Kawai Kwok, an associate professor in Purdue University’s School of Aeronautics and Astronautics, will be the primary investigator on a project with commercial software provider AnalySwift LLC. Source | Purdue University/Alan Cesar
According to Allan Wood, AnalySwift president and CEO, long-duration crewed missions to the moon, Mars and beyond require infrastructure, such as trusses, to be constructed sustainably on these surfaces. But there are immense logistical challenges in transporting heavy and large payloads to space.
“The AnalySwift project proposes a novel method of disassembling and reassembling thermoplastic composite joints in space,” Wood explains. “Our proposed method enables reconfiguration of truss structures in space, transitioning away from the current one-time use model to a scalable and sustainable approach.”
Kwok says spacecraft components could be quickly and easily repurposed into vastly different geometries. “For example, a lunar lander support truss could become a vertical solar array support truss,” he says. “There are other applications, depending on mission needs using the same set of structural elements and innovative multiphysics modeling.”
“This multiphysics modeling framework will simulate the debonding and bonding processes of thermoplastic composite joint-strut interfaces using embedded carbon nano-heaters.”
As part of the contract, AnalySwift will develop a composite heater layer for the trusses and other infrastructure, which will be embedded with nanostructured carbon fillers. The layer, to be made from the same thermoplastic matrix as the adhered composite parts, will bring the matrix to the processing temperature for interface debonding by mechanical forces.
“Lightweight, conductive, thin nanocarbon films will be encapsulated inside semicrystalline thermoplastics such as PEEK [polyetheretherketone],” explains Kwok. “The disassembled struts and joints will be reassembled to the repurposed configuration via resistance welding using the same or additional heaters. The proposed in situ heating and reassembly method enables spacecraft components to be reused, which greatly reduces the logistical footprint to deliver technologies to space.”
Liang Zhang, senior research scientist at AnalySwift, says the company will also develop better engineering tools for composites, enabling reliable multiphysics simulation of their technique to repurpose lightweight structures made from thermoplastics.
“Theoretical and computational developments will include a new software tool or module, Thermoplastic Composites Multiphysics,” Zhang adds. “This multiphysics modeling framework will simulate the debonding and bonding processes of thermoplastic composite joint-strut interfaces using embedded carbon nano-heaters.”
Kwok says the framework has broader applications for thermoplastics. “Advancements include developing multiphysics models and data for electrical heating and welding, including establishing relations between bonding strength and the process conditions of temperature, pressure and time. More specifically, the disassembly and assembly processes of a nanocomposite is simulated using a third-party commercial finite element code with user subroutines defining the governing behavior of the material system.”
Moreover, AnalySwift’s multiphysics simulation tool will determine force, pressure and temperature histories during assembly and disassembly processes. “More specifically, it will incrementally solve the constitutive relations as an initial value problem, extract temperature distributions at specific time points and calculate the time and power required for completion,” Zhang says.
While the processes and hardware advancements for disassembly and reassembly are more applicable to space applications, the software has other potential uses, notes Wood. “It can be particularly useful where simulation tools can improve use possibilities for high-performance thermoplastics,” he explains. “Additional applications can be likely for aerospace, defense, automotive, marine, energy, electronics, sporting goods and medical devices. Applications also extend beyond simulation and into repair for thermoplastics.”