Browsing by Subject "additive manufacturing"
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Item 3D Printed ABS and Carbon Fiber Reinforced Polymer Specimens for Engineering Education(Springer, 2016) Golub, Michael; Guo, Xingye; Jung, Mingyo; Zhang, Jing; Department of Mechanical Engineering, School of Engineering and TechnologyThree 3D printed plastic materials, ABS, ABS plus, and CFRP, have been studied for their potential applications in engineering education. Using tensile test, the stress strain curves of the materials have been measured. The Young’s modulus, ultimate strength, and fracture toughness of the materials are calculated from the stress strain curve. The results show that CFRP has the highest stiffness or Young’s modulus. ABS plus has strongest mechanical properties, with highest ultimate strength and fracture toughness. With the measured properties, the 3D printed samples are a viable solution for engineering students to learn mechanical properties of materials.Item 3D printing in surgical simulation: emphasized importance in the COVID-19 pandemic era(Future Medicine, 2021-03-01) Michaels, Ross; Witsberger, Chelsey A; Powell, Allison R; Koka, Krishna; Cohen, Katheryn; Nourmohammadi, Zahra; Green, Glen E; Zopf, David A; Otolaryngology -- Head and Neck Surgery, School of MedicineHistorically, surgical training was an apprenticeship model of see one, do one, teach one. However, a proficiency-based training approach has become increasingly implemented for assessing surgical skills with performance scores used as benchmarks to track trainee proficiency [1]. Surgical simulators are starting to be utilized more to assess proficiency in trainees on certain procedures with many residency programs having simulation as a piece of their training curriculum. Today, simulation in surgical training takes many forms. Live animals and cadavers are often implemented since these simulators can simulate operating on realistic tissue and on human anatomy respectively. There are also basic simulators that are models that simulate a component of an operation such as suturing or knot-tying. These help trainees practice certain surgical skills necessary for completing a procedure. Some of these simulators have become more complex and simulate several steps or even an entire procedure such as joint replacements and fixating fractures [1]. With the increased availability in 3D printing technology and a push toward personalized medicine, 3D printing research has exponentially increased in recent years and has been an area of investigation for the development of surgical simulators [2]. Using a 3D printer to construct models for simulation leads to vast opportunity to customize the simulator while significantly reducing cost. Prior to the advent of 3D printing and additive manufacturing, computed tomography (CT) data were used to construct anatomic models using subtractive manufacturing with the first model made in 1979 [3]. Commercial 3D printers became available in the 1980s and were introduced into the medical field in 1994 [4]. Currently, 3D printing has several surgical applications including anatomic models for surgical planning, simulation and education; implants and prostheses; and surgical guides [3].Item 3D Printing of Human Ossicle Models for the Biofabrication of Personalized Middle Ear Prostheses(MDPI, 2022-10-31) Dairaghi, Jacob; Rogozea, Dan; Cadle, Rachel; Bustamante, Joseph; Moldovan, Leni; Petrache, Horia I.; Moldovan, Nicanor I.; Physics, School of ScienceThe middle ear bones (‘ossicles’) may become severely damaged due to accidents or to diseases. In these situations, the most common current treatments include replacing them with cadaver-derived ossicles, using a metal (usually titanium) prosthesis, or introducing bridges made of biocompatible ceramics. Neither of these solutions is ideal, due to the difficulty in finding or producing shape-matching replacements. However, the advent of additive manufacturing applications to biomedical problems has created the possibility of 3D-printing anatomically correct, shape- and size-personalized ossicle prostheses. To demonstrate this concept, we generated and printed several models of ossicles, as solid, porous, or soft material structures. These models were first printed with a plottable calcium phosphate/hydroxyapatite paste by extrusion on a solid support or embedded in a Carbopol hydrogel bath, followed by temperature-induced hardening. We then also printed an ossicle model with this ceramic in a porous format, followed by loading and crosslinking an alginate hydrogel within the pores, which was validated by microCT imaging. Finally, ossicle models were printed using alginate as well as a cell-containing nanocellulose-based bioink, within the supporting hydrogel bath. In selected cases, the devised workflow and the printouts were tested for repeatability. In conclusion, we demonstrate that moving beyond simplistic geometric bridges to anatomically realistic constructs is possible by 3D printing with various biocompatible materials and hydrogels, thus opening the way towards the in vitro generation of personalized middle ear prostheses for implantation.Item A Novel Framework for Predictive Modeling and Optimization of Powder Bed Fusion Process(MDPI, 2021-10) Marrey, Mallikharjun; Malekipour, Ehsan; El-Mounayri, Hazim; Faierson, Eric