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Author ORCID Identifier
https://orcid.org/0000-0001-8159-0345
AccessType
Open Access Dissertation
Document Type
dissertation
Degree Name
Doctor of Philosophy (PhD)
Degree Program
Civil and Environmental Engineering
Year Degree Awarded
2021
Month Degree Awarded
May
First Advisor
Kara D. Peterman
Second Advisor
Simos Gerasimidis
Subject Categories
Applied Mechanics | Civil Engineering | Other Materials Science and Engineering | Structural Engineering | Structural Materials
Abstract
Thin-walled structures have received a lot of interest during the last years due to their light weight, cost efficiency, and ease in fabrication and transportation, along with their high strength and stiffness. This dissertation focuses on the mechanical performance of thin-walled metallic structures from cold-formed steel shear walls and connections (PART I) to plate-lattice architected materials (PART II) via computational, experimental, and probabilistic methods. Cold-formed steel (CFS) shear walls subjected to seismic loads is the focus of PART I of this dissertation. An innovative three-dimensional shell finite element model of oriented strand board (OSB) sheathed CFS shear walls is introduced and benchmarked by nine different experimental studies. Particular attention is given to the fastener behavior since they are governed by significant inherent variability and they represent a dominant failure mechanism in CFS shear walls. Shear fastener behavior is experimentally determined and introduced into the finite element approach. To further address the connection variability, an extensive parametric analysis accompanied by Monte Carlo simulations are conducted. Design recommendations for higher capacity sheathings (fiber cement board (FCB) and steel-gypsum (SG) composite board) that are not currently enabled in design specifications are also introduced. Architected plate-lattice materials subjected to uniaxial compression is the focus of PART II of this dissertation. Architected materials are structures whose mechanical performance is governed by their geometry rather than their constituent material. Plate-lattices are composed of plates along the planes of crystalline structures. They represent the stiffest and strongest existing materials, since they can reach the Hashin-Shtrikman and the Suquet upper bounds. The stability and imperfection sensitivity of plate-lattices are evaluated in this work via elastic and plastic shell finite element analyses. Plate-lattice geometries of cubic symmetry are examined, such as the simple cubic (SC), the body-centered cubic (BCC), the face-centered cubic (FCC) structures and their combinations (SC-BCC, SC-FCC) over a range of relative densities between $\rho$*=0.5\% and $\rho$*=25\%. Imperfections are characterized by modal shapes at five different imperfection amplitudes. Finally, knockdown factors are recommended for these metamaterials.
DOI
https://doi.org/10.7275/22291381.0
Recommended Citation
Derveni, Fani, "Harnessing the Mechanics of Thin-Walled Metallic Structures: from Plate-Lattice Materials to Cold-Formed Steel Shear Walls" (2021). Doctoral Dissertations. 2174.
https://doi.org/10.7275/22291381.0
https://scholarworks.umass.edu/dissertations_2/2174
Included in
Applied Mechanics Commons, Civil Engineering Commons, Other Materials Science and Engineering Commons, Structural Engineering Commons, Structural Materials Commons