Bonding Glass Fiber-Reinforced Thermoplastic Composites using Localized Embedded Ultrathin Heaters for On-Orbit Assembly

Methods and technologies for on-orbit assembly are currently being actively researched and developed as a means to fabricate space structures larger than the constraints imposed by launch vehicles. For terrestrial applications, assembly techniques for materials such as thermoplastic composites via mechanical (bolts/rivets), thermal (fusion bonding/welding), or chemical (solvent/adhesive) methods are well established. This research explores the application of fusion bonding techniques for use in the space environment. To achieve the required heating in the absence of external sources, ultrathin resistance heaters are embedded in glass fiber thermoplastic composite pieces. A parametric investigation of the geometric design of these heaters via numerical simulation has been done to eventually reach an optimal design to minimize temperature variations throughout a single lap shear joint while minimizing surface area of the heater. The two adherends will be clamped together during heating. Localized heat from the heaters will melt the plastic at the joint and the adherends will be bonded together as the thermoplastic resolidifies. The bonded assembly will then be tested in tension to measure the shear strength of the bond.