Engineering Commons^™

Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad

Dissertations, Master's Theses and Master's Reports

There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …

Molecular Modeling Of High-Performance Thermoset Polymer Matrix Composites For Aerospace Applications, Prathamesh P. Deshpande

Dissertations, Master's Theses and Master's Reports

The global efforts from major space agencies to transport humans to Mars will require a novel lightweight and ultra-high strength material for the spacecraft structure. Three decades of research with the carbon nanotubes (CNTs) have proved that the material can be an ideal candidate for the composite reinforcement if certain shortcomings are overcome. Also, the rapid development of the polymer resin industry has introduced a wide range of high-performance resins that show high compatibility with the graphitic surface of the CNTs. This research explores the computational design of these materials and evaluates their efficacy as the next generation of aerospace …

Development Of The Carbon Nanotube Thermoacoustic Loudspeaker, Troy Bouman

Dissertations, Master's Theses and Master's Reports

Traditional speakers make sound by attaching a coil to a cone and moving that coil back and forth in a magnetic field (aka moving coil loudspeakers). The physics behind how to generate sound via this velocity boundary condition has largely been unchanged for over a hundred years. Interestingly, around the time moving coil loudspeakers were first investigated the idea of using heat to generate sound was also known. These thermoacoustic speakers heat and cool a thin material at acoustic frequencies to generate the pressure wave (i.e. they use a thermal boundary condition). Unfortunately, when the thermoacoustic principle was initially discovered …

Molecular Modeling Of Aerospace Polymer Matrices Including Carbon Nanotube-Enhanced Epoxy, Matthew Radue

Dissertations, Master's Theses and Master's Reports

Carbon fiber (CF) composites are increasingly replacing metals used in major structural parts of aircraft, spacecraft, and automobiles. The current limitations of carbon fiber composites are addressed through computational material design by modeling the salient aerospace matrix materials. Molecular Dynamics (MD) models of epoxies with and without carbon nanotube (CNT) reinforcement and models of pure bismaleimides (BMIs) were developed to elucidate structure-property relationships for improved selection and tailoring of matrices.

The influence of monomer functionality on the mechanical properties of epoxies is studied using the Reax Force Field (ReaxFF). From deformation simulations, the Young’s modulus, yield point, and Poisson’s ratio …

Advanced Uses For Carbon Nanotubes: A Spherical Sound Source And Hot-Films As Microphones, Micaela M. Thiery

Dissertations, Master's Theses and Master's Reports

Super-aligned carbon nanotube (CNT) thin-film is used to create thermophones. The thermal properties of CNT film allow it to rapidly heat and cool when supplied AC power producing temperature and pressure gradients and, therefore, audible sound. The advantages of CNT thermophones include eliminating all moving components of traditional speakers and reducing the weight of the speaker itself by using CNT film, which is nearly weightless. Additionally, the flexibility of CNT film provides the unique opportunity to construct loudspeakers of various sizes and geometries. In this work, a spherical CNT thermophone is designed, manufactured, and tested for directivity with the overall …