Materials Science and Engineering Commons^™

Effect Of Expanded Perlite And Exfoliated Vermiculite Aggregate Additives On Water Vapor Permeability Performance Of Cement-Based Lightweight Mortars, Lütfullah Gündüz, Şevket Onur Kalkan

Journal of Sustainable Construction Materials and Technologies

Vapor diffusion is the movement of water vapor molecules through porous materials such as wood, insulation products, and lightweight wall elements due to differences in vapor pressure. Vapor retarders are used to control vapor diffusion through wall sections and surfaces. All building materials provide some resistance to vapor diffusion, and the amount of resistance varies depending on the material's properties. These properties can vary with relative humidity and moisture content, age, temperature, and other factors. Vapor resistance is usually expressed using the inverse term of ``vapor permeability,'' which is the relative ease of vapor diffusion through a material. Water vapor …

Rubber-Modified Self-Compacting Mortar: Evaluating Setting Time And Strength Development, Navvar Makansi, Süleyman Ipek, Erhan Güneyisi

Journal of Sustainable Construction Materials and Technologies

The influence of using crumb rubber (CR) obtained from the second scraping of used tires as fine aggregate in manufacturing self-compacting mortar (SCM) was investigated experimentally in this study. To explore this, natural fine aggregate in SCM mixes was partially replaced with CR at levels ranging from 5% to 25% by total fine aggregate volume. Two mix series, one with a total binder of 500 kg/m3 and the other with a 540 kg/m3 binder, were designed at water-to-binder ratios of 0.40 and 0.33. Ordinary Portland cement (80% by weight) and fly ash (20% by weight) were used to manufacture mortars. …

Smart Traffic Management At Intersections, Gezim Hoxha, Piotr Gorzelanczyk, Rame Likaj, Shaban Thaqi, Flori Cikaqi

Journal of Sustainable Construction Materials and Technologies

Effective traffic control methods, whether at intersections or other nodes within the road network, play a critical role in ensuring traffic quality and safety. An inappropriate choice of traffic control techniques or poorly optimized light signal programming at intersections often leads to unsatisfactory service levels. This study specifically addresses the issues related to intersections controlled by traffic lights. It aims to identify the key factors influencing the regulation and programming of traffic lights, with a focus on using different microcontrollers, particularly the Raspberry Pi. The primary objective of this research is to develop a methodology and an adapted programming approach …

Identification Of Barriers And Drivers In The Adoption Of Sustainable Construction Practices In The Turkish Construction Industry: Exploratory Factor Analysis, Tülay Çivici, Mustafa Serhan Ünlütürk

Journal of Sustainable Construction Materials and Technologies

Although the importance of sustainability in the construction industry has been emphasised by many researchers and endorsed by many authorities, it is clear that the practices in the industry still need to be improved. The primary issue for adopting sustainable practices in the construction industry is identifying the barriers and drivers. For this reason, the study analysed the literature to identify the critical barriers and incentives for adopting sustainable practices in the construction industry. In light of the information from the literature, the necessary barriers and motivators in adopting sustainable practices in the construction industry were determined, and a questionnaire …

Synergistic Effect Of Alccofine As Partial Replacement Of Cement And M-Sand As Sand Substitution In Concrete For The Assessment Of Mechanical And Microstructural Properties, Yellinedi Madhavi, R.S. Ravichandran, J. Saravanan, N. Venkatasairam Kumar

Journal of Sustainable Construction Materials and Technologies

Using supplementary cementitious materials (SCMs) and traditional binder mass has revolutionized concrete production technology in the building industry. This study examines how Alcofine-1203 affects the microstructure and mechanical characteristics of concrete. The mechanical qualities of the mixtures were evaluated using six different mixes prepared for each M25 and M40 Grade. In the proposed mixes, cement is substituted with alccofine at 0 to 25% and M-Sand as fine aggregate. The Compressive strength and ultrasonic pulse velocity were assessed after 3, 7, 14, 28, 56, and 90 days of curing, and split tensile strength and flexure strength were evaluated after 28 and …

Sustainable Modification Of Stone Column Technique With Polyethylene Terephthalate (Pet) Plastic For Strengthening The Expansive Clay, Ng Jun Shen, Muzamir Hasan

