Dynamics of a Bistable Mechanism with Parallel Beams and Permanent Magnets

2011 ◽  
Vol 308-310 ◽  
pp. 508-512
Author(s):  
Jian Zhao ◽  
Yu Huang ◽  
Ren Jing Gao ◽  
Hong Xi Wang
Keyword(s):  
Permanent Magnets ◽  
Magnetic Charge ◽  
Reaction Force ◽  
Mechanical Shock ◽  
Buckled Beams ◽  
Charge Model ◽  
Bistable Structure ◽  
Combined Structure ◽  
Bistable Mechanism ◽  
Elastic Reaction

Besides the three main categories of bistable mechanisms such as latch-lock mechanisms, hinged multisegment mechanisms, and residual-compressive-stress buckled beams, a novel unsymmetrical bistable mechanism with a combined structure of permanent magnets and mechanical beams is proposed, and the bistability of such combined structure is analyzed based on the magnetic-charge model and material mechanics theory. The nonlinear combined force during snap-through procedure is calculated accurately, which is in accordance with that obtained by the experiments. The bistable characteristics such as the threshold snapping force, the traveling range, stable positions, and the elastic reaction force at the stable position can be adjusted freely by changing the magnet structure parameters and the relative distance among the three magnets. Finally, the dynamic response is analyzed theoretically and experimentally, which shows that the bistable structure has a good frequency distinguishing capacity for mechanical shock pulses.

A Simple Magnetic Charge Model for Classification of Multiple Buried Metallic Objects in Cases With Overlapping Signals

2005 ◽  
Author(s):  
Fridon Shubitidze ◽  
Kevin O’Neill ◽  
Irma Shamatava ◽  
Keli Sun ◽  
Keith Paulsen
Keyword(s):  
Magnetic Charge ◽  
Charge Model

A Simple Magnetic Charge Model for Classification of Multiple Buried Metallic Objects In Cases With Overlapping Signals

2005 ◽  
Author(s):  
Fridon Shubitidze ◽  
Kevin O’Neill ◽  
Irma Shamatava ◽  
Keli Sun ◽  
Keith Paulsen
Keyword(s):  
Magnetic Charge ◽  
Charge Model

A Simple Magnetic Charge Model for Classification of Multiple Buried Metallic Objects in Cases with Overlapping Signals

2005 ◽  
Author(s):  
Fridon Shubitidze ◽  
Kevin O'Neill ◽  
Irma Shamatava ◽  
Keli Sun ◽  
Keith Paulsen
Keyword(s):  
Magnetic Charge ◽  
Charge Model

Design of a Constant-Force Flexure Micropositioning Stage With Long Stroke

2015 ◽  
Author(s):  
Qingsong Xu
Keyword(s):  
Parametric Design ◽  
Compliant Mechanism ◽  
Analytical Models ◽  
Constant Force ◽  
Force Output ◽  
Element Analysis ◽  
Flexure Mechanism ◽  
Bistable Structure ◽  
Bistable Mechanism ◽  
Long Stroke

This paper presents the design and analysis a flexure-guided compliant micropositioning stage with constant force and large stroke. The constant force output is achieved by combining a bistable flexure mechanism with a positive-stiffness flexure mechanism. In consideration of the constraint of conventional tilted beam-based bistable mechanism, a new type of bistable structure based on tilted-angle compound parallelogram flexure is proposed to achieve a larger range of constant force output while maintaining a compact physical size. To facilitate the parametric design of the flexure mechanism, analytical models are derived to quantify the stage performance. The models are verified by carrying out nonlinear finite-element analysis. Results demonstrate the effectiveness of the proposed ideas for a long-stroke, constant-force compliant mechanism dedicated to precision micropositioning applications.

Toward Accurate Design of a Transverse Flux Machine Using an Analytical 3-D Magnetic Charge Model

2015 ◽  
Vol 51 (11) ◽  
pp. 1-4 ◽  
Author(s):  
Maarten F. J. Kremers ◽  
Johannes J. H. Paulides ◽  
Elena A. Lomonova
Keyword(s):  
Magnetic Charge ◽  
Accurate Design ◽  
Charge Model ◽  
Transverse Flux

A Performance Prediction for Fe-Ga Magnetostrictive Strain Sensor

2016 ◽  
Author(s):  
JinHyeong Yoo
Keyword(s):  
Performance Prediction ◽  
Permanent Magnets ◽  
Stress Measurement ◽  
Strain Sensor ◽  
Tensile Load ◽  
Load Test ◽  
Mechanical Shock ◽  
Sensing Element ◽  
Poisson Effect ◽  
Dog Bone

This study will present a proof-of-concept non-contact strain sensor, utilizing a prototype magnetostrictive (Fe-Ga alloy, Galfenol) strip on a steel plate; coupled mechanical-magnetostrictive equations will be used to evaluate sensor performance prediction. In contrast with typical piezo-ceramic materials, Galfenol is ductile and has an excellent ability to withstand mechanical shock. Galfenol also changes its permeability in response to applied stress. This stress-based permeability change is not time dependent and can measure static loads. The variation of magnetic induction with stress depends strongly on bias magnetic field. Typically, the performance of Galfenol is measured in a compressional load region because it has higher response there. However, in this study, we are aiming to develop a sensor for tensile stress measurement. To achieve a compression load in the sensing element, a Galfenol strip is aligned perpendicular to a tension bar, so that tension in the bar creates compression in the strip, via the Poisson effect. The experimental setup in this study consists of a polycrystalline Galfenol strip bonded in the horizontal direction of a steel dog-bone shaped tension specimen. Two permanent magnets are attached at both ends of the Galfenol strip to provide a magnetic bias field through the strip. The magnetic flux through the Galfenol strip is measured with a non-contact Hall sensor during the tensile load test. The design reported here aims at low frequency applications, such as static and dynamic tension monitoring.

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