Interfacial transport behaviors and their effects on thermal contact resistance between adhesive-bonded fiber-reinforced polymer composites

Abstract

3D-printed fiber-reinforced polymer composites show outstanding performances in many industrial applications, and adhesive bonding is suitable for joining the composites. However, the thermal contact resistance (TCR) can be critical for the thermal reliability and service life of polymer composites. Through a three-dimensional thermos-mechanical coupled modeling, this study focuses on the interfacial thermal transport behaviors of adhesive-bonded carbon fiber/reinforced polyamide 12 composites fabricated by 3D printing. The effects of different temperatures, pressures, and fiber angles on the bonding interface employing polyurethane adhesives are examined. The results indicate that the average thermal contact resistance (TCR) increases as interfacial temperature rises and pressure decreases, which is related to gap thickness and adhesive ratio. At a fiber angle of θ = 0°, the TCR of the bonding interface is always higher than that observed at θ = 90°. Increasing pressure leads to reduced gap thickness, increased adhesive ratio, and subsequently decreased TCR. When the pressure increases from 0 to 2.8 MPa, the TCR of the bonding interface decreases by 25.9%–44.9%. Among the selected conditions, the maximal TCR can be 2.2 times higher than the minimal TCR. This study is significant because it provides the knowledge of thermal conduction between adhesive-bonded polymer composites.