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Research On Rc-Uhpc Composite Slab Frame Culvert Technology In Wave-Affected Areas, Qiu Junfeng Jun 2025

Research On Rc-Uhpc Composite Slab Frame Culvert Technology In Wave-Affected Areas, Qiu Junfeng

Journal of China & Foreign Highway

To address the problems in the construction of offshore bridges and culverts such as the structures susceptible to waves,limited layout,and high cost of soft foundation treatment,this paper proposed a new technical solution for reinforced concrete and ultra-high performance concrete (RC-UHPC ) composite slab frame culverts.With supporting engineering,the ordinary box culvert was selected as a comparison scheme for technical and economic analysis,and the design points and construction procedures of new structures were introduced.Based on the calculation results of the overall bearing force,the bearing performance of the top slab under different load conditions was analyzed,along with an investigation of the secondary internal …


Inverse Analysis Of Thermal Parameters Of Concrete Box Girder Based On De-Bp Neural Network, Yao Yong, Yan Yu, Sun Bo Wen, Wang Yuesong, Jiang Tianyong Jun 2025

Inverse Analysis Of Thermal Parameters Of Concrete Box Girder Based On De-Bp Neural Network, Yao Yong, Yan Yu, Sun Bo Wen, Wang Yuesong, Jiang Tianyong

Journal of China & Foreign Highway

In view of temperature cracks in concrete box girders easily occurring during construction,an inverse analysis method based on uniform design theory and differential evolution back propagation (DE-BP ) neural network was proposed to accurately obtain the thermal parameters of concrete box girders and ensure the reliability of temperature analysis of concrete box girders.This method established the nonlinear relationship between the temperature peak of characteristic points and the thermal parameters through the DE-BP neural network.By using the uniform design method and the Abaqus finite element numerical model,130 sets of sample data were generated.Based on the ratio of 12∶1 for training samples …


Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui Jun 2025

Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui

Journal of China & Foreign Highway

As a new structure with sloping arch ribs and curved main beams,a skewed arch and curved beam bridge markedly differs from the conventional bridge in construction monitoring technology due to its complex structure and prominent spatial effect.To investigate the key technology in construction monitoring,this study took a long-span skewed arch and curved beam bridge as the engineering background and discussed construction process simulation analysis,field monitoring,and parameter identification and adjustment of the bridge.The results show that the plate-shell unit model has higher calculation accuracy and can comprehensively show the stresses in all directions of the bridge compared with the beam element …


Study On Aerodynamic Optimization Of Π-Shaped Cable-Stayed Bridge With Vortex-Induced Vibration In Mountainous Areas, Zeng Min, Liu Hanyun, Mao Na, Chen Baixiang, Han Yan, Li Chunguang Jun 2025

Study On Aerodynamic Optimization Of Π-Shaped Cable-Stayed Bridge With Vortex-Induced Vibration In Mountainous Areas, Zeng Min, Liu Hanyun, Mao Na, Chen Baixiang, Han Yan, Li Chunguang

Journal of China & Foreign Highway

Given vortex-induced vibrations of bridges caused by high wind attack angles in mountainous canyons,this study investigated the vortex-induced dynamic characteristics of a Π-shaped steel-concrete composite beam cable-stayed bridge in a mountainous canyon under high wind attack angles based on wind tunnel tests and examined aerodynamic measures for vortex suppression.Firstly,a finite element model of the bridge was established,and the dynamic characteristics of the bridge in both the completed and construction states were analyzed.Subsequently,a 1∶50 scale detailed segment model was designed based on similarity theory to analyze the vortex-induced vibration performance of the original main beam under conventional wind attack angles of …


Wind Tunnel Experiment On Wind-In Duced Vibration Performance Of Arch-Shaped Inclined Steel Bridge Tower In Construction Free-Standing State Using Ae Roelastic Model, Xu Peijun, Deng Fei Yun, Chen Shixuan, Zhang Jiren Jun 2025

Wind Tunnel Experiment On Wind-In Duced Vibration Performance Of Arch-Shaped Inclined Steel Bridge Tower In Construction Free-Standing State Using Ae Roelastic Model, Xu Peijun, Deng Fei Yun, Chen Shixuan, Zhang Jiren

