Mechanical Engineering Commons^™

Mems 411: St. Louis Science Center Vibration Station, Allie Periman, Hailey Hayes, Brian Higgins

Mechanical Engineering Design Project Class

Student groups work on an open-ended mechanical design problem and finish the semester with a physical prototype, a design report, and a presentation delivered to an external review board. Groups are guided through the engineering design process by completing a set of project deliverables. The quality of these deliverables provides a basis for the evaluation of individual and team performance. This course emphasizes the importance of user-centric design, communication and presentation skill, consideration of real-world constraints, sketching and creativity, prototyping, and data-driven decision-making using engineering models and analyses.

Prediction Of Residual Stress And Distortion In Laser Powder Bed Fusion Additive Manufacturing, Bhanuprakash Sairam Kosaraju

Theses and Dissertations

Additive Manufacturing (AM) has its proven advantages to unlock the design space and manufacturing capabilities for complex geometries with lightweights. Distortion is one of the most common defects that occur in Laser Powder Bed Fusion Additive Manufacturing (LPBFAM), which is caused by the significant residual stress during the printing process. This can lead to numerous process iterations to achieve the requisite form and fit tolerances.

In this study, Finite Element (FE) model that utilizes the element birth approach was developed to predict the residual stress and distortion in the LPBFAM process. The methodology leverages a simplified approach where the detailed …

Anisotropic Wave Behavior In Isotropic Material With Orthogonal Surface Perturbation, Khaleda Akter

Theses and Dissertations

Elastic wave propagation in anisotropic media is of great interest in various branches of engineering and applied sciences. In this study, an anisotropic wave propagation behavior in isotropic material with orthogonal surface perturbation is presented. The conventional method of estimating dispersion equations for isotropic material is to apply Helmholtz decomposition on the potential functions for Rayleigh-Lamb wave and Shear Horizontal (SH) waves. However, the presence of isotropic material with orthogonal surface perturbations in two coordinate directions significantly affect the wave propagation behavior due to its direction dependency, and hence, the Helmholtz decomposition of the potential functions cannot be applied to …

Experimental Study Of Hollow-Core Slab Containing Waste Pet Bottles, Mulia Orientilize, Josia Irwan Rastandi, R. M. Dimas Aries C., Marsha Niken P., Krisna Adi S.S., Abimantrana Abimantrana

Makara Journal of Technology

This study investigated the utilization of plastic-waste concrete as an effort to reduce urban waste problems. The waste plastic bottles were utilized to form the hollows of the hollow-core slabs (HCSs). The bottles were made of polyethylene terephthalate (PET). As a part of green research to reuse waste material, shredded PET was also added to the concrete mixture to improve the HCS strength. The cast-in-site HCS could be constructed without any difficulties. Three parameters were investigated: the effects of void content, shredded PET content, and steel-fiber (SF) content on the HCS ultimate bending capacity (Mu). Fifteen specimens were tested under …

Oxidation Polymerization Additive Manufacturing, Jonghyun Park, Tazdik Patwary Plateau, Hiep Pham

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Various processes for producing three dimensional electrically conductive polymer structures, such as three dimensional structures of poly(3,4-ethylenedioxythiophene), are described as well as materials produced by these processes.

Preferential Vaporization Potential Of Crude Oils And Its Impact On Flame Flashback Behaviors, Ayuob Al Wahaibi

Theses and Dissertations

As combined cycle gas turbines for power generation operating on light distillate fuels provide a sufficient energy, there is a global trend in using heavy liquids (e.g. HFO, crude oils) for direct-firing in gas turbine. However, using these heavy fuels imposes many challenges due to their wide range of physical/chemical properties, which control near-limit combustion behaviors, such lean blow-out and flashback. In addition, the ignition propensity of these heavy fuels is not reported in crude assays, and utilizing a simple, with small sample, and quick methodology to characterize the ignition propensity is important in determining the fuel quality.

