Engineering Commons^™

Size Scaling Of Strength And Toughness For 3d Printed Polymer Specimens, Darren Thomas Bell

Open Access Theses

To find material systems that offer low density and high strength, stiffness or toughness, hierarchically designed material systems have provided a promising research area. This thesis lays the groundwork for designing efficient micro-architectured material systems by characterizing size effects for 3d printed polymer parts. Two methods were used to analyze data from 3-point bend tests for specimens of varying size: the load-separation method was used for finding the point of crack growth initiation and Bazant’s method was used to find shape independent strength at failure. The strength values were used as inputs for finding size independent material constants within a …

A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox

Electronic Theses and Dissertations

We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external …

Additive Manufacturing Of Carbon Fiber-Reinforced Thermoplastic Composites, Nicholas M. Denardo

Open Access Theses

Additive manufacturing, or 3D printing, encompasses manufacturing processes that construct a geometry by depositing or solidifying material only where it is needed in the absence of a mold. The ability to manufacture complex geometries on demand directly from a digital file, as well as the decreasing equipment costs due to increased competition in the market, have resulted in the AM industry experiencing rapid growth in the past decade. Many companies have emerged with novel technologies well suited to improve products and/or save costs in various industries.

Until recently, the applications of polymer additive manufacturing have been mainly limited to prototyping. …

Improving The Mechanical Performance Of 3d Printed Parts Using Fused Filament Fabrication, Inderpreet Binning

Industrial and Manufacturing Engineering

The 3D printing industry has seen rapid growth in the last 10 years and has been called the next industrial revolution. There are several different processes used in 3D printing, but the most popular process is called Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM). This is the process where (most commonly) plastic filament enters a nozzle, is heated to a semi-liquid state, and then deposited into a pattern to create a print. One major drawback to this process is that the prints are anisotropic. This means that the strength of the print varies with the orientation that it …

A Concrete Water Pasteurization Device For Third World Countries, Andrea R. Murchie

Senior Honors Projects, 2010-2019

In the rural areas of South Africa, as well as many other developing countries, people cook food and sterilize their water by heating over open fires. Many times the fires are inside of homes, which more often than not are very small. Children will often be the ones to tend to the fire, out of necessity while parents and other family members are tending to other work and needs.

The purpose of my Senior Honors Project was to design a concrete vessel that can hold water and heat the water to pasteurization (149°F) when exposed to sunlight for an extended …

3d Printed Bone Supplement Materials, Azem Khalifa Yahamed

Dissertations

Three-dimensional (3D) printing is an advanced rapid technology that can be used to make human bone substitutes with exact shape and designed structures, based on models created from actual individual bone medical Digital Imaging and Communications in Medicine (DICOM) images. Biocompatible polymers have been selected for 3D printing of human bone structures. The thermoplastics were 3D printed with Fused Deposition Modeling (FDM) are Acrylate Butadiene Styrene (ABS), Polylactic Acid (PLA) and ULTEM 9085 (a polyetherimide). The polyamide PA 2200 was 3D printed using Selective Laser Sintering (SLS). Digital ABS (a crosslinked acrylic polymer) was 3D printed using PolyJet Technology. These …

A Novel Extrusion-Based Additive Manufacturing Process For Ceramic Parts, Amir Ghazanfari, Wenbin Li, Ming Leu, Gregory Hilmas

Faculty Publications, Mechanical Engineering

An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion (CODE) process, for producing three-dimensional ceramic components with near theoretical density is introduced in this paper. In this process, an aqueous paste of ceramic particles with a very low binder content (<1 vol%) is extruded through a moving nozzle at room temperature. After a layer is deposited, it is surrounded by oil (to a level just below the top surface of most recent layer) to preclude non-uniform evaporation from the sides. Infrared radiation is then used to partially, and uniformly, dry the just-deposited layer so that the yield stress of the paste increases and the part maintains its shape. The same procedure is repeated for every layer until part fabrication is completed. Several sample parts for various applications were produced using this process and their properties were obtained. The results indicate that the proposed method enables fabrication of large, dense ceramic parts with complex geometries.