Journal of China & Foreign Highway

This paper presented a wind tunnel experimental study on the wind-induced response characteristics of a rectangular-sectioned arch-shaped inclined steel bridge tower during the construction free-standing stage.A 1:50 scaled aeroelastic model was employed to conduct experiments at different wind yaw angles β (0°‒180°).The experimental results indicate:① under the uniform flow field,the tower in its free-standing state does not experience galloping when the bridge ’s wind speed reaches 60 m/s;② under the uniform flow field,the tower exhibits bending vortex-induced vibrations (VIVs ) along the bridge direction or transverse to the bridge direction.However,the amplitudes of the tower top displacements associated with these VIVs …


Analysis Of Mechanical Properti Es Of Integral Jacking Basket Arch Bridge During C Onstruction, Chen Tao, Qiu Jingkui, Wang Ji Jun 2025

Analysis Of Mechanical Properti Es Of Integral Jacking Basket Arch Bridge During C Onstruction, Chen Tao, Qiu Jingkui, Wang Ji

Journal of China & Foreign Highway

Taking the Xindian Bridge in Ni ngbo as the background,this paper analyzed the mechanical properties of the integral jacking basket arch bridge during construction.Midas finite element software was used to establish the spatial model of the main bridge,and the deviation of the suspender force and support reaction force of the completed bridge from the design was 1.84% and 1.8%,respectively.The maximum deviation of the displacement calculation of the tie beam at the bridge completion stage was 22 mm,and the maximum deviation of the displacement of the arch rib at the same stage was ‒ 12 mm,which showed that the finite element …


Numerical Simulation Study On Scour Erosion Of Bridge Pile Foundations In Service, Wang Shang, Mi Jiangchuan, Chen Mingtao, Song Dan, Zhang Qiao, Zhang Yong, Wang Weixiao Jun 2025

Numerical Simulation Study On Scour Erosion Of Bridge Pile Foundations In Service, Wang Shang, Mi Jiangchuan, Chen Mingtao, Song Dan, Zhang Qiao, Zhang Yong, Wang Weixiao

Journal of China & Foreign Highway

Bridge pile foundations in servic e are subjected to long-term scour erosion caused by sediment-laden water flow,leading to a gradual expansion of the eroded and worn areas.This in turn results in varying degrees of damage to the pile foundation structure and reduces the durability and safety of the bridge.In order to study the impact of scour erosion on bridge pile foundations,this study took the Hanjiang No.1 Bridge in Ankang City as the research object.The ANSYS FLUENT software was used to conduct three-dimensional numerical simulations of the pile foundation and analyze the distribution characteristics and patterns of scour erosion under different …


Internal Force Optimization In Com Pleted Stage And Construction Alignment Control Of Super Long-Span Extradosed Cable-Stayed Bridge, Ba Wenpeng Jun 2025

Internal Force Optimization In Com Pleted Stage And Construction Alignment Control Of Super Long-Span Extradosed Cable-Stayed Bridge, Ba Wenpeng

Journal of China & Foreign Highway

This paper is based on a super long-span extradosed cable-stayed bridge with a main span of 400 m.In view of the technical challenges of high negative bending moment at the quarter point of the bridge and large deformation during the cantilever assembly process in the non-cable area,a systematic solution was proposed in combination with the entire construction process.This paper proposed three schemes:permanent cable over-tensioning,temporary cable setting,and large segment closure.The bending moment ratio (λM) and structural deformation were used as quantitative indicators,and a finite element model was established to compare the three schemes.The results show that all three schemes can improve …


Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming Jun 2025

Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming

Journal of China & Foreign Highway

In order to determine reasonable grouting parameters,control surface settlement,and reduce the risk of excessive surface settlement caused by irrational synchronous grouting parameters,this study studied the shield tunnel project between maglev T 2 station and maglev T 3 station.A numerical simulation method was adopted to study the influence of grouting pressure,grouting volume,and the elastic modulus of slurry on surface deformation.The results show that the tunnel synchronous grouting has a significant effect on surface settlement control.A greater grouting pressure,equivalent grouting layer thickness,and elastic modulus of slurry mean a smaller surface settlement.As the three parameters increase,the variation range of surface settlement decreases and …


Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan Jun 2025

Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan

Journal of China & Foreign Highway

This study aims to address poor adaptability and timeliness in the design of smooth blasting hole parameters in t he past.With the drilling and blasting method-based construction of large cross-section tunnels in Botanggou and Tielugou along the Zunhua‒Qinhuangdao Expressway as the research background and Ⅲ and Ⅳ grade surrounding rocks of porphyritic granite as the research object,statistical regression analysis and theoretical derivation were conducted on the measured data during on-site drilling according to the rock solidity coefficient.Based on this,a simple parameter design method for a smooth blasting layer based on the drilling speed index of an air leg anchor rod …


