Mechanical Engineering Commons^™

Microstructure Development Of Granular System During Compaction, Chen Shang, Marcial Gonzalez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Granular materials is the second most manipulated material in the industry today. They are easy to transport and more and more newly developed materials cannot stand the process of traditional casting, like energetic materials and bio-materials, but will survive the powder compaction process. Having a better understanding of the microstructure development of granular systems during compaction process, especially for particles that will heavily deform under loading, will give an insight of how to better process the powders to produce materials with overall better performance comparing to bulk materials. The main theory and mechanism applied are Hertz law and nonlocal contact …

Development Of Combined Dual-Pump Vibrational And Pure-Rotational Coherent Anti-Stokes Raman Scattering (Dpvcars And Prcars) System, Shenli Yuan, Aman Satija, Robert Lucht

The Summer Undergraduate Research Fellowship (SURF) Symposium

Coherent anti-Stokes Raman scattering (CARS) [1,2] is a spatially-resolved, time-resolved spectroscopic technique for quantitative measurements in reacting flows [3 – 6]. This work demonstrates a combination of N₂/O₂/CO₂ dual-pump vibrational coherent anti-Stokes Raman scattering (DPVCARS) system and two-beam pure-rotational coherent anti-Stokes Raman scattering (PRCARS) system. It is based on the previous development of combined VCARS and PRCARS system which was used to obtain temperature measurements in non-premixed H₂-air flames. The new combined system will be used to measure the temperature profiles and major species concentrations such as N₂/O₂/CO_{2 …}

Motion Control Of Robotic Arm With Command Shaping Method, Yumeng Wu, Peter H. Meckl, Alok Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the manufacturing industry, lots of rapid point-to-point motion is required while the residual vibration is unfavorable. Residual vibrations caused by flexible elements are limiting the performance of mechanical system, especially when the system needs to make rapid point-to-point motion. As proved in earlier studies, avoiding natural frequencies of the mechanical system reduces the residual vibrations. This work is based on a non-linear, two-link flexible jointed robot with configuration dependent resonance. Command shaping method consisting different combinations of base functions and weighting factors are compared in this work. The compatibility of command shaping with classical feedback control structure allows a …

Improved Microrobotic Control Through Image Processing And Automated Hardware Interfacing, Archit R. Aggarwal, Wuming Jing, David J. Cappelleri

The Summer Undergraduate Research Fellowship (SURF) Symposium

Untethered submilliliter-sized robots (microrobots) are showing potential use in different industrial, manufacturing and medical applications. A particular type of these microrobots, magnetic robots, have shown improved performance in power and control capabilities compared to the other thermal and electrostatic based robots. However, the magnetic robot designs have not been assessed in a robust manner to understand the degree of control in different environments and their application feasibility. This research project seeks to develop a custom control software interface to provide a holistic tool for researchers to evaluate the microrobotic performance through advance control features. The software deliverable involved two main …

Modeling Of Mixed Friction Interactions Occurring In Axial Piston Pumps, Andrew C. Adelsperger, Lizhi Shang, Dan Mizell, Monika Ivantysynova

The Summer Undergraduate Research Fellowship (SURF) Symposium

Axial piston pumps are integral to a variety of hydraulic systems due to their versatility and reliability, but most attempts to model them for design purposes have failed. However, software which fully models the fluid structures within these pumps, such as the FSTI gap design program, has improved significantly. Unfortunately, current discrepancies between simulated and measured friction forces on the cylinder due to the fluid drag and piston movement need to be eliminated so that more accurate simulation of these pumps in operation is possible. Friction measurements and FSTI simulation outputs were analyzed with MATLAB filters and graphs, resulting in …

Thermal Properties Of Soft Nanomaterials: Materials Synthesis And Fabrication, Meng Pan, Collier Miers, Amy Marconnet, Yu Han

The Summer Undergraduate Research Fellowship (SURF) Symposium

The properties of soft nanomaterials are hard to measure exactly due to their mechanical properties and unstable shape. In particular, hydrogels are a class of cross-linked polymers that can absorb large quantities of water changing their shape under the influence of various conditions such as humidity, temperature, and pH. This research addresses the fabrication of a material that has a significant contrast in properties under different conditions (e.g. temperature, wetting, and pH) and determine the physical mechanisms of heat transfer in this nanomaterial. The hydrogels are made using a several cycles of a freeze-thaw method. The method requires soluble material. …

Radiation Measurements And Data Analysis Of Turbulent Premixed Lean Flame, Yunzhe Yang, Dong Han, Jay P. Gore