J.; Agarwal, Mangilal; Mechanical and Energy Engineering, School of Engineering and TechnologyPowder bed fusion (PBF) process is a metal additive manufacturing process which can build parts with any complexity from a wide range of metallic materials. PBF process research has predominantly focused on the impact of only a few parameters on product properties due to the lack of a systematic approach for optimizing a large set of process parameters simultaneously. The pivotal challenges regarding this process require a quantitative approach for mapping the material properties and process parameters onto the ultimate quality; this will then enable the optimization of those parameters. In this study, we propose a two-phase framework for optimizing the process parameters and developing a predictive model for 316L stainless steel material. We also discuss the correlation between process parameters -- i.e., laser specifications -- and mechanical properties and how to achieve parts with high density (> 98%) as well as better ultimate mechanical properties. In this paper, we introduce and test an innovative approach for developing AM predictive models, with a relatively low error percentage of 10.236% that are used to optimize process parameters in accordance with user or manufacturer requirements. These models use support vector regression, random forest regression, and neural network techniques. It is shown that the intelligent selection of process parameters using these models can achieve an optimized density of up to 99.31% with uniform microstructure, which improves hardness, impact strength, and other mechanical properties.Item Additive Manufacturing of Metallic Materials: A Review(Springer, 2017) Zhang, Yi; Wu, Linmin; Guo, Xingye; Kane, Stephen; Deng, Yifan; Jung, Yeon-Gil; Lee, Je-Hyun; Zhang, Jing; Mechanical Engineering, School of Engineering and TechnologyIn this review article, the latest developments of the four most common additive manufacturing methods for metallic materials are reviewed, including powder bed fusion, direct energy deposition, binder jetting, and sheet lamination. In addition to the process principles, the microstructures and mechanical properties of AM-fabricated parts are comprehensively compared and evaluated. Finally, several future research directions are suggested.Item Characterization of tensile and hardness properties and microstructure of 3D printed bronze metal clay(2017) Golub, Michael; Zhang, JingBronze is a popular metal for many important uses. Currently, there are no economical 3D printers that can print Bronze powders. A recent product, Bronze Metal Clay (BMC) has arrived. Additionally, commercial metal 3D printers require laser or electron beam sources, which are expensive and not easily accessible. The objective of this research is to develop a new two-step processing technique to produce 3D printed metallic component. The processing step includes room temperature 3D printing followed by high-temperature sintering. Since no material data exists for this clay, the tensile strength and hardness properties of BMC are compared to wrought counterpart. In this research tests are completed to determine the mechanical properties of Cu89Sn11 Bronze Metal Clay. The author of this thesis compares the physical properties of the same material in two different formats: 3D printed clay and molded clay. Using measured stress-strain curves and derived mechanical properties, including Young's modulus, yield strength, and ultimate tensile strength, the two formats demonstrate inherit differences. The Ultimate tensile strength for molded BMC and 3D-printed specimens sintered at 960 C was 161.94 MPa and 157 MPa, respectively. A 3D printed specimen which was red at 843 C had 104.32 MPa tensile strength. Factory acquired C90700 specimen had an ultimate stress of 209.29 MPa. The Young's modulus for molded BMC and 3D-printed specimens sintered at 960 C was 36.41 GPa and 37.05 GPa, respectively. The 843 C 3D-printed specimen had a modulus of 22.12 GPa. C90700 had the highest modulus of 76.81 GPa. The Yield stress values for molded BMC and 3D-printed specimens sintered at 960 C was 77.81 MPa and 72.82 MPa, respectively. The 3D-printed specimen had 46.44 MPa. C90700 specimen had 115.21 MPa. Hand molded specimens had a Rockwell hardness HRB85, while printed samples had a mean of HRB69. Also, molded samples recorded a higher Young's Modulus of 43 GPa vs. 33 GPa for the printed specimens. Both samples were weaker than the wrought Cu88:8Sn11P0:2 which had a 72 GPa. Cu88:8Sn11P0:2 also was a harder material with an HRC45. The property di erence between 3D printed, molded, and wrought samples was explained by examining their micro structures. It shows that 3D printed sample had more pores than the molded one due to printing process. This study demonstrates the flexibility and feasibility of using 3D printing to produce metallic components, without laser or electron beam source.Item Characterization of tensile, creep, and fatigue properties of 3D printed Acrylonitrile Butadiene Styrene(2016-08) Zhang, Hanyin; Zhang, Jing; Ryu, Jong Eun; Jones, Alan S.; Anwar, SohelAcrylonitrile Butadiene Styrene (ABS) is the most widely used thermoplastics in 3D printing for making models, prototypes, patterns, tools and end-use parts. However, there is a