Study On Reasonable Parameters Of Natural Smoke Exhaust Shafts In Tunnels With Different Longitudinal Slopes, Yang Tao, Zeng Yuekai, Li Peijun, Ren Rui, Deng Min, Zhang Aoyu Jun 2025

Study On Reasonable Parameters Of Natural Smoke Exhaust Shafts In Tunnels With Different Longitudinal Slopes, Yang Tao, Zeng Yuekai, Li Peijun, Ren Rui, Deng Min, Zhang Aoyu

Journal of China & Foreign Highway

To obtain the reasonable parameters of a smoke exhaust shaft in a tunnel under different longitudinal slope conditions,the temperature,flow velocity,and smoke exhaust efficiency of the tunnel were taken as indexes,and the numerical model was established by using fire dynamics simulator (FDS ) software to study the influence of the longitudinal slope of the tunnel,shaft width,and shaft length on the ventilation and smoke exhaust in case of a fire.The results show that under the longitudinal slope conditions,with the increase in the shaft width and length,the maximum temperature in the tunnel decreases,and the smoke exhaust efficiency of the shaft increases.However,the influence of …


Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan Jun 2025

Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan

Journal of China & Foreign Highway

In the field of fault-tolerant control for intelligent vehicle path tracking,the existing methods based on model predictive control (MPC ) have limitations.They often assume that the vehicle model parameters are fixed and ignore the impact of dynamic changes in model parameters,which are caused by factors such as vehicle load changes and external environmental interference,on the path tracking accuracy.When the steering system fails,the front wheel steering angle commands calculated by MPC cannot be directly executed and need to be converted into yaw moment control.Although the existing sliding mode yaw moment control methods have strong robustness,the chattering problem affects the stability and …


Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan Jun 2025

Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan

Journal of China & Foreign Highway

By analyzing the application points and the current situation of digital delivery in each stage of highway engineering construction,this study found that the lack of parameter management and definition in the modification and refinement process of building information modeling (BIM ) source files at each stage led to difficulties in the splitting and refinement of BIM at each stage and even the need for reconstruction.To this end,a method for strengthening the overall planning of the whole life cycle was proposed.By clarifying the demand for model parameters according to the application points of each stage,a mechanism for parameter reservation and classification …


Reconstruction Plan Of Small-Spacing Interchange Connection Sections On Expressway : A Case Study Of Xinlong‒Gangkou Interchange On Zhongshan‒Jiangmen Expressway, Jie Qiang, Fu Xinsha Jun 2025

Reconstruction Plan Of Small-Spacing Interchange Connection Sections On Expressway : A Case Study Of Xinlong‒Gangkou Interchange On Zhongshan‒Jiangmen Expressway, Jie Qiang, Fu Xinsha

Journal of China & Foreign Highway

The plan design for the small-spacing interchange connection on the expressway directly affects operational efficiency and driving safety.To achieve the conversion of traffic flow between different expressways,this study explored the reconstruction plan of the connection section under the condition that the interchange spacing did not meet the Design Specification for Highway Alignment (JTG D20‒2017 ) and investigated two connection schemes,including auxiliary lane and collector-distributor lane by taking the Xinlong –Gangkou interchange of the Zhongshan‒Jiangmen Expressway reconstruction and expansion project as an example.The results show that the auxiliary lane is recommended in consideration of the long-term service level,speed coordination,operational efficiency,and engineering …


Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou Jun 2025

Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou

Journal of China & Foreign Highway

To lift the longitudinal section of existing bridges in highway reconstruction and expansion projects due to insufficient under-bridge clearance,this study took the reconstruction of a 32.5 m T-beam bridge in the reconstruction and expansion project of the Guangzhou‒Shenzhen Expressway as the research object.By using a carbon emission factor method,carbon emissions of three reconstruction schemes,including broken-column jacking,conversion of bearing pads into bridge piers,and demolition and reconstruction,were calculated under different lifting heights,and the corresponding construction and installation costs were compared.The results show that when the longitudinal section of the bridge is lifted to a certain height,the economic benefits of the broken-column jacking …


Comparative Study On Differences In Asphalt Pavement Design Between China And Southern Africa, Wang Qing, Lin Yangyang, Yan Hongxiang, Zhao Bin, Xia Moxuan, Li Ning, Si Wei Jun 2025

