The objective of this research proposal is to develop new coarse-grained molecular dynamics methods that can predict the response to both shear and hydrostatic stresses at atmospheric to extreme pressures at extreme strain rates. These harsh conditions are characteristic of the hydrodynamic loads subjected to marine surfaces in cavitating flows. To better understand the damage processes in polymeric coatings designed to protect marine components, such as propellers and rudders, coarse-grained molecular dynamics simulations are proposed to predict the evolution of stress and damage in polymers subjected to intense compression and shear forces at extreme strain rates. From these models, the effects of elastomer chemistry, chain length, and cross linking on resistance to cavitation erosion can be studied with coarse-grained molecular dynamics simulations. This research will attempt to answer the following questions: 1) Can additional many-body potentials (embedded atom potential) be used to simultaneously calibrate coarse-grained molecular dynamics to match the structural distributions and equation of state of their fully atomistic counterparts? 2) Can coarse-grained molecular dynamics simulations successfully predict the stress relaxation spectra of polymers at a range of pressures and temperatures and thus reduce the need to conduct challenging experiments at extreme strain rates and pressures? Potential Contributions to the Mission of the USN/USMC: Advanced polymers will lead to lighter, stronger, and multifunctional structures and protective coatings, and simulations that can predict material properties from polymer chemistry will greatly reduce the time required to create new materials tailored to address specific operational challenges. This proposal is innovative because it advances these capabilities by developing novel methodologies to predict the stress response of polymers in extreme loading conditions. The knowledge gained from this effort will advance the state-of-the-art in materials-by-design approaches for developing better coating materials to resist wear and failure of naval components.
|Effective start/end date||3/15/14 → 9/30/16|
- DOD-NAVY: Office of Naval Research (ONR): $140,000.00