lack of systematic understanding of the mechanical properties of 3D printed ABS components, including orientation-dependent tensile strength, creep, and fatigue properties. These mechanical properties are critically needed for design and application of 3D printed components. The main objective of this research is to systematically characterize key mechanical properties of 3D printed ABS components, including tensile, creep, and fatigue properties. Additionally, the eff ects of printing orientation on the mechanical prop- erties are investigated. There are two research approaches employed in the thesis: rst, experimental investigation of the tensile, creep, and fatigue properties of the 3D printed ABS components; second, laminate based finite-element modeling of tensile test to understand the stress distributions in different printing layers. The major conclusions of the thesis work are summarized as follows. The tensile test experiments show that the 0 printing orientation has the highest Young's modulus, 1.81 GPa, and ultimate strength, 224 MPa. The tensile test simulation shows a similar Young's modulus as the experiment in elastic region, indicating the robustness of laminate based finite element model. In the creep test, the 90 printing orientation has the lowest k value of 0.2 in the plastics creep model, suggesting the 90 is the most creep resistant among 0 , 45 , and 90 printing orientations. In the fatigue test, the average cycle number under load of 30 N is 3796 revolutions. The average cycle number decreases to 128 revolutions when the load is below 60N. Using the Paris Law, with the crack size of 0.75 mm long and stress intensity factor is varied from 352 to 700 MN -m^3/2 , the predicted fatigue crack growth rate is 0.0341 mm/cycle.Item A Combined Modeling and Experimental Study of Tensile Properties of Additively Manufactured Polymeric Composite Materials(Springer, 2020) Meng, Lingbin; Yang, Xuehui; Salcedo, Eduardo; Baek, Dong-Cheon; Ryu, Jong Eun; Lu, Zhe; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyIn this study, the mechanical properties, in terms of stress–strain curves, of additively manufactured polymeric composite materials, Tango black plus (TB+), vero white plus (VW ), and their intermediate materials with different mixing ratios, are reported. The ultimate tensile strength and elongation at break are experimentally measured using ASTM standard tensile test. As the content of VM+ increases, the strength of the polymeric materials increases and elongation decreases. Additionally, the Shore A hardness of the materials increases with reduced TB+ concentration. In parallel to the experiment, hyperelastic models are employed to fit the experimental stress–strain curves. The shear modulus of the materials is obtained from the Arruda–Boyce model, and it increases with reduced concentration of TB+. Due to the good quality of the fitted data, it is suggested that the Arruda–Boyce model is the best model for modeling the additively manufactured polymeric materials. With the well characterized and modeled mechanical properties of these hyperelastic materials, designers can conduct computational study for application in flexible electronics field.Item A comparative study of fabrication of sand casting mold using additive manufacturing and conventional process(Springer, 2018-07) Hawaldar, Nishant; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and TechnologyIn this study, two processes to fabricate casting mold, conventional sand casting process and additive manufacturing or 3D printing process, are comparatively investigated. The two processes were compared in terms of their weight saving, surface finish, design allowance, and fettling work. The results show that there are significant advantages in using additive manufacturing in the production of mold. The 3D printed molds provide substantial saving of sand used, design allowances, and fettling work. The mechanical properties of 3D printed molds are also higher than the conventional ones due to good bonding strength during 3D printing.Item Correlation Between Process Parameters and Mechanical Properties in Parts Printed by the Fused Deposition Modeling Process(Springer, 2019) Attoye, Samuel; Malekipour, Ehsan; El-Mounayri, Hazim; Mechanical and Energy Engineering, School of Engineering and TechnologyFused deposition modeling (FDM) represents one of the most common techniques for rapid prototyping and industrial additive manufacturing (AM). Optimizing the process parameters which significantly impact the mechanical properties is critical to achieving the ultimate final part quality sought by industry today. This work investigates the effect of different process parameters including nozzle temperature, printing speed, and print orientation on Young’s modulus, yield strength, and ultimate strength of the final part for two types of filament, namely, Poly Lactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS). Design of Experiments (DOE) is used to determine optimized values of the process parameters for each type of filaments; also, a comparison is made between the mechanical properties of the parts fabricated with the two materials. The results show that Y-axis orientation presents the best mechanical properties in PLA while X-axis orientation is the best orientation to print parts with ABS.