Survival of actively cooled microvascular polymer matrix composites under sustained thermomechanical loading

• Published in: Composites. Part A, Applied science and manufacturing Applied science and manufacturing, 2016-03, Vol.82, p.170-179
• Main Authors: Coppola, Anthony M., Warpinski, Luke G., Murray, Sean P., Sottos, Nancy R., White, Scott R.
• Format: Article
• Language: English
• Subjects: B. High-temperature properties; B. Thermomechanical; Channels; Cooling; D. Thermal analysis; Heat flux; Heat transfer; Heating; Networks; Polymer matrix composites; Survival; Vascular cooling
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2015.12.010

Exposure to high heat can cause polymer matrix composites (PMC) to fail under mechanical loads easily sustained at room temperature. However, heat is removed and temperature reduced in PMCs by active cooling through an internal vascular network. Here we compare structural survival of PMCs under thermomechanical loading with and without active cooling. Microchannels are incorporated into autoclave-cured carbon fiber/epoxy composites using sacrificial fibers. Time-to-failure, material temperature, and heat removal rates are measured during simultaneous heating on one face (5–75kW/m2) and compressive loading (100–250MPa). The effects of applied compressive load, heat flux, channel spacing, coolant flow rate, and channel distance from the heated surface are examined. Actively cooled composites containing 0.33% channel volume fraction survive without structural failure for longer than 30min under 200MPa compressive loading and 60kW/m2 heat flux. In dramatic comparison, non-cooled composites fail in less than a minute under the same loading conditions.