Modelling of induction heating of thermoplastic composites using microscopic level modeling

In this article, a hybrid finite element model is presented for the simulation of induction heating of layered composite plates. Modeling includes the alternating electromagnetic field generated by an alternating current running through a coil, the current densities in the composite plate resulting from the electromagnetic field, the heat generation resulting from the current density distribution, and the heat transfer resulting from the nonuniform heat generation in the plate and the temperature distribution in the plate. The different elements of the model are shown to capture the time-dependent temperature distribution resulting from a coil moving over the surface of a composite laminate.

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Macroscopic modelling of induction heating of thermoplastic composites using computational electromagnetism

AIAA Scitech 2020 Forum ◽

10.2514/6.2020-2274 ◽

2020 ◽

Author(s):

Maximilian Holland ◽

Michael J. Van Tooren

Keyword(s):

Induction Heating ◽

Thermoplastic Composites ◽

Computational Electromagnetism

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Preparation of carbon fiber-reinforced polyimide composites via in situ induction heating

High Performance Polymers ◽

10.1177/0954008316667789 ◽

2016 ◽

Vol 29 (9) ◽

pp. 1027-1036 ◽

Cited By ~ 2

Author(s):

Chang Wei Liu ◽

Chun Yan Qu ◽

Lei Han ◽

De Zhi Wang ◽

Wan Bao Xiao ◽

...

Keyword(s):

High Temperature ◽

Carbon Fiber ◽

Induction Heating ◽

High Performance ◽

Thermoplastic Composites ◽

Heating Process ◽

Current Field ◽

Heating Method ◽

Polyimide Composites

Induction heating, a direct and contactless heating method, is generally more rapid and energetically more efficient than other heating methods used. In this work, we report the high-temperature imidization of carbon fiber/polyimide (PI) composites using an in situ induction heating method. Furthermore, we compare the advantages of the method to a conventional thermal procedure. The formed composites feature almost identical imidization rates, glass transition temperatures, and thermal oxidative stabilities cured at the same heating temperatures using a different heating process. Upon doping with ferriferous oxide, the ability of the magnetic nanoparticles in an alternating current field was studied to further drive the heating process and increase the rising and cooling time. The in situ induction heating process proves to be a powerful method for the high-temperature polymerization of high-performance thermoplastic composites, particularly for a PI matrix.

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A Study of Films Incorporating Magnetite Nanoparticles as Susceptors for Induction Welding of Carbon Fiber Reinforced Thermoplastic

Materials ◽

10.3390/ma13020318 ◽

2020 ◽

Vol 13 (2) ◽

pp. 318 ◽

Cited By ~ 3

Author(s):

Inseok Baek ◽

Seoksoon Lee

Keyword(s):

Carbon Fiber ◽

Induction Heating ◽

Weight Ratio ◽

Thermoplastic Composites ◽

Maximum Temperature ◽

Thermoplastic Resin ◽

Metal Mesh ◽

Manufacturing Method ◽

Lap Shear ◽

Heating Behavior

Induction welding is a fast, clean, noncontact process that often uses a metal-mesh susceptor to facilitate localized controlled heating; however, the metal mesh presents various problems. In this study, the induction heating behavior of a 450 μ m thick thin-film susceptor, fabricated by mixing magnetite (Fe 3 O 4 ) nanoparticles (NPs) and PA6/carbon fiber (CF) (30%) thermoplastic resin, was examined with respect to the weight ratio of Fe 3 O 4 (50, 67, 75, and 80 wt%). The useful induction heating behavior of the 75 wt% Fe 3 O 4 susceptor suggested its suitability for additional heat treatment experiments, carried out at 3.4 kW at a frequency of 100 kHz. This susceptor attained the same maximum temperature during 10 cycles of repeated induction heating and cooling. It was then used to weld two thermoplastic composites, with 60 s of induction heating followed by 120 s of simultaneous cooling and pressing. The resulting welded joints had lap shear strength values of 36.8, 34.0, and 36.4 MPa under tensile test loads of 884, 817, and 874 N, respectively. Scanning electron microscopy images confirmed a uniform weld quality. Thus, the proposed manufacturing method, involving the incorporation of Fe 3 O 4 NPs into thermoplastic resin, should help expand the range of applications for thermoplastic composites.

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Microscopic level modeling of induction welding heating mechanisms in thermoplastic composites

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211046648 ◽

2021 ◽

pp. 089270572110466

Author(s):

Darun Barazanchy ◽

Michel van Tooren ◽

Mohammod Ali

Keyword(s):

Cross Section ◽

Carbon Fibers ◽

Volume Fraction ◽

Circular Cross Section ◽

Microscopic Level ◽

Thermoplastic Composites ◽

Heating Process ◽

Fiber Volume ◽

Electrical Fields ◽

Solid Loss

Simulation and analysis of electromagnetic induction heating of continuous conductive fiber-based composite materials is used to (in)validate a series of hypotheses on the physics dominating the heating process. The behavior of carbon fibers with and without surrounding polymer in an alternating electromagnetic field is studied at a microscopic level in ANSYS Maxwell using the solid loss to quantify heat generation in the composite material. To limit the number of elements, the fibers are modeled with a polyhedron cross-section instead of a circular cross-section. In addition, each layer is modeled as an layer of fibers, e.g. 20 fibers placed next to each other. The simulations indicate that samples with fibers oriented in 0 and 90 orientation yield a substantial higher solid loss than fibers oriented in the 0 orientation only. The solid loss in both cases is however not enough to explain the level of heating observed in practice. Filling the volumes between fibers with polymer results in greater solid loss than samples with no polymer between the fibers, at equal fiber volume fraction. Note, no contact between fibers is modeled. The conductivity of the polymer is experimentally determined. The lab tests show relatively low finite resistance values in the transverse direction, indicating that the polymer in a composite should not be considered an isolator. The simulations seem to justify the conclusion that heating of thermoplastic composites in an alternating magnetic field rely on currents through the polymer. Without the polymer and subsequently no polymer conductivity, even if the electrical fields are strong there is almost no heat generated. The carbon fibers are required to be in proximity of each other to create the electrical fields that induce the current through the polymer. The heating is determined by the product of current density squared times the resistivity of the polymer.

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A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081188 ◽

1978 ◽

Vol 36 (2) ◽

pp. 64-65

Author(s):

K. Yoshida ◽

F. Murata ◽

S. Ohno ◽

T. Nagata

Keyword(s):

Mass Production ◽

Identical Condition ◽

Microscopic Level ◽

Electron Microscopic Level ◽

Electron Microscopic ◽

Simplified Method ◽

Complicated Process ◽

Critical Problems ◽

Electron Microscopic Radioautography ◽

Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

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Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053747 ◽

1982 ◽

Vol 40 ◽

pp. 216-217

Author(s):

D. J. McComb ◽

J. Beri ◽

F. Zak ◽

K. Kovacs

Keyword(s):

Microscopic Study ◽

Pituitary Adenomas ◽

Wistar Rats ◽

Microscopic Level ◽

Sprague Dawley ◽

Prolactin Cells ◽

Light Microscopic Level ◽

Ultrastructural Investigation ◽

Sprague Dawley Rats ◽

Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

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