The Office of Naval Research has awarded supplemental funding totaling just over $5.5 million to Brown Engineering Professors Yuri Bazilevs and Pradeep Guduru to build on existing research efforts aimed at the technical challenges in undersea mechanics. The University recently announced the formation of a research center for the Mechanics of Undersea Science and Engineering (MUSE), focused on leading the mechanics research on undersea vehicles and platforms; training, educating and empowering new and diverse generations of scientists and engineers to meet the technical challenges of the U.S. Navy and more; and integrating with the Naval research and development ecosystem in Rhode Island and beyond. Bazilevs serves as the initial director of the center along with co-directors Guduru and Professor Kenny Breuer. These awards are additional funding awarded to Bazilevs and Guduru to build on research in their areas of expertise.
Predictive Modeling and Simulation for Next Generation Naval Undersea Vehicles and Platforms
As principal investigator for predictive modeling and simulation for next generation naval undersea vehicles and platforms, Bazilevs and co-investigators Miguel Bessa, Guduru, Dan Harris and Vikas Srivastava will expand the advanced physical modeling and simulation framework, covering four specific areas to address, through the development of modeling and simulation methods as well as the experimental investigations, the technical challenges involved in these applications. These areas include multiscale framework for laminated fiber-reinforced polymer composite structures tailored to undersea vehicles; high-fidelity modeling framework for underwater explosion fluid-structure interaction; modeling for design and control of autonomous vehicles near air-water interfaces; and neural inverse design of structures for extreme mechanical events. This $2.78 million award is in addition to the $4.68 awarded in this area in 2021, extends through 2026, and also includes Avinash Dongare from the University of Connecticut and Jinhui Yan from the University of Illinois Urbana-Champaign.
The fiber-matrix interface plays a crucial role in the performance of fiber reinforced polymer (FRP) composites. The fiber and matrix interface properties can significantly degrade under prolonged extreme environmental conditions, and the researchers will study the FRP composites through experimental investigation, micro-mechanical modeling and structure computations, as well as energy-absorbing new composites, including metal-ceramic 3D architecture composites and polymers as layered composites. A computational study to test and predict the dynamic response of FRPs will aim to characterize the composites using high-throughput atomic scale and mesoscale simulations.
A level-set approach will be developed and validated, suitable for compressible flows, to track the interface between seawater and explosive gas products, which will significantly enhance the efficiency of underwater explosive scenarios, while work focusing on characterizing the drag of partially submerged objects through experiments, numerical simulations, and reduced-order modeling across a broad range of parameters, including individual contributions to the total drag and include form drag, skin friction, wave drag and hydrostatic forces will be continued.
Finally, the collaborators will address a long standing challenge of controlling the neural reparameterization capabilities of gradient-free algorithms and their ability to learn from training data with artificial neural networks. Developing new approaches for inverse design will open avenues to find structures with unprecedented performance, replacing the more common trial-and-error discovery process.
Undersea Vehicle Science and Technologies: Multifunctional Structural Batteries, Materials for Extreme Environments and Multi-Metal Additive Manufacturing
Guduru and co-investigators Srivastava, David Henann, Haneesh Kesari, Bazilevs, Bessa, and Lucas Caretta, along with Naba Karan from the University of Connecticut were awarded $2.7 million over the next four years. This supplemental funding will be used to build on an existing research effort that aims to develop the necessary science and technology to help undersea vehicles become lighter and more maneuverable, and resist failure under the extreme environments and loading scenarios where they are expected to operate. Guduru had previously been awarded $1.8 million over three years toward this effort, beginning in 2021 and an additional $1.85 million in 2022.
He and his collaborators will continue with three interdisciplinary and collaborative research efforts that synergistically combine experimentation, theory and computation including multifunctional solid state lithium ion batteries; designing, fabricating and characterizing light-weight structural composite materials with engineered meso-scale architectures for extreme environments; and experimentally studying and mathematically modeling microscopic and macroscopic soft tissue and cell damage under impact and shock loads.
Solid state batteries hold enormous promise towards realizing intrinsically safer alternatives to conventional lithium ion batteries with higher energy density that can meet the Navy’s current and future onboard stored energy and power demands. Investigators aim to develop a hybrid composite design concept using high voltage active cathodes to increase the active cathode mass loading with the target of going beyond 2 mAh/sq.cm. The composite cathode formulation will utilize a solid polymer electrolyte to increase solid-interfacial contact that is expected to be beneficial for increased active mass loading in the composite structure. The configuration will be optimized for impedance and safety. Additionally, a multi-layered solid electrolyte concept will be explored to overcome the performance limitations of the state of the art.
Collaborators also are investigating the design, fabrication and characterization of light-weight structural composite materials that can deliver superior performance under extreme loading conditions such as shock, blast or impact loading. The goal is to employ multi-material additive manufacturing science and technologies to fabricate high-performance lightweight materials and to engineer composite mesostructures to withstand a wide range of quasistatic and dynamic loading at high pressures, strain rates and temperature. Such engineered meso-architected materials will be of immense benefit to the Navy for protection of structures in harsh environments. The effort will combine fabrication of meso-scale architected materials, experimental characterization, theoretical and computational modeling to optimize resistance to failure modes such as fracture and localization and employ machine learning methods for arriving at optimal 3D architectures.
The effort also aims to develop a comprehensive understanding of the mechanisms of mechanical damage, micro/macro fractures in soft tissues, and the loss of cell functions (cell injury) due to applied loads. Guduru and his collaborators will experimentally study and mathematically model microscopic and macroscopic soft tissue deformation and damage, accomplished through in vitro mechanical experimentation on tissue and tissue-mimicking gels, as well as study injury at the cell level and develop predictive cell injury models linked with the above continuum tissue scale damage models. Underwater shock waves or blunt impacts can cause serious injury to marine mammals and sub-sea surface warfighters, including marine divers, navy members in a submarine, and navy members inside a vessel. The mechanical loads from a shock wave or blunt impact cause damage to the tissues and extracellular matrix and injury to cell populations. Mechanics play an important role in the soft tissue response, damage, and pathophysiology of traumatic brain injury, pulmonary hemorrhage and edema, and GI hemorrhaging. At the fundamental level, the injuries result from an applied load causing microscopic and macroscopic damage in a soft material.