Thermal Analysis of In-Situ Curing for Thermoset, Hoop-Wound Structures Using Infrared Heating: Part I—Predictions Assuming Independent Scattering

Abstract

A curing process for unidirectional thermoset prepreg wound composite structures using infrared (IR) in-situ heating is investigated. In this method, the infrared energy is from all incident angles onto the composite structure to initiate the curing during processing. Due to the parallel geometry of filaments in wound composite structures, the radiative scattering coefficient and phase function within the structure depend strongly on both the wavelength and the angle of incidence of the IR incident radiation onto the fibers. A two-dimensional thermochemical and radiative heat transfer model for in-situ curing of thermoset, hoop-wound structures using IR heating is presented. The thermal transport properties that depend on the process state are also incorporated in the analysis. A nongray, anisotropic absorbing, emitting, and scattering unidirectional fibrous medium within a matrix of nonunity refractive index is considered. The temperatures and degrees of cure within the composite during processing are demonstrated numerically as a function of the configuration of IR heat source, nondimensional power input, mandrel winding speed, and size of wound composite. Comparison between the numerical result and experimental data is presented.

A helical tow model and numerical simulation of on-line thermal curing of thermoset composites in filament winding

“…The winding velocity (V t ¼ 0:2 m/s) and the diameter of the fiberwound composite structure (D ¼ 0:2 m) used in the present study for numerical result comparison are the same as those given in Ref. [3]. The comparison of the results are shown in Fig.…”

“…At the beginning of numerical calculation, a comparison between the present numerical results and the existing data [3] is made. Chern et al [3] studied in situ thermal curing of hoop-wound thermoset structure with infrared lamp. The prepreg tape with thickness of 0.132 mm is made of Hercules AS/3501-6.…”

“…The temperature and cure degree profiles in the present study are at the centerline of the tow and those in Ref. [3] are at the middle of each layer of tape. It is seen that the present numerical results agree well with Chern's data.…”

“…In the studies of curing of thermoset resin, a cure kinetics model for Hercules 3501-6 resin developed by Lee et al [15] has been widely used in engineering applications [1,3]. In this model, the heat release rate is defined as a function of cure degree and temperature.…”

“…Korotkov et al [2] presented a onedimensional (radial direction) heat transfer model for the simultaneous processes of filament winding and curing of thermoset composites in which the surface of the composite was heated by infrared irradiation and a heated mandrel. Chern et al [3] studied in situ curing for thermoset, hoop-wound structures using infrared heating. A two-dimensional (radial and azimuthal) model for infrared in situ curing was developed, in which the physical domain was mapped into a rectangular computational domain, neglecting the curvature of the surface layers.…”