromagnetic-field theory from the engineering viewpoint. It will be stated in terms of fluid mechanics. Consider a very small length δs of line vortex of circulation strength Γ. At P(x) the velocity δV associated with this portion depends on Γ δs and x.

Effects of Electromagnetic Fields on the Quantum Yield of Free Radicals in Cryptochrome

2019 ◽  
Vol 953 ◽  
pp. 127-132
Author(s):  
Yu Ling Chen ◽  
Du Yan Geng ◽  
Chuan Fang Chen
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Free Radicals ◽  
Free Radical ◽  
Quantum Yield ◽  
Electromagnetic Fields ◽  
Applied Magnetic Field ◽  
Geomagnetic Field ◽  
Quantum Biology ◽  
The Magnetic Field

In this paper, the effects of the quantum yield of free radicals in cryptochrome exposed to different electromagnetic fields were studied through the quantum biology. The results showed that the spikes characteristics was produced in the free radicals in cryptochrome, when it exposed to the applied magnetic field (ω = 50 Hz, B0 = 50 μT). The spikes produced by the electromagnetic field was independent of the changes of polar θ. When the frequency of the magnetic field increased, the spikes characteristics produced in unit time also increased. These results showed that the environmental electromagnetic field could affect the response of organisms to the geomagnetic field by influencing the quantum yield in the mechanism of free radical pair.It provided a basis for studying the influence of environmental electromagnetic field on biology, especially the navigation of biological magnetism.

A Proposed Experiment of Direct Detecting of the Vector Potential within Classical Electrodynamics

1997 ◽  
Vol 11 (12) ◽  
pp. 531-540
Author(s):  
V. Onoochin
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Charged Particle ◽  
Vector Potential ◽  
Energy Exchange ◽  
Short Pulse ◽  
Classical Electrodynamics ◽  
Direct Influence ◽  
Ultra Short Pulse ◽  
The Magnetic Field

An experiment within the framework of classical electrodynamics is proposed, to demonstrate Boyer's suggestion of a change in the velocity of a charged particle as it passes close to a solenoid. The moving charge is replaced by an ultra-short pulse (USP), whose characteristics should depend on the current in the coil. This dependence results from the exchange of energy between the electromagnetic field of the pulse and the magnetic field within the solenoid. This energy exchange could only be explained, by assuming that the vector potential of the solenoid has a direct influence on the pulse.

ASTROID CURVES FOR A SYNTHETIC ANTIFERROMAGNETIC STACK IN AN APPLIED MAGNETIC FIELD

2009 ◽  
Vol 23 (20n21) ◽  
pp. 4021-4040
Author(s):  
D. M. FORRESTER ◽  
E. KOVACS ◽  
K. E. KÜRTEN ◽  
F. V. KUSMARTSEV
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Single Particle ◽  
Material Properties ◽  
Magnetic Particles ◽  
Particle System ◽  
Energy Landscape ◽  
Metastable States ◽  
Field Plane ◽  
The Magnetic Field

The interaction of two magnetic particles separated by an interlayer is illustrated through the "astroid" curves that represent regions in the magnetic field plane where different numbers of minima associated with stable or metastable states may exist. For a single particle, we describe the astroid curves of the Stoner-Wohlfarth model. The case of two particles is then examined and found to be much more complicated. The energy landscape of the two-particle system contains ferromagnetic, antiferromagnetic and canting states that emerge in response to the level of applied magnetic field. Because of this, up to four energy minima can exist in the system, depending upon the strength of the magnetic field and the material properties of the particles.

