Possibilities of Measuring Stress and Health Monitoring in Materials Using Contact-Less Sensor Based on Magnetic Microwires (original) (raw)

Embedded ferromagnetic microwires for monitoring tensile stress in polymeric materials

Composites Part A: Applied Science and Manufacturing, 2014

Considerable efforts have been made to develop testing non-destructive methods for polymer composite materials. We would like to introduce researchers in the field of smart materials to a new method of monitoring internal stresses. The method can be classified as an embedded sensing technique, where the sensing element is a glass-coated ferromagnetic microwire with a specific magnetic anisotropy. With a diameter 10-100 lm, the microwire impedance acts as the controlled parameter which is monitored for a weak alternating current (AC) in the MHz range. The microwire impedance becomes stress sensitive in the presence of a weak constant axial bias magnetic field. This external parameter allows the impedance stress sensitivity to be easily tuned. In addition, a local bias field may also allow the reconstruction of stress profile when it is scanned along the microwire. The experimental results are analysed using simple magnetostatic and impedance models.

Novel sensing media based on ferromagnetic microwires for application to the remote imaging of the stress distribution

2003

In this research project we propose a new composite medium, which can visualise the mechanical stress at any stage: before and after damage. The main feature of the proposed stress-tuneable composite is its permittivity (dielectric constant), which depends on the mechanical stress. This kind of composite material can be characterised as a "sensing medium" that opens up new possibilities for remote monitoring of stress with the use of microwave transceiving techniques. The composite material can be made as a bulk medium or as thin cover to image the mechanical stress distribution inside construction or on its surface.

Non-Destructive Testing of Aircraft Structures Using Microwire-Based Tensile Stress Sensor

Applied Sciences

The development of non-destructive methods for material testing and diagnostics has been, in the last few decades, focused mainly on optical, infrared, thermography, ultrasonic, acoustic or X-ray principles. This article deals with the possibility of adaptation of magnetic sensors for the diagnostics of aircraft structures. The developed sensors are based on the enhanced induction method, allowing contactless diagnostics of the material structure. In the role of the sensing element, amorphous magnetic microwires were used. Thanks to their dimensions, microwires can either be placed on the material surface or be embedded directly into the composite material without structural violations. In the article, the measurement principles of the developed microwire-based tensile stress sensors, together with the experimental measurements with the sensors originally tested in the aircraft wing, are presented.

Novel magnetic microwires-embedded composites for structural health monitoring applications

Journal of Applied Physics, 2010

We report the results of a systematic study of the magnetic, mechanical, magnetoimpedance and field tunable properties of glass-coated amorphous Co 68.7 Fe 4 Ni 1 B 13 Si 11 Mo 2.3 microwires and composites containing these microwires. The magnetic microwires possess good magnetic and mechanical properties. The magnetoimpedance ratio in the gigahertz range varies sensitively with applied fields below the anisotropy field but becomes unchanged for higher applied fields. The good mechanical properties are retained in the magnetic microwires-embedded composites. The strong field dependences of the effective permittivity and transmission parameters in the gigahertz range indicate that the present composites are very promising candidate materials for structural health monitoring and self-sensing applications.

Ferromagnetic Resonance in Cast Microwires and its Application for The Non-Contact Diagnostics

Global Journal of Engineering Sciences, 2020

Ferromagnetic resonance in glass-coated Fe-based cast amorphous microwires reveals large residual stresses appearing in the microwire core during casting. These stresses, together with magnetostriction, determine the magnetoelastic anisotropy. Ferromagnetic resonance frequency is affected, in addition to residual and internal stresses, by external stresses applied to the microwire or a composite containing it (so-called stress effect). The dependence of ferromagnetic resonance frequency on the deformation of microwires is proposed to be used in the distant diagnostics of dangerous deformations of critical infrastructure objects and in medical application.

Optimization of magnetoimpedance and stress-impedance effects in single-microwire polymer composites for stress monitoring

2011

The influence of applied stress and the composite geometry on impedance properties of composites containing ferromagnetic microwires has been investigated. The results indicate that the application of tensile stress along the microwire axis and the increase of composite thickness decreased the magneto-impedance (MI) ratio. The stress induced impedance (SI) effect was enhanced with increasing composite thickness reflecting the role of the internal residual stresses. Theoretically calculated matrix-wire interfacial stress from the magneto-impedance profiles is in good agreement with the value of the applied effective tensile stress. This demonstrates a new route to probing the stress conditions of such composites.

FEM modeling of magnetic microwire and its using for stress monitoring inside the composite beam

Metalurgija, 2020

M. Spodniak, K. Semrád, M. Hovanec, P. Korba, T. Musil, Faculty of Aeronautics, Technical University of Kosice, Slovakia (e-mail: miroslav.spodniak@tuke.sk) The proposed article is devoted to the stress evaluation inside the composite beam using the embedded magnetic microwire sensors. The interlaminar stresses with high values can occur inside the composite structures during the operation. It is essential to monitor the stresses and to increase the lifetime of the composite materials by prediction using the research results from the stress distribution estimation and also during the operation using the embedded magnetic microwire-based sensors. In the article the results of the mechanical stress distribution between the magnetic microwire coating and core and the discussion about the experimental application of the magnetic microwire inside the composite beam are presented.

An Embedded Stress Sensor for Concrete SHM Based on Amorphous Ferromagnetic Microwires

A new smart concrete aggregate design as a candidate for applications in structural health monitoring (SHM) of critical elements in civil infrastructure is proposed. The cement-based stress/strain sensor was developed by utilizing the stress/strain sensing properties of a magnetic microwire embedded in cement-based composite (MMCC). This is a contact-less type sensor that measures variations of magnetic properties resulting from stress variations. Sensors made of these materials can be designed to satisfy the specific demand for an economic way to monitor concrete infrastructure health. For this purpose, we embedded a thin magnetic microwire in the core of a cement-based cylinder, which was inserted into the concrete specimen under study as an extra aggregate. The experimental results show that the embedded MMCC sensor is capable of measuring internal compressive stress around the range of 1–30 MPa. Two stress sensing properties of the embedded sensor under uniaxial compression were studied: the peak amplitude and peak position of magnetic OPEN ACCESS Sensors 2014, 14 19964 switching field. The sensitivity values for the amplitude and position within the measured range were 5 mV/MPa and 2.5 µs/MPa, respectively.