The Summer Undergraduate Research Fellowship (SURF) Symposium

An accurate understanding of the radiation transfer in turbulent premixed lean flame is critical for improving energy efficiencies and reducing emissions such as nitric oxide and soot. Radiation measurement is an effective and nonintrusive way to study the radiation properties of turbulent premixed lean flames. In this study, a high-speed infrared camera was utilized to measure the planar radiation from turbulent premixed lean flames under different conditions. Time-dependent flame images were acquired and radiation statistics were calculated and compared to investigate the effects of equivalence ratio, heat release rate, hydrogen pilot flame rate, and co-flow rate on the radiation intensity …

The Role Of Surface Area In Catalytic Gasification Of Biomass, Elizabeth A. Wachs, Nitish Kumar, Indraneel Sircar, Prithviraja Basak, Jay P. Gore Phd

The Summer Undergraduate Research Fellowship (SURF) Symposium

Gasification of biomass has the potential to provide a carbon-negative source of liquid fuels. The current limited use of gasification is due in part to the high temperatures necessary to achieve high conversion levels. These temperatures can be lowered by the use of catalysts, but the mechanisms by which catalysts affect the reaction rate are not fully understood. Here, the structural component of potassium carbonate’s role in the gasification process was examined. Samples of pinewood sawdust were impregnated with potassium carbonate, then pyrolyzed with N2 in a fixed bed reactor at 750°C (heater thermocouple reading). Half of the char was …

Preliminary Testing Of Plasma-Induced Combustion, Ahmed Thalib Razi, Carson Slabaugh, Robert Lucht

The Summer Undergraduate Research Fellowship (SURF) Symposium

Plasma-induced combustion (PIC) has been shown to improve the reliability, efficiency, and delay time of ignition in flight systems like augmentors and scramjets. These high-velocity systems are mostly used in military applications, and improvement may help commercial viability. To understand this chemical process, the concentration of radicals, particularly H radicals, must be tracked through the flame using laser diagnostics. This requires a steady source of plasma-assisted combustion to be secured and well-understood. A plasma torch flowing partially premixed air and methane was installed and successfully operated, and preliminary testing was carried out. Primarily it was observed that PIC created stable …

Thermal Properties Of Soft Nanomaterials: Thermal Measurement Design, Yu Han, Meng Pan, Amy Marconnet, Collier Miers

The Summer Undergraduate Research Fellowship (SURF) Symposium

Soft materials like hydrogels have multiple tunable material properties because of their unique structures. Due to the ability to respond to stimuli like temperature or chemical environment, they have numerous applications in different fields like delivering drugs inside the human body and other medical uses. Details of the thermal transport mechanisms, as well as the overall thermal properties, are critical for a variety of applications. Multi-property measurements elucidate the underlying transport mechanisms in the soft materials. This research demonstrates a new methodology of measuring thermal properties of soft materials. This work uses the 3w method [1,2] for measuring the thermal …

Stereo Vision Based Hybrid Manufacturing Of Ti-6al-4v In Component Repair Process, Renwei Liu, Zhiyuang Wang, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Parts or products from high performance metal are very expensive, partly due to the processing complexities during manufacturing. Recent studies have indicated that hybrid processes of additive manufacturing and machining process can be used to repair titanium parts, thus extending the service life. In order to implement these methods automatically, it is necessary to obtain the spatial geometry information of component with defects to generate the tool path. The purpose of this paper is to summarize the research on hybrid manufacturing with stereo vision function which can be applied to the component repair process. Stereo vision is adopted to detect …

In Vitro Assessment Of Laser Sintered Bioactive Glass Scaffolds With Different Pore Geometries, Krishna C. R. Kolan, Albin Thomas, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The pore geometry of bioactive glass scaffolds intended for use in bone repair or replacement is one of the most important parameters that could determine the rate of bone regeneration. The pore geometry would also affect the mechanical properties of the scaffolds and their rate of degradation. Scaffolds with five different architectures, having ~50% porosity, were fabricated with silicate (13–93) and borate (13–93B3) based bioactive glasses using a laser sintering process. An established, late-osteoblasts/early-osteocytes cell line was used to perform cell proliferation tests on the scaffolds. The results indicated that the cells proliferate significantly more on the scaffolds which mimic …

Investigation Of Forged-Like Microstructure Produced By A Hybrid Manufacturing Process, Romy Francis, Joseph William Newkirk, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Metal Deposition (LMD) is an additive manufacturing technique for manufacturing complex near net shaped components. The grain size of the typical deposition microstructure in case of Ti-6Al-4V can range between 100µm-600µm, which is much larger than that of forged-like microstructures. Friction Stir Processing (FSP) has been investigated as a method for surface modification to form refined microstructure at the surface of the Ti-6Al-4V components manufactured from the LMD method. Integration of FSP and LMD can greatly improve the product properties. Friction stir processing of the laser deposited Ti-6Al-4V deposits was performed and optimum processing parameters were obtained using this …