Journal of Sustainable Construction Materials and Technologies

This research investigated the modification of stone column application by the association of PET plastic as a coarse aggregate material for sustainable material replacement. Clay soil improvement with a granular material fabricated column substantially affected its soil-bearing capacity. Subsequently, it avoided severe problems such as soil settlement and structural instability. Previous studies have mentioned the function and alteration of stone columns using materials like bottom ash and fly ash. Still, no attention has been paid to the utilization of PET plastic for this area. This study examined the feasibility and reliability of materials, PET plastic, and kaolin clay S300 before …

Effect Of Reinforcement Thickness And Content On The Properties Of Compressed Earth Blocks, Salah Eddine Mokeddem, Abdelmadjid Hamouine, Rabia Abdeldjebar, Atef Hamaidi

Journal of Sustainable Construction Materials and Technologies

This study explores the mechanical, hygroscopic, and thermal behavior of stabilized and unstabilized compressed earth blocks (CEB) by incorporating date palm wood chips (DPWC) as a natural fiber additive. The investigation covers a range of DPWC thicknesses (1 mm, 2 mm, 3 mm) and content variations (0% to 1% by weight), focusing on the interaction between the bio-based reinforcement and the stabilized soil matrix, which is stabilized with 10% white Portland cement. The mixtures were compressed at a pressure of 5 MPa using a hydraulic press, providing a detailed examination of how these parameters impact the structural integrity and functional …

Utilization Of Rubber Tire Composition For The Mechanical And Dynamic Performance Of An Energy Dissipation Damper, Ahmed Sami Hasan Al-Osta

Student Works (2020-2029)

Economic development results in a rise in the demand for different items, such as rubber products. Consequently, there is a continuous growth in the amount of waste rubber products generated globally each year. The waste generated from solid tires, composed of non-biodegradable substances, poses significant environmental and public health concerns. Protecting critical buildings, bridges, potentially hazardous industrial operations, and valuable equipment against earthquakes is crucial for ensuring safety and minimizing economic losses. This study aims to evaluate rubber tires' damping mechanical and dynamic properties by optimizing the rubber tire composition. Various rubber compositions were examined to determine the most efficient …

Model-Based Design Of Compressed Lithium-Metal Pouch Cell Battery Modules For Evtol Applications, Scott J. Stirling

Master's Theses

Batteries with higher specific energy and power are essential for extending the range and performance of electric vertical takeoff and landing aircraft (eVTOLs). Anode-free lithium-metal pouch cells offer strong potential at the cell-level but require high compressive pressures to enhance cycle life and discharge performance. These pressures necessitate heavier structural components, reducing packaging efficiency at the module level.

To evaluate this tradeoff, a full-factorial enumeration model was developed to explore viable module designs within a constrained packaging volume. The model scales subsystem masses, enforces design rules and material limits, and accounts for large (~20%) cell thickness changes during cycling.

Results …

In-Situ Defect Detection In Selective Laser Melting Using Convolutional Neural Networks, Ethan Gaigalas

Master's Theses

This thesis develops and trains a convolutional neural network (CNN) to classify defects in metal parts produced by selective laser melting (SLM) using acoustic emission (AE) data. The model successfully identified porosity and standard build layers with high accuracy but consistently struggled to classify lack of fusion (LOF) defects, regardless of input type, normalization, or class count. These results suggest that while AE signals contain distinguishable features for certain defect types, LOF signals may be too subtle or inconsistent for reliable detection. The study addresses the ongoing challenge of in-situ quality monitoring in metal additive manufacturing, where defects like cracks, …

Effect Of Manufacturing And Machining Process On Recycled Composite Connecting Rods Under Tension And Compression, Walter W. Oppelt

Master's Theses

Carbon fiber reinforced polymer (CFRP) is an engineering material renowned for its high-strength and low-density material properties. Such properties make CFRPs especially useful for applications across many industries, including aerospace, automotive, marine, sporting goods, oil and gas, and more. However, with such favorable material properties comes the cost of high energy usage required to produce raw carbon fiber. Recycled carbon fiber (rCF) has emerged as a promising alternative, offering a significant reduction in energy usage. This research explores the viability of applying recycled CFRPs to internal combustion engines to both reduce energy costs during manufacturing and while in use. Mechanical …

