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Full-Text Articles in Engineering
Investigating The Effect Of Bead Geometry On Fiber Orientation And Thermomechanical Properties For Large-Format Extrusion-Based Additive Manufacturing, Joanna F. Keaton
Investigating The Effect Of Bead Geometry On Fiber Orientation And Thermomechanical Properties For Large-Format Extrusion-Based Additive Manufacturing, Joanna F. Keaton
Electronic Theses and Dissertations
In large-format extrusion-based additive manufacturing of polymer composites, the relationship between material properties and processing parameters requires further investigation. This thesis focuses on the relationship between fiber orientation and thermomechanical properties for short fiber-filled thermoplastic polymer systems manufactured by extrusion-based additive manufacturing. Fiber orientation is particularly important in determining the thermomechanical properties of the composite material as properties in the direction of deposition are expected to be higher for highly aligned fibers than randomly aligned fibers. Fiber orientation distribution, which is related to processing parameters and deposition conditions, can be efficiently represented by the orientation tensor. The orientation tensor can …
A Study On Early Age Properties Of Concrete For Precast And 3d Printing, Debalina Ghosh
A Study On Early Age Properties Of Concrete For Precast And 3d Printing, Debalina Ghosh
Doctoral Dissertations
Concrete is the second-most consumed material, leading the global Portland cement production of 4.1 billion tons in 2020 and 5-8% of global Carbon dioxide (CO2) emission annually. As with any other material and practice, the construction industry is also ever-changing to meet market demand, evolving technology, and resource limitation. In the case of concrete construction, one of the main concerns is the lack of automation. In the last few decades, some new construction methods have risen to address this concern. Some of these economic and successful practices are precast construction, self-compacting concrete (SCC), and 3D printing of concrete(3DPC). …
Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari
Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari
Electronic Theses and Dissertations
Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …
3d Printed Concrete & Polymer Concrete For Infrastructure Applications, Daniel Heras Murcia
3d Printed Concrete & Polymer Concrete For Infrastructure Applications, Daniel Heras Murcia
Civil Engineering ETDs
Additive manufacturing technology has been established as one of the fastest-growing building technologies worldwide. Three-dimensional concrete printing (3DCP) has developed an increasing interest in the last decade due to its prospects as a transformative technology for industries such as the concrete precast. Besides the improvements in automation technologies in construction, traditional construction has faced considerable challenges: high accident rates, labor dependency, significant potential for automation, and high costs associated with the use of traditional formwork. In this context, three-dimensional concrete, also referred to as physical prototyping, is a novel construction technique in which the concrete is extruded layer-to-layer. 3DCP is …
Extremely Low Cycle Fatigue Behavior Of Additively Manufactured 17-4ph Stainless Steel, Kaley Collins
Extremely Low Cycle Fatigue Behavior Of Additively Manufactured 17-4ph Stainless Steel, Kaley Collins
Civil Engineering Undergraduate Honors Theses
Steel structures survive seismic loading thanks to components capable of dissipating large amounts of energy through large deformations. Future optimizations of these components include complex free-form geometries that are difficult to fabricate with traditional casting processes. Additive manufacturing (AM) is an alternative for producing optimized free-form geometries. AM material contains significant differences in microstructural characteristics and mechanical behavior compared to its wrought counterparts. Research has been conducted to understand the effect of microscopic features in the high cycle fatigue (HCF) and low cycle fatigue (LCF) regimes. This study focuses on the behavior of 17-4 Precipitation Hardening (PH) stainless steel in …
Mechanical Performance Of Structural Systems With Missing Members: From Buildings To Architected Materials, Panagiotis Pantidis
Mechanical Performance Of Structural Systems With Missing Members: From Buildings To Architected Materials, Panagiotis Pantidis
Doctoral Dissertations
Structural systems are potentially subjected to damage initiating scenarios throughout the course of their service time. Depending on the nature and extent of the damaging event, they may experience significant reduction or even complete loss of their mechanical performance. This dissertation delves into the mechanics of structural systems under the notion of missing members from their domain, investigating types of structural systems: a) multi-story steel framed buildings, and b) materials with a truss-lattice microstructure. Part I of the dissertation investigates the performance of multi-story steel framed buildings under a column removal scenario, developing an analytical framework for their quasi-static robustness …