Comparative Study On Differences In Asphalt Pavement Design Between China And Southern Africa, Wang Qing, Lin Yangyang, Yan Hongxiang, Zhao Bin, Xia Moxuan, Li Ning, Si Wei

Journal of China & Foreign Highway

To facilitate the successful implementation of projects in the Southern Africa region and promote the application and internationalization of China ’s standards,this study compared the asphalt pavement design systems,construction materials,design parameters,and structural design methods of both regions based on the main asphalt pavement design specifications currently in use in China and Southern Africa.The results show that among Southern African countries,South Africa has a comprehensive and widely applied standard system,while other Southern African countries adopt more varied and less theoretical standards.In contrast,China ’s standard system is complete and highly practical.Due to differences in regional climates,the selection principles and mechanical requirements for …


Distribution Characteristics Of Internal Distress And Maintenance Decision-Making For Asphalt Pavement Based On Three-Dimensional Ground-Penetrating Radar, Li Xiaohua, Song Liang, Ye Wei, Xie Xiaodong, Yang Jiangang, Gao Jie Jun 2025

Distribution Characteristics Of Internal Distress And Maintenance Decision-Making For Asphalt Pavement Based On Three-Dimensional Ground-Penetrating Radar, Li Xiaohua, Song Liang, Ye Wei, Xie Xiaodong, Yang Jiangang, Gao Jie

Journal of China & Foreign Highway

The distribution characteristics of internal distress in pavement structures and the corresponding maintenance decisions are crucial for improving road performance and extending service life.Based on three-dimensional ground-penetrating radar (3D GPR ) technology,this study investigated the internal distress of a 12-kilometer section of both driving and overtaking lanes of an expressway in Hubei Province.High-resolution images of internal pavement distress were obtained,and milling maintenance decisions were optimized by employing these images and a modular decision-making model.Through an efficient and non-destructive technique,the distribution characteristics of internal pavement distress were analyzed,and potential distress types were identified,providing a scientific basis for maintenance decision-making.Data analysis revealed …


Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader Jun 2025

Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader

Journal of China & Foreign Highway

The Champlain Bridge,an iconic gateway spanning the St.Lawrence River in Montreal,showcases not only the excellence of engineering but also becomes an integral part of the city ’s landscape.With a main span of 240 m,the bridge employs a unique single-pylon harp-shaped double-plane cable-stayed structure.The upper pylon is inspired by a tuning fork in its lateral design,while the upper crossbeam artfully mimics the shape of a bow tie,endowing the bridge with a visual beauty that harmoniously blends elegance and strength.The bridge deck,with a total width of 60 m,was the widest double-plane cable-stayed bridge in the world when it was completed.The typical spans …


Modeling And Estimation Of Co2 Capture By Porous Liquids Through Machine Learning, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, John L. Zhou, Ali Altaee Jun 2025

Modeling And Estimation Of Co2 Capture By Porous Liquids Through Machine Learning, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, John L. Zhou, Ali Altaee

Chemical and Biochemical Engineering Faculty Research & Creative Works

Porous liquids (PLs) are newly developed porous materials that combine unique fluidity with permanent porosity, which exhibit promising functionalities. They have shown ability to efficiently absorb greenhouse gases such as carbon dioxide (CO2). Experimental measurement is one approach to determining the solubility of various greenhouse gases in PLs, which has drawbacks such as being expensive and time-consuming. Hence, simulation models are valuable to predict the solubility of CO2 in various PLs. This work aims to develop machine learning (ML) modeling methods for accurately estimating CO2 solubility under varying conditions (e.g. PLs, temperature, pressure). Adaptive Neuro-Fuzzy Inference …


Camino—Career Advancement, Mentorship, Inspiration, And Opportunities: A Stem K-12 Outreach Initiative, Hector A. Pulgar, Francisco Zelaya-Arrazabal, Erick Salvador Vasquez, Sebastian N. Martinez Lizana Jun 2025

Camino—Career Advancement, Mentorship, Inspiration, And Opportunities: A Stem K-12 Outreach Initiative, Hector A. Pulgar, Francisco Zelaya-Arrazabal, Erick Salvador Vasquez, Sebastian N. Martinez Lizana

Chemical and Materials Engineering Faculty Publications

CAMINO is a STEM program designed to promote career advancement, provide mentorship, give inspiration, and offer opportunities for K-12 Hispanic students located in East Tennessee. As part of the educational component