Thermal Modeling Techniques For Additively Manufactured Porous Metals, Lucas D. Rambo

Master's Theses

Advances in additive manufacturing have enabled the creation of metallic components with tailored porosity, offering design flexibility for thermal, structural, and fluid transport applications. This thesis investigates the effective thermal conductivity (ETC) of porous Inconel 625 (IN625) and Inconel-ceramic composites (IN625-RAM2) fabricated by Laser Powder Bed Fusion (LPBF) using Elementum 3D’s PermiAM technology. Experimental measurements of thermal conductivity using the laser flash method are compared to numerical models built from micro-computed tomography data. Simulations were performed using both finite element (FE) and finite volume (FV) methods to evaluate thermal transport in real microstructures. The study investigates the effects of micro- …

Multimodal Self-Folding Of Shape Memory Polymer Using Laser Induced Graphene, Liam Harrison Drew

Master's Theses

Shape memory polymers (SMPs) can undergo programmed shape transformations when heated above their glass transition temperature (T_g), enabling actuation through stimuli such as infrared (IR) radiation and Joule heating. These materials are promising for deployable systems and soft robotics due to their lightweight structure and elimination of traditional mechanical components. While IR-based actuation is simple and low-cost, it lacks precision in uncontrolled environments. Joule heating offers improved control but is often limited by conductive ink properties such as thickness, stiffness, or poor adhesion. This work introduces a novel method for multimodal SMP actuation using laser-induced graphene (LIG) transferred …

Comparative Study Of Experimental And Fea Strain Data For Cnt-Coated Fiberglass Sensors, Extensometers, And Metal Foil Strain Gauges, Omar Dwidar

Master's Theses

Material testing is essential across industries such as aerospace, automotive, and construction, playing a critical role in verifying material selection, diagnosing failures, and understanding the development of flaws in structures. These insights are key to designing successful, reliable systems. Conventional metal foil strain gauges are low cost and reliable but provide limited sensitivity with a typical gauge factor around 2. Extensometers provide highly sensitive strain measurements with the disadvantage of a bulky form factor. With advanced materials such as carbon nanotubes, it is possible to manufacture a sensor with the sensitivity closer to that of an extensometer with the small …

3d Printed Fixed Wing Aircraft Competition, Sidney E. Long, Mitchell Heise, Jack Bride, Daniel Salinas

Mechanical Engineering

Cal State LA and Arlington University, Texas are hosting the same 3D printed, fixed wing aircraft competition for 2025. Cal Poly requires a competitive plane that can adhere to each rule and be piloted remotely to achieve the longest time in the air. The plane must utilize solely 3D printing technology for the wings, body, and all other structures. The only off-the-shelf components can be the motor and electronics, as well as mechanical devices such as hinges.

Design Principles For Robotic-Controlled 3d Printing Of Soft Tissue-Mimicking Materials, Karina Mealey

Master's Theses

Geometrically and physically accurate 3D models are emerging as essential tools for surgeons in pre-operative planning and training, but current methods of producing these models are not sufficient. Existing solutions have downsides such as high costs, long and tedious production times, high complexity resulting in a lack of scalability, or an inability to meet material requirements for accurately simulating human tissue.

The objective of this work is to develop principles for a low-cost, easy-to-use 3D printing system capable of prototyping with soft tissue-mimicking materials. To pursue this goal, a MyCobot280 robot arm was used as the mechanism to explore the …

Fire Fossils: Biomineral Infrastructures In Untangling Climates, Tanmayee More

Masters Theses

Diatoms drift, sediments sink, wildfires generate their own weather. Lightning strikes can blast sand into glass, and microscopic organisms do the same in the cold recesses of the ocean. What alchemies and metabolisms catalyze space, time, and energy? What are the thermodynamics of infrastructure in Climate Change?

Places, materials, and beings are afterimages. Through alchemical experiments, and multi-scalar imaging, I develop simulations of wildfires, and their profound, reverberating effects. In this thesis, a glass-meets-landscape experimental process enters these obscured conditions and renders new material relations for the built environment.

