EMWorks Newsletter 2019 EMWorks Newsletter 2019

THERMAL INVESTIGATION OF CRACK DETECTION BY EDDY CURRENT THERMOGRAPHY METHOD

Eddy current pulsed thermography ECPT : Active Infrared thermography method, based on induction heating phenomenon, is immensely developing for NDT due to its reliability and accuracy in material defect inspection.

In this study, the effectiveness of ECPT technique has been investigated numerically using FEM method. The analyzed model consists of spiral coil enrolled around a U-shaped ferrite core. A schematic illustration of the ECPT technique with the studied 3D design are shown respetively in Figures 1a) and 1b).

The AC magnetic module of EMS is used in this analysis, coupled to the transient thermal solver, to compute and visualize the eddy current and temperature distribution around the specimen crack. The semi-elliptical crack shape is illustrated in the Figure 2.

Figure 2 - Geometry of the tested plate containing a semi-elliptical surface-breaking crack [1]

After 500 ms of induction heating, the simulation revealed the results shown below. The current density distribution around the crack on the specimen surface shows a clear perturbation of eddy currents. The flow directions of currents are changed by the crack, leading to the surface being unevenly heated.

The generated temperature is shown in the Figure 5. The temperature of the central region of the U-shaped core on the specimen is almost evenly distributed. The maximum value is dedicated to the crack contours, reaching 23.13 °C, which is in a good coincidence with Reference [1] results (23.5 C).

Figure 1 - a) Schematic illustration of the ECPT [1]

b) 3D design of the studied model

Since eddy current are localized across the skin depth of the tested plate, a fine mesh was applied to the top surface of the specimen and to the crack using the mesh control feature of EMS.

Figure 3 - Meshed model

Figure 4 - Vector plot of current density distribution

The Figure 6 shows the heated air part delimited by the crack. The temperature at the end points of the defect is much higher than that at the other parts, and it sharply decreases in the depth direction. These characteristic features are used to predict the length of the crack from the two peak temperature points of the edges, and to determine the temperature difference between the crack and the other parts.

Figure 5 - Temperature distribution


 

Figure 6 - Temperature distribution across the crack


 

EMS ANALYSES - THERMAL COUPLING

EMS comes with an integrated thermal steady-state and transient solver. EMS automatically computes the joule, eddy, and core losses and feeds them into the thermal solver. You may readily add non-electromagnetic heat loadings by applying volume heat, heat flux, or simply fixed temperature. Considering the environment conditions such as convection and radiation, EMS thermal steady-state and transient computes the temperature, temperature gradient, and heat flux and saves them to "Thermal Results" folder. Since the thermal solver is integrated in the electromagnetic solvers, it uses the same model and mesh. There is no need to export and import any data.

Figure 7 : Temperature distribution in automotive fuse


SCIENCE NEWS

3D Heart Simulation Predicts How Drugs Will Affect Your Heartbeat

Your heart might “skip a beat” if you’re frightened or you suddenly see a long-lost love, but in real life, an irregular heartbeat can be dangerous. If the heart can't pump enough blood to the body, it could result in organ failure or stroke. And certain prescription drugs may throw off the natural rhythm of your heart if not properly vetted. To make sure new drugs don’t cause these deadly side effects, scientists have built a 3D model of the human heart. Composed of 22 million "cells," the model simulates the heart’s activity from the molecular level to the organ level--from the ion channels in cell membranes, for example, to the muscle contractions that pump blood.

EVENTS

MAY 21 - CWIEME BERLIN 2019
MESSE BERLIN

The world’s largest electric motor and transformer manufacturing event. For over 23 years, the CWIEME exhibition and conference has been at the forefront of the global electric motor,generator, transformers and EV market. Visit us at Booth number Hall 1_2, Stand C53.

JUNE 2-7 - IMS 2019
BOSTON, MASSACHUSETTS

Join us in Boston, 2-7 June 2019 for IMS2019! The IEEE Microwave Theory and Techniques Society’s 2019 IMS Microwave Week will be held 2-7 June 2019 in Boston, Massachusetts. Visit us at Booth #161.

JUNE 15-19 - ASEE 2019
TAMPA, FLORIDA

Join us for the 126th Annual Conference & Exposition! Tampa Convention Center Tampa, Florida June 15 - 19, 2019
Visit us at Booth #230.