Dr. Simos Gerasimidis, an assistant professor in the Civil and Environmental Engineering Department, is receiving a $547,870 award from the highly coveted National Science Foundation Early Career Development (CAREER) Program. His CAREER project, titled “Auxetic Lattice Reinforcing Metamaterial Architectures for a New Class of Concrete Metastructures,” will exploit unique mechanical properties of architected metamaterials to create a new class of reinforced concrete structures, known as “metastructures,” with mechanical properties such as strength, ductility, and energy absorption superior to those available today.
As Gerasimidis explains, “Reinforced concrete is among the most commonly used structural materials in the world, and therefore significant improvements in its properties have transformative societal implications such as reducing costs, as well as increasing the quality and capabilities of structures.”
According to Gerasimidis, reinforced concrete metastructures, either designed directly from or influenced by architected metamaterials, combine material and architecture in unique ways to achieve previously unattainable properties.
Gerasimidis says that the NSF research he will conduct relies on a novel concrete confinement technique, which can be achieved through a unique mechanical property found in architected metamaterials. His research approach is to employ “auxetic” metamaterial lattice architectures as reinforcement and to demonstrate the utility of this new auxetically confined concrete for improving the performance of members within a building structural system.
Auxetic structures are those that, when stretched, become thicker perpendicular to the applied force and, when compressed, they shrink laterally to the applied force.
“Through material synthesis of the concrete matrix and the auxetic lattice,” says Gerasimidis, “a new composite will be created and a new auxetic confinement model will be developed in the inelastic range.”
To achieve this model, as Gerasimidis explains, he will pursue an integrated computational and experimental research program.
“Finally,” says Gerasimidis, “to upscale the auxetically confined concrete for building structures, the research program will employ additive manufacturing, digital fabrication, and automated robotic manufacturing techniques to efficiently manufacture auxetically confined concrete structural members.”
Gerasimidis adds that “Columns and shear-wall coupling beams will be designed and experimentally tested at our Brack Structural Testing Facility at UMass to demonstrate the capabilities of the new auxetically confined reinforced concrete, aiming at improved strength and ductility as well as increased shear strength and energy absorption.”
Part of the five-year project will also aim at enhancing the scientific literacy of underrepresented bilingual student groups by developing STEM programs for elementary students. In addition, new curriculum on metamaterials for civil metastructures will be developed enriching civil/structural engineering education.
The primary research interests of the Gerasimidis Research Group lie in the areas of architected metamaterials, shell buckling, infrastructure resilience, structural response of critical infrastructure systems subjected to extreme-loading events in urban regions, resilient-oriented structural design approaches, damage propagation, and structural response of damaged structures covering a broad spectrum of structural behavior.
Before Gerasimidis came to UMass, his five-year professional experience as a structural engineer included working on landmark, large-scale infrastructure projects such as the Olympic Stadium Steel Roof Structure in Athens, the most recent New York Yankees Stadium in the Bronx, the conceptual design of the Chicago Spire, and a steel footbridge in one of the most important Byzantine monuments of the world, the Thessaloniki Rotunda. (March 2021)