In this …

Anisotropic Scaffolds For Peripheral Nerve And Spinal Cord Regeneration, Wen Xue, Wen Shi, Yunfan Kong, Mitchell Kuss, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

The treatment of long-gap (>10 mm) peripheral nerve injury (PNI) and spinal cord injury (SCI) remains a continuous challenge due to limited native tissue regeneration capabilities. The current clinical strategy of using autografts for PNI suffers from a source shortage, while the pharmacological treatment for SCI presents dissatisfactory results. Tissue engineering, as an alternative, is a promising approach for regenerating peripheral nerves and spinal cords. Through providing a beneficial environment, a scaffold is the primary element in tissue engineering. In particular, scaffolds with anisotropic structures resembling the native extracellular matrix (ECM) can effectively guide neural outgrowth and reconnection. In …

Soft Robot Locomotion Via Mechanical Metamaterials: Application In Pipe Inspection, John Barr, Andrew Boyle, Matthew Goodfellow, Nick Rogers, Caroline Stephens

Mechanical Engineering Senior Theses

Pipe inspections are performed using large robots that utilize wheels or tracks for locomotion. Due to their large size, weight and hard exterior, these robots can occasionally cause damage to the pipe interiors during inspection. In addition, these pipe inspection robots struggle with the ability to move in a congested environment and adapt to obstacles or geometry changes within the pipe. This project investigates the capabilities of auxetic and conventional metamaterials to achieve locomotion in an enclosed channel through the different metamaterials reactions to an axial force. The resulting robot is capable of both horizontal and vertical locomotion. Computer simulation …

Generating Rock Volumes Of Lower Radii (Grvlr) - Rock Crusher, Samuel Broyles, James Forman, Karla Raigoza, Hailee Silva

Mechanical Engineering Senior Theses

The GRVLR team designed and constructed a human powered rock crusher intended to assist impoverished widows in Birendranagar, Nepal. These women crush rocks for a living as a result of intense gender discrmination which limits their access to better employment opportunities. The goal of this device was to provide an alternative method to this work that was superior under the criteria of efficiency, ergonomics, and safety. In order to inform the design of the machine, the GRVLR team used customer needs data to generate design requirements and success metrics, and finite element analysis (FEA) in order to evaluate and improve …

Improving The Intellectual And Social Development Of Children With Autism: Design Of A Training Center For Autism, Hasti Jalalian

Makara Journal of Technology

Research on the relationship between the role of architecture and the psychology of children with autism, which indicates that appropriate environments for these children can have a significant effect on their healthcare process, has been recently conducted. However, statistics show that autism spectrum disorders are pervasive, and its extent in Iran has been increasing. Moreover, centers that are specifically designed for children with autism are limited, and paradigms are made without considering the mood of these children. Given the role of architecture in designing a suitable space for these children, an investigation that can identify the specific requirements of these …

Numerical Study Of A Buckling Restrained Brace (Brb) In Steel Structures And Comparison With A Convergent Ordinary Brace (Ocb) Under Static And Dynamic Loading, Fatemeh Habibpour

Makara Journal of Technology

Bulk metallic glass (BMG) has good mechanical strength, high hardness, wear resistance, and corrosion resistance with promising application in various industries. However, for the industrial production of BMG, the main issue is how to overcome limitations of joining with other materials. The present study focuses on solder processing at low operating temperature to avoid exceeding the recrystallization temperature. A feasible joining process for BMG was developed using lead-free solders. The BMG surface is pre-plated with copper, nickel, or titanium as a wetting layer. The reaction temperature is set between the glass transition temperature of BMG and the melting point of …

Spike Nozzle Design For Use In Nanosat Orbital Maneuvering, Drew Nemeth

Undergraduate Research Symposium Podium Presentations

Annular spike nozzle engines have long been the holy grail of rocket engine design, promising superior performance in a smaller footprint when compared to conventional bell nozzles. However, flaws inherent to the design of spike nozzles have prevented widespread adoption and testing. As a result, research on potential applications has been quite sparse. This project aims to further spike nozzle research by investigating rarely tested materials that literature suggests have potential for use in a spike nozzle design. The goal of the overall research project is to examine 3D printed polycarbonate component longevity under conditions representative of a small satellite …

Toward The Use Of Drones For Photovoltaic Panel Inspection, Fausto Vega

Undergraduate Research Symposium Posters

The monitoring of photovoltaic panels is an essential task to maintain the efficiency of the power plant. The conventional form of inspection consists of manual inspection with a thermal camera which takes several days as fields contain thousands of panels. Solar panel installation is costly, and the installation does not guarantee maximum power generation without proper maintenance and handling. A drone with a thermal camera payload was developed to reduce labor costs as well as increase efficiency of the inspection as it can survey the field with a large field of view. Several image processing methods were used to process …

Analysis Of The Interfacial Reaction Between Bulk Metallic Glass Coated Copper, Nickel, And Titanium With Lead-Free Solders, Andromeda Dwi Laksono, Yee-Wen Yen, Rifqi Aulia Tanjung, Teodoro A. Amatosa, Ruki Harwahyu

Makara Journal of Technology

Bulk metallic glass (BMG) has good mechanical strength, high hardness, wear resistance, and corrosion resistance with promising application in various industries. However, for the industrial production of BMG, the main issue is how to overcome limitations of joining with other materials. The present study focuses on solder processing at low operating temperature to avoid exceeding the recrystallization temperature. A feasible joining process for BMG was developed using lead-free solders. The BMG surface is pre-plated with copper, nickel, or titanium as a wetting layer. The reaction temperature is set between the glass transition temperature of BMG and the melting point of …

Design Of Ac Microgrid Topology With Photovoltaic Uncertainties In A Rural Village, Vannak Vai

Makara Journal of Technology

Energy needs are increasing day by day, especially for developing countries, due to population growth and changing lifestyles. A suitable microgrid topology with renewable energy integration is considered to fulfill the people and society’s needs. This paper focuses on the design of AC microgrid topology for a nonelectrified village with the integration of PV uncertainties in both sitting and sizing. The development of an optimal algorithm based on the conductor use minimization and unbalanced load improvement is proposed. The shortest path is proposed to search for the minimum conductor use. Then, the algorithm for improving the unbalanced load with two …

Mean-Shift Object Tracking Algorithm With Systematic Sampling Technique, Yoanes Bandung, Aris Ardiansyah

Makara Journal of Technology

Mean shift is a fast object tracking algorithm that only considers pixels in an object area, hence its relatively small computational load. This algorithm is suitable for use in real-time conditions in terms of execution time. The use of histograms causes this algorithm to be relatively resistant to rotation and changes in object size. However, its resistance to lighting changes is not optimal. This study aims to improve the performance of the algorithm under lighting changes and reduce its processing time. The proposed technique involves the use of sampling techniques to reduce the number of iterations, optimization of candidate search …

Analysis Of Correlation And Mapping Of Chlorophyll-A Concentrations And Sea Surface Temperatures In Coastal Areas Based On Terra Modis Satellite Image Data, Hendrata Wibisana, Bangun Muljo Sukotjo, Umboro Lasminto

Makara Journal of Technology

Ecosystems in aquatic environments are distinct from ecosystems on land. Changes that occur in ecosystems in aquatic environments affect the lives of biota in these waters, including the fish used as a food source in fishing communities in coastal areas. This study aims to determine the role of remote sensing in mapping and analyzing the relationship between the parameters of sea surface temperature and chlorophyll-a concentrations on the coast. The correlation of sea surface temperature with chlorophyll-a concentrations is modeled via linear regression. An analysis of variance test is performed to establish the suitability of the temperature data for the …

A Comparative Study Between 6 Degree-Of-Freedom Trajectory Model And Modified Point Mass Trajectory Model Of Spinning Projectiles, Ange Du

Doctoral Dissertations and Master's Theses

For spinning projectiles, the 6 Degree-of-Freedom model can closely capture their trajectories with high accuracy and details. However, it comes with the drawbacks of long computation time and needing many aerodynamic coefficients which can be hard to obtain. The Modified Point Mass Trajectory Model was introduced as a simplified solution. This work compares them with each other, and with some more conventional methods. A program is developed to simulate and visualize trajectories. With some augmentations, the Modified Point Mass model is able to generate comparable results in most cases, but not including special cases such as when the projectile is …

Lean Implementation In An Aquatic Cryopreservation Laboratory, Jennafer Zimmerman

Honors Capstones

No abstract provided.

Mems 411: Dressmaker Pin Dispenser, Alex Goertz, Henry Holtz, Seamus Boyle, Youngjin Hong

Mechanical Engineering Design Project Class

The goal of this project was to design, manufacture, and test a machine which can dispense dressmaker pins in a consistent orientation, allowing the user can easily, and safely remove them one at a time. The purpose of the machine is to increase the efficiency and safety of sewers who may use dressmaker pins daily.

Mems 411: Lost Grains Winnower, Seth Jack, Matthew Finer, Alex Maggioni, Kristian Nilsen

Mechanical Engineering Design Project Class

This project involved designing an upgrade for the grain winnower in Dr. Mueller’s anthropology lab at Washington University in St. Louis. A winnower is a device that separates chaff from usable grain after harvesting and threshing. Many such devices exist, from industrial-scale winnowers sorting high volumes of grain to personal coffee bean winnowers. However, the constraints of the lab space and the specialized nature of the grain being winnowed presented specific constraints. An interview with Dr. Mueller was necessary to determine a ranked list of needs for use in the final product. After creating these rankings, a mock-up was used …

Instrumentation And Experimentation Development For Robotic Systems, Tristan Kyzer

Theses and Dissertations

Localization of robotic systems is a necessity for control of robotic systems and often requires the use of costly sensors and equipment onboard the robot or installed within a facility. GPS or GNSS sensors are effective for localizing robots in GPSaccessible environments, but do not work as well in dense urban areas or inside fully enclosed buildings, such as factories or warehouses. Sensors such as LiDAR can be costly and require substantial experience and knowledge to utilize as well as potential changes to infrastructure for use. Computer vision-based localization systems offer potential as a localization solution for various applications. A …

Nondestructive Evaluation And Structural Health Monitoring Of Manufacturing Flaws And Operational Damage In Composite Structures, Robin James

Theses and Dissertations

Advanced composite materials have begun to be used extensively in the manufacturing of aerospace structures. Composite aerospace structures can develop complex types of damages during the manufacturing stages and operational lifetime. This creates an indispensable demand for appropriate nondestructive evaluation (NDE) and structural health monitoring (SHM) methods that are tailored to specific types of damage. This dissertation addresses innovative methods for NDE and SHM of manufacturing flaws and operational damage in composite structures.

For the NDE of manufacturing flaws in carbon fiber reinforced polymer (CFRP) composites, an eddy current testing (ECT) NDE method has been developed by conducting multiphysics modeling …

Experimental Investigation Of Single And Two-Phase Heat Transfer Performance In Microchannels With Surface Modifications And Multiple Inlet Restrictors, Saad Kadham Oudah

Theses and Dissertations

Due to shrinking component sizes and faster switching speeds, the volumetric heat generation rates and surface heat flux in many advanced power electronic devices have increased exponentially, creating an urgent need for efficient cooling technologies. It has become particularly challenging to maintain an optimal temperature at the device level. Among advanced cooling techniques, single-phase and two-phase microchannel heat sinks show considerable promise in removing a significant amount of heat from a small surface area. Considered one of the most efficient heat dissipaters, the two-phase microchannel heat sink can handle very high heat flux at a small footprint and requires relatively …

Multimodal Robotic Health In Future Factories Through Iiot, Data Analytics, And Virtual Commissioning, Clint Saidy

Theses and Dissertations

The manufacturing sector is continuously reinventing itself by embracing opportunities offered by the industrial internet of things and big data, among other advances. Modern manufacturing platforms are defined by the quest for ever increasing automation along all aspects of the production cycle. Furthermore, in the next decades, research and industry are expected to develop a large variety of autonomous robots for a large variety of tasks and environments enabling future factories. This continuing pressure towards automation dictates that emergent technologies are leveraged in a manner that suits this purpose. These challenges can be addressed through the advanced methods such as …

Enhanced Flow Boiling And Bubble Dynamics With Hfe7100 & Di Water In Interconnected Microchannels, Jiaxuan Ma

Theses and Dissertations

Flow boiling in microchannels using dielectric fluids is one of the most desirable cooling solutions for high power electronics. Primary two-flow patterns, including bubbly flow, slug flow, and annular flow, have been well established in microchannels. However, it is challenging to promote flow boiling performance, particularly critical heat flux (CHF), due to their unfavorable thermophysical properties. Considering these situations, flow boiling in parallel and isolated microchannels have been extensively studied. In this dissertation, a novel concept that has five parallel microchannels (W=200 µm, H=250 µm, L=10 mm) are interconnected by micro-slots (20 µm wide and 250 µm deep) starting from …

Gradient-Based Tradeoff Design For Engineering Applications, Lena Alexis Royster

Mechanical & Aerospace Engineering Theses & Dissertations

This research presents a formal method for gradient based tradeoff design including methods that extend to cases with singularities and cases with more performance characteristics then design variables. The goal is to find revised design variables that can achieve the targeted performance characteristics and remove any violations to the constraint functions. The tradeoff design problem is formulation in the framework of the Sequential Quadratic Programming and is solved using the gradient based method. The optimal solution is the search direction, s, which represents the most effective way to reduce the current objective and correct the current violation. In this research …

Grafting Based Thermoplastic-Thermoset Bonding For Aerospace Structures, Saurabh Vaidya

Theses and Dissertations

The use of carbon fiber composites is rapidly increasing in the aerospace industry. Fiber reinforced plastic composites can primarily be classified as thermoplastic and thermoset, both offer unique advantages over one another. Thermosets cure at relatively low temperature and in general, are lower priced than thermoplastic composites. However, the cost of autoclave for the curing of thermosets is a major drawback. On the other hand, thermoplastics are showing higher damage tolerance. They can be re-melted and re-consolidated and have the potential to be re-used / recycled. The repair of TP composites is not developed yet. Therefore, both the types attract …

An Acoustic Emission And Artificial Intelligence Approach To Structural Health Monitoring For Aerospace Application, Joseph Chandler Garrett

Theses and Dissertations

In the area of aerospace and other applications, structural health monitoring (SHM) has been a significant and growing area of research in recent years. Throughout the operational life of aerospace structures, various damage scenarios may manifest, and it is of great concern to the aerospace community to develop methodologies for detecting and assessing these damage scenarios. In this paper, fundamental research on the use of the acoustic emission (AE) approach to SHM for fatigue crack growth is presented. In general, the AE approach to SHM and non-destructive evaluation (NDE) involves the sensing of ultrasonic Lamb waves propagating through a structure. …

Separate Effects Tests For Studying Thermal Gradient Driven Cracking In Uo2 Pellets Undergoing Resistive Heating, Sobhan Patnaik

Theses and Dissertations

A variety of normal operation and accident scenarios can generate thermal stresses large enough to cause cracking in light-water reactor (LWR) fuel pellets. Cracking of fuel pellets can lead to reduced heat removal, larger centerline temperatures, and localized stress in cladding, all of which impact fuel performance. It is important to understand the temperature profile on the pellet before and after cracking to improve cracking models in fuel performance codes such as BISON. However, in reactor observation and measurement of cracking is very challenging owing to the harsh environment and design of fuel rods.

Recently, a state-of-the-art experimental pellet cracking …