Student: Jon MacArthur, Undergraduate Student in Aerospace Engineering, Iowa State University
Research Mentor: Wei Hong
Magnetic Double-Network Composites
My longest running project has been in the fascinating field advanced materials and composites. Alongside my mentor Dr. Wei Hong of the Iowa State University Aerospace Engineering Department, I have been helping research new, double-network composites for possible aerospace applications. These novel composites offer the benefit of high-strain elastomers coupled with the strength of a second stiffer network. For this project, I have aided in the development of magnetic double network composites that consist of an elastic material coupled with a magnetic second network that mitigates fracture of the softer network. This allows for high fracture tolerance in lightweight composites without expensive manufacturing processes.
I have conducted initial proof-of-concept tests on small-scale fiber mesh and elastic tape samples and characterized the results to compare to finite-element models. This work has included: composite layout design, fabrication, test design, testing, data analysis, and composite characteristic optimization. Thus far, they have shown excellent characteristics of a high fracture-tolerant, low-density composite. The composite was as stiff as the secondary mesh, and as stretchable as the elastic network. At certain compositions, it was found to be significantly stronger and tougher than the base material. The extensibility and toughness of the composite can be attributed to the damage delocalization mechanism similar to that of double network hydrogels. In the partially damaged phase, the stiff second network mesh fragments into small islands, surrounded by the highly stretched tape. Fundamentally, there is no reason this method of composite fabrication could not be applied to other materials such as ceramic or metal. Pursuing this research could potentially lead to lighter, stronger, and cheaper composites for future NASA and aerospace industry applications.