Simulation and Experimental Analysis of Magnetorheological Dampers Under Impact and Shock Loading

2015 ◽  
Author(s):  
Q. Ouyang ◽  
J. Wang ◽  
J. J. Zheng ◽  
X. J. Wang ◽  
Y. Xi
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Fluid Flow ◽  
Flow Field ◽  
Shock Loading ◽  
Coupling Effect ◽  
Mr Damper ◽  
Damping Force ◽  
Annular Gap ◽  
The Magnetic Field

Magnetorheological (MR) fluids contain suspensions that exhibit a rapid, reversible and tunable transition from a free-flowing state to a semi-solid state upon the application of an external magnetic field. This behavior has attracted significant attention in the development of dampers, shock absorption system, military and defence system and safety devices in aerospace engineering. However, many of the issues pertaining to MR damper behavior in impact and shock applications are relatively unknown. This study provides an experimental analysis and simulation analysis by using COMSOL multyphysics of MR dampers when they are subjected to impact and shock loading. To this end, a novel MR damper with a four-stage piston and independent input currents is designed and analyzed. In this paper, two-dimension symmetrical Computational Fluid Dynamics (CFDs) simulation for the laminar flow of an incompressible MR fluid in the annular gap in the presence of a varying magnetic field. The purpose of this research is to study the couple effect of electromagnetic field and the fluid flow field and magnitude of damping force in a macroscopic view. The governing differential equations describing the magnetic field and fluid flow in the annular gap are solved numerically by COMSOL Multiphysics. Through the electromagnetic analysis and flow field analysis, the coupling effect of the magnetic field between the coil and the multiphysics coupling effect of novel MR was be found. For the each coil has an independent power supply, so it can provide a wider range damping force by combining the electromagnetic field of coils.

scholarly journals A Highschooler’s Guide to GeV-Range Electromagnetism

2020 ◽  
Vol 02 (03) ◽  
pp. 2050013
Author(s):  
Satchit Chatterji ◽  
Aayush Desai ◽  
Aditya Dwarkesh ◽  
Anushree Ganesh ◽  
Ameya Kunder ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High School ◽  
Electromagnetic Field ◽  
High School Students ◽  
Empirical Relationship ◽  
Top Down ◽  
School Students ◽  
Force Equation ◽  
Independent Parameters ◽  
The Magnetic Field

The following article has been written primarily by the high school students who make up the team “Cryptic Ontics”, one of the two winning teams in the 2018 edition of CERN’s Beamline for Schools (BL4S) competition, and is based on the set of experiments the students endeavoured to conduct over the course of a two-week period at CERN. Reconstructing influential physical theories from scratch often helps in uncovering hitherto unknown logical connections and eliciting instructive empirical checkpoints within said theory. With this in mind, in the following article, a top-down reconstruction (beginning with the experimental observations and ending at the theoretical framework) of the Lorentz force equation is performed, and potentially interesting questions which come up are explored. In its most common form, the equation is written out as: [Formula: see text]. Only the term that includes the magnetic field [Formula: see text] will be dealt with for this article. The independent parameters we use are (i) the momenta of the particles, (ii) the charge (rather, the types) of particles, either positive or negative, and (iii) the current passing through the dipole generating the electromagnetic field. We then measure the angle by which particles get deflected while varying these three parameters and derive an empirical relationship between them.

scholarly journals Using the Carotazh Method to Determine the Electrical Characteristics of the Earth’s Subsoil

2021 ◽  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Surface Impedance ◽  
Electromagnetic Waves ◽  
Dielectric Permeability ◽  
Electrical Characteristics ◽  
Measuring Systems ◽  
The Earth ◽  
The Magnetic Field

Logging is a detailed study of the structure of the well incision by descent and ascent of a geophysical probe. It is often used to determine the electrical conductivity of terrestrial depths. To do this, the sides of the well deepen the electrodes, and they are fed into the depths of a constant electric current. However, if you use natural or artificial electromagnetic waves, it becomes possible to determine the dielectric permeability of terrestrial rocks at depth. To do this, the surface impedance is first measured on the surface of the earth, and then by measuring at a certain frequency of the electromagnetic field in the well hole, the electrical conductivity and dielectric permeability of terrestrial rocks are calculated by fairly simple formulas. Such measurements can be carried out by standard measuring systems, adding only a narrow frame with wire winding to measure the magnetic field.

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