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Full-Text Articles in Engineering

Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat Oct 2022

Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the effect of individual and combined additions of CaO-based expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) on key characteristics of flowable cement paste mixtures proportioned with a water-to-cement ratio of 0.40. Of special interest is the effectiveness of these admixtures to mitigate shrinkage of cementitious materials for 3D printing. Static and dynamic yield stress, plastic and apparent viscosities, and thixotropy were evaluated at 20-min intervals up to 90 min. Compressive strength development and autogenous shrinkage were also determined. A factorial design approach was developed to evaluate the synergetic effects of the shrinkage …


Thermal Post-Processing Of 3d Printed Polypropylene Parts For Vacuum Systems, Pierce Mayville, Aliaksei L. Petsiuk, Joshua M. Pearce Sep 2022

Thermal Post-Processing Of 3d Printed Polypropylene Parts For Vacuum Systems, Pierce Mayville, Aliaksei L. Petsiuk, Joshua M. Pearce

Michigan Tech Publications

Access to vacuum systems is limited because of economic costs. A rapidly growing approach to reduce the costs of scientific equipment is to combine open-source hardware methods with digital distributed manufacturing with 3D printers. Although high-end 3D printers can manufacture vacuum components, again, the cost of access to tooling is economically prohibitive. Low-cost material extrusion 3D printing with plastic overcomes the cost issue, but two problems arise when attempting to use plastic in or as part of vacuum systems: the outgassing of polymers and their sealing. To overcome these challenges, this study explores the potential of using post-processing heat treatments …


Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant Sep 2022

Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Extrusion-based 3D printing with rapidly hardening polymeric materials is capable of building almost any conceivable structure. However, concrete, one of the most widely used materials for large-scale structural components, is generally based on inorganic binder materials like Portland cement. Unlike polymeric materials, a lack of precise control of the extent and rate of solidification of cement-based suspensions is a major issue that affects the ability to 3D-print geometrically complex structures. Here, we demonstrate a novel method for controllable-rapid solidification of concentrated mineral suspensions that contain a polymer binder system based on epoxy and thiol precursors as well as one or …


Waste Plastic Direct Extrusion Hangprinter, Aliaksei Petsiuk, Bharath Lavu, Rachel Dick, Joshua M. Pearce Aug 2022

Waste Plastic Direct Extrusion Hangprinter, Aliaksei Petsiuk, Bharath Lavu, Rachel Dick, Joshua M. Pearce

Michigan Tech Publications

As the additive manufacturing industry grows, it is compounding the global plastic waste problem. Distributed recycling and additive manufacturing (DRAM) offers an economic solution to this challenge, but it has been relegated to either small-volume 3D printers (limiting waste recycling throughput) or expensive industrial machines (limiting accessibility and lateral scaling). To overcome these challenges, this paper provides proof-of-concept for a novel, open-source hybrid 3D printer that combines a low-cost hanging printer design with a compression-screw-based end-effector that allows for the direct extrusion of recycled plastic waste in large expandable printing volumes. Mechanical testing of the resultant prints from 100% waste …


Process Evaluation And Kinetic Analysis Of 3d-Printed Monoliths Comprised Of Cao And Cr/H-Zsm-5 In Combined Co2 Capture-C2h6 Oxidative Dehydrogenation To C2h4, Khaled Baamran, Shane Lawson, Ali A. Rownaghi, Fateme Rezaei May 2022

Process Evaluation And Kinetic Analysis Of 3d-Printed Monoliths Comprised Of Cao And Cr/H-Zsm-5 In Combined Co2 Capture-C2h6 Oxidative Dehydrogenation To C2h4, Khaled Baamran, Shane Lawson, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study, dual-function materials (DFMs) comprised of CaO and Cr/H-ZSM-5 were formulated in 3D-printed monolithic structures and investigated in a combined process for capture and utilization of CO2 in oxidative dehydrogenation of C2H6 to C2H4 (CO2-ODHE). Various formulation strategies were employed to fabricate these DFM structures. Two bed designs were considered: i) a layered-bed in which adsorbent (CaO) and catalyst were printed separately and stacked on top of each other, and ii) a single-layer bed where the adsorbent-catalyst materials were 3D-printed into a singular monolith and loaded into the bed …


Integrated Direct Air Capture And Oxidative Dehydrogenation Of Propane With Co2 At Isothermal Conditions, Shane Lawson, Khaled Baamran, Kyle Newport, Turki Alghamadi, Gary Jacobs, Fateme Rezaei, Ali A. Rownaghi Apr 2022

Integrated Direct Air Capture And Oxidative Dehydrogenation Of Propane With Co2 At Isothermal Conditions, Shane Lawson, Khaled Baamran, Kyle Newport, Turki Alghamadi, Gary Jacobs, Fateme Rezaei, Ali A. Rownaghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Developing routes of utilizing CO2 emissions is important for long-term environmental preservation, as storing such emissions underground will eventually become unsustainable. One way of utilizing CO2 emissions is as a light-oxidant feedstock for oxidative dehydrogenation of propane (ODHP) to propylene. However, the adsorption and reaction steps typically occur at widely different temperatures, meaning that the thermal gradients – and by extension process energy requirements – are often unreasonably high. In recent years, dual-functional materials (DFMs) – i.e., materials comprised of a high temperature adsorbent phase alongside a heterogeneous catalyst – have been employed for combined CO2 adsorption …


Design Of Broadband Helmholtz Resonator Arrays Using The Radiation Impedance Method, Vidhya Rajendran, Andy Piacsek, Tomás Méndez Echenagucia Jan 2022

Design Of Broadband Helmholtz Resonator Arrays Using The Radiation Impedance Method, Vidhya Rajendran, Andy Piacsek, Tomás Méndez Echenagucia

All Faculty Scholarship for the College of the Sciences

This paper describes the design process of a low-frequency sound absorptive panel composed of differently tuned Helmholtz resonators (HRs), considering size and fabrication constraints relevant for applications in the building sector. The paper focuses on cylindrical and spiral resonators with embedded necks that are thin and can achieve high absorption. the mutual interaction between the resonators was modeled based on the radiation impedance method and it plays a key component in enhancing the absorption performance of the array. The differential evolution search algorithm was used to design the resonators and modify their mutual interaction to derive the absorption performance of …


Reducing Print Time While Minimizing Loss In Mechanical Properties In Consumer Fdm Parts, Long Le, Mitchel A. Rabsatt, Hamid Eisazadeh, Mona Torabizadeh Jan 2022

Reducing Print Time While Minimizing Loss In Mechanical Properties In Consumer Fdm Parts, Long Le, Mitchel A. Rabsatt, Hamid Eisazadeh, Mona Torabizadeh

Mechanical & Aerospace Engineering Faculty Publications

Fused deposition modeling (FDM), one of various additive manufacturing (AM) technologies, offers a useful and accessible tool for prototyping and manufacturing small volume functional parts. Polylactic acid (PLA) is among the commonly used materials for this process. This study explores the mechanical properties and print time of additively manufactured PLA with consideration to various process parameters. The objective of this study is to optimize the process parameters for the fastest print time possible while minimizing the loss in ultimate strength. Design of experiments (DOE) was employed using a split-plot design with five factors. Analysis of variance (ANOVA) was employed to …