The use of tubular composite structures has seen a dramatic increase over the years. This paper will discuss the thermal experimental study used, to develop an expandable RTM technique for fabrication of seamless composite tubes of very good quality. A thermal experiment was carried out on a mold setup, containing a braided preform and an expandable mandrel. The temperature of the Blue M oven containing the mold, expandable mandrel and thermocouples was raised to 80 degree C (176 degree F) and held at this temperature for two hours, thus duplicating the typical first cure cycle of the resin system used for this particular RTM process. Experimental data collected was used to plot a time-temperature curve, in order to determine the exact relationships between the instantaneous thermal expansion profile of the test components (steel mold, expandable mandrel). The temperature at the 2 hour time mark of the time-temperature curve in combination with the thermal expansion coefficient of the steel tube mold and Teflon rod were used to calculate the final internal diameter of the mold and the diameter of the solid Teflon rod. The difference between these measurements determines the theoretical thickness of the composite tube that can be molded. The composite tubes fabricated from the developed RTM technique using the appropriate resin injection systems, exhibited excellent dimensional uniformity, smoothness, and low void content.
Application of thermal experimental study to the development of expandable mandrel RTM technique for fabrication of seamless composite tubes
1998
12 Seiten, 9 Quellen
Aufsatz (Konferenz)
Englisch
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