Collaborative Research: Uncovering Ballistic Plasticity and Failure Mechanisms of Elastomeric Polymers

Elastomeric polymers are widely used in various industries, ranging from biomedical devices to automotive safety systems, due to their flexibility, durability, and ability to absorb energy. However, current understanding holds that these materials respond primarily in a highly elastic manner and tend to fail in a brittle fashion under extreme conditions. Research supported by this project aims to transform that understanding by uncovering how elastomers behave when subjected to extremely high deformation rates, such as those experienced in ballistic or shock-loading environments. By doing so, this research looks to provide insight into the ability of elastomeric polymers to undergo permanent, plastic deformation, contrary to conventional belief. These findings could lead to the design of new polymer-based structures with improved performance in impact mitigation, flexible electronics, and rapid manufacturing. Additionally, the project will contribute to training students in cutting-edge experimental and computational techniques, integrating research into engineering education, and promoting an exchange program between the two research laboratories. This research investigates the mechanisms of plastic deformation and failure in elastomeric polymers under ultra-high strain-rate loading using a novel laser-based shock technique coupled with bulk spectroscopy that can strategically shape and tune the rate of deformation. The experimental approach enables repeated shock loading of the same location to simulate and study shock fatigue and damage accumulation. Through advanced characterization methods, including spectroscopy, microscopy, and thermal and mechanical testing, the project seeks to reveal how molecular networks evolve under extreme conditions. These observations look to inform the development of a new multiscale computational model that couples molecular-scale deformation, damage accumulation, and rate-dependent mechanical response. The model intends to incorporate thermodynamic principles and micromechanical behavior to predict how different classes of elastomeric polymers behave under shock loading. The combination of experimental discovery and theoretical modeling is expected to produce a fundamental shift in the understanding of polymer plasticity and damage evolution, with broad applications across manufacturing, defense, and biomedical fields. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.