Using Predictive Analytics To Reduce Small Business Cost Estimation Error, Diana Solt

Journal of Applied Packaging Research

Small and medium packaging companies generally employ the use of custom-developed quoting programs to bid goods and services. Custom bid programs (e.g. Excel) are used to capture the company-specific costs of production. The inputs of variable costs, such as machine rate and scrap rate, are critical to get correct; however, companies often rely on educated guesses and industry expertise to quote packaging products to end-users. Due to the guesswork involved there can be a financial difference between the quoted costs and actual costs. This variance is often the cause of significant lost dollars. Price, if not determined correctly, could negatively …

Production Of Sustainable Liquid Fuel From Waste Polymeric Materials Via Thermal Pyrolysis, Md. Sabbir Ahmed, Selim Reja, Sk Md Ali Zaker Shawon, Farhana Nazmin, Abdullah Mohammad Sarjish, Yousuf Ali, M. Azizur R. Khan, M. Jasim Uddin, Md. Wasikur Rahman

Mechanical Engineering Faculty Publications

The widespread use of polymeric materials has become an environmental threat as they are durable and nonbiodegradable in nature, which is directly responsible for severe ecological consequences. Thermal pyrolysis offers a sustainable and efficient approach to converting these polymeric waste materials into liquid fuel, which is also referred to as pyrolysis oil (PO). In this study, a novel method was developed for producing oil from a composite of waste polymers that include vehicle tires, tubes, and medical waste. A fixed-bed stainless steel reactor is used to thermally breakdown the waste polymeric feedstock (300–750°C) in an inert environment. The PO was …

Thermal Characterization Of 3d Printing Materials For Increasing Insulation Potential And Practicality, Jackson H. Minnick

Mechanical Engineering Undergraduate Honors Theses

This study served as an exploration into the possible existence of a correlation between the infill lattice structure of a 3D printed wall section and the thermal performance of that sample as characterized by thermal conductivity measured in units of Watts per meter Kelvin. With the continual increase in the practicality, fidelity, and applicable fields of additive manufacturing, namely FDM 3D printing, research on specific print characteristics and their effects on the material and thermal characteristics of the part in question is steadily becoming more commonplace. Although the thermal conductivity of 3D printed wall sections as a function of infill …

Integrity Assessment Of Shipping Line Pipelines Using Risk-Based Analysis To Determine Risk And Maintenance Strategies, Ade Ratih Anggraini, Dwi Marta Nurjaya

Journal of Materials Exploration and Findings

Pipeline Shipping Lines X, Y & Z are classified as critical infrastructure, being the only transportation through the crude oil lifting from P and R location to the transfer station in NM Area. To maintain the workflow of the Shipping Line, integrity assessments and risk evaluation are required to ensure the operational and safety. Anomalies were found by analysing inspection, monitoring, and repair data, while the pipelines' future integrity was assessed by calculating the remaining life. Risk-Based Analysis (RBA), which is a modification of Kent Muhlbaeur's method, is employed to conduct the risk assessment using the Probability of Failure (POF) …

Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa

Journal of Materials Exploration and Findings

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (p_{H₂S …}

Ultrafast Laser Surface Structuring For Wettability Control On Copper, Akshay Arvind Nagvenkar

All Theses

Wettability is a crucial surface property influencing various phenomena, including heat transfer, cell adhesion, and corrosion. Engineering devices can achieve superior performance by precisely manipulating surface wettability. As a result, extensive research has focused on developing surfaces that exhibit either extreme water attraction (superhydrophilic) or strong water repellency (superhydrophobic). Tailoring surface wettability paves the way for numerous applications, such as drag reduction in marine vessels, controlled drug delivery, efficient water collection, advanced liquid transport systems, oil-water separation, anti-corrosion coatings, friction reduction, and self-cleaning materials. Ultrafast laser surface structuring is a promising approach for engineering multifunctional surfaces, effectively modifying material properties …

Developing Reduced Order Models For Gas Bubble Formation In Irradiated Metals Using Integrated Phase Field Modeling And Koopman Operator Theory, John M. Eggemeyer V