Thermographic Investigation Of Laser Metal Deposition, Sreekar Karnati, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Primitive stages of studies on and with additive manufacturing techniques popularly involve thin wall geometry. In the current effort attempts were made to capture various thermal aspects during deposition of a thin wall geometry. The thermo-graphic data was captured using a FLIR A615 infrared camera. Post processing using edge detection algorithms and image processing techniques, the geometric and thermal aspects of meltpool and tail of the meltpool were obtained. The effect of geometry and power on shape of the meltpool and its tail were obtained. The depositions of SS 316 with varying power. These observations were discussed and analyzed in …

Investigation Of Sparse-Build Rapid Tooling By Fused Deposition Modeling, Osman Iyibilgin, Ming-Chuan Leu, Gregory Taylor, H. Li, K. Chandrashekhara

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper describes the investigation of sparse-build tooling by Fused Deposition Modeling (FDM®) aimed at rapid tooling with reduction in the amount of material. Sparse-build test coupons having ULTEM as the material and varying air gap (sparse spacing), wall thickness, and cap thickness were fabricated using the sparse and sparse-double dense build styles of the Stratasys Fortus machine. The strengths and moduli of these coupons were measured in compression and flexure tests. The strength/mass ratio and modulus/mass ratio were compared among the various coupons, as well as with solid coupons, to investigate the effects of the two build styles and …

A Mechanical Testing Methodology For Additive Manufacturing Processes, Sujitkumar Dongare, Todd E. Sparks, Joseph William Newkirk, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Most additive manufacturing processes are layer-by-layer deposition, thus its mechanical properties could be very different than those made from traditional manufacturing processes. This paper summarizes a mini-tensile testing methodology for additive manufacturing. Research concerning the tensile testing of metallic material has been conducted and test methods have been defined. It encompasses the methods for determination of yield strength, yield point elongation, tensile strength, elongation, and reduction of area. The study of positional variation and cooling-rate dependency in case of additive manufacturing proves to be expensive and time consuming with the full-size test specimens. Thus, this paper discussed a technique for …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Georgia Southern hosts prestigious National Science Foundation Research Experience for Undergraduates (REU) in Green- Engineered Transportation Technologies

Make Or Buy Analysis Model Based On Tolerance Design To Minimize Manufacturing Cost And Quality Loss, Cucuk Nur Rosyidi, Reza Rizkichani Akbar, Wakhid Ahmad Jauhari

Makara Journal of Technology

In a manufacturing company, manufacturing costs, or component prices, and tolerance will affect the price and the quality of a product. Companies must produce high-quality products with low manufacturing costs in order to keep their products competitive in the market; however, it is difficult to produce a high-quality product with a low manufacturing cost. Companies have difficulties in determining the components to be produced using their own manufacturing facilities (make) or outsourced to their suppliers (buy). Hence, a make or buy analysis is needed to minimize the manufacturing costs and quality loss and to determine the optimum alternative regarding make …

Observation Of Tunneling Effects In Lateral Nanowire Pn Junctions, Sri Purwiyanti, Arief Udhiarto, Daniel Moraru, Takeshi Mizuno, Djoko Hartanto, Michiharu Tabe

Makara Journal of Technology

As electronic device dimensions are continuously reduced, applied bias conditions significantly change and the transport mechanisms must be reconsidered. Tunneling devices are promising for scaled-down electronics because of expected high-speed operation and relatively low bias. In this work, we investigated the tunneling features in silicon-oninsulator lateral nanowire pn junction and pin junction devices. By controlling the substrate voltage, tunneling features can be observed in the electrical characteristics. We found that the minimum substrate voltage required for tunneling to occur in pn junctions is higher as compared with pin junctions. The main cause of these effects relies in the difference between …

Digestibility Of Betung Bamboo Fiber Following Fungal Pretreatment, Widya Fatriasari, Wasrin Syafii, Nyoman J. Wistara, Khaswar Syamsu, Bambang Prasetya

Makara Journal of Technology

This research evaluated the effect of fungal pretreatment of betung bamboo fibers and enzymatic- and microwaveassisted hydrolysis on the reducing sugar yield. The enzymatic hydrolysis of the pretreated biomass was carried out with cellulase and 10 and 20 FPU/g of substrate in a shaking incubator at 50 °C and 150 rpm for 48 h. The sulfuric acid concentration used in the microwave-assisted acid hydrolysis was 1.0, 2.5, and 5%, either with or without the addition of activated carbon. Microwave irradiation (330 Watt) was applied for 5–12.5 min. The yield of reducing sugar was better with the microwave-assisted acid hydrolysis, and …