All Theses

Irradiation damage in materials is prevalent in nuclear components, posing significant risks in the safety and reliability of nuclear reactors. Phase field models offer a versatile framework for modeling irradiation damage in materials at mesoscales. Such high fidelity method has been used to model the formation of fission gas bubbles superlattice, a microstructure array occurs at certain irradiation conditions (dose, dose-rate, and temperature). To overcome the high computational cost of phase field modeling, Koopman operator theory is applied to create reduced order models, allowing for instantaneous simulations of fission gas bubble behaviors. These low fidelity models are integrated into machine …

Mechanistic Insights Into Polymer-Assisted Graphene Exfoliation: The Roles Of Velocity, Adhesion, Cohesion, Temperature, Peeling Mode, And Edge Defect Via Coarse-Grained Molecular Dynamics, Linjiale Dai

All Theses

Graphene exfoliation is a critical step in the fabrication of high-quality graphene

layers. However, the underlying fracture mechanisms remain poorly understood. In this

work, I employed coarse-grained (CG) molecular dynamics (MD) simulations to

investigate how factors such as interfacial binding energy, substrate cohesion, temperature,

peeling mode, and edge defects influence the outcome of the exfoliation process. To model

polymer-assisted mechanical exfoliation, I used a finite-size system in which multilayer

graphene (MLG) is sandwiched between two thin polymer films. Leveraging the

spatiotemporal efficiency of the CG model, I performed fifty simulation iterations per

parameter set and analyzed the results from a …

Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau

Honors Scholar Theses

Pulse shape analysis can be used to analyze radiation incident on a semiconductor diode detector. Finite element analysis (FEA) can be used to simulate high purity germanium detectors with user-specified geometry, impurity concentration, and bias voltage. Subsequent streamline calculation can be used to conduct pulse shape analysis for single and multiple site gamma-ray interactions within the detector volume. Cross sections of the detector can be visualized by contour plots of the electric field, drift velocity magnitude, and collection time, as well as t30 and t90 rise-time values.

Exploring Metal Additive Manufacturing In Martian Atmospheric Environments, Zane Mebruer

Mechanical Engineering Undergraduate Honors Theses

On-surface manufacturing is key to the success of a planetary colonization, especially that of Mars. However, traditional subtractive manufacturing processes are equipment, energy, and material intensive, meaning novel additive manufacturing (AM) processes must be pursued for this end. Selective laser melting, one of the most effective and versatile AM methods, would be incredibly beneficial to a Martian mission but requires an artificial argon atmosphere to create effective parts. The purpose of this study was to examine if carbon dioxide, the gas that makes up over 95% of Mars’ surface atmosphere, would be a sufficient substitute for argon in SLM fabrication. …

Adjustable Dynamometer Motor Mount, Garrett Carson Ng, Elijah Siegel Reuven, Ethan Fong, Daniel Larimer

Mechanical Engineering

The Cal Poly Electrical Engineering Department and sponsor Dr. Dolan needs a manufacturable motor fixture that securely aligns motors of various sizes with dynamometers. Previous lab motor fixtures could not accommodate motors of different sizes, making precise alignment between motors and dynamometers time-consuming and unreliable. Our team developed a modular, manufacturable fixture capable of aligning various motor sizes quickly, accurately, and securely, enhancing lab consistency and usability.

Development And Tribological Characterization Of Uhmwpe-Tin Composite Coatings Deposited By Electrostatic Spraying, Jarrod Keith Perez

Theses and Dissertations

The increasing demand for inert, wear-resistant, cost-efficient, environmentally friendly, and low-friction coatings has driven extensive research into polymer-based solutions. Among these, ultra-high-molecular-weight polyethylene (UHMWPE) has emerged as a strong candidate due to its low density, anticorrosion properties, self-lubricating nature, affordability, and ease of processing. However, its low load-bearing capacity limits its widespread use in high-stress tribological applications. To overcome this limitation, this project investigates the development and characterization of UHMWPE composite coatings reinforced with titanium nitride (TiN) particles at varying concentrations (2.5, 5, and 10 wt%) to enhance their mechanical properties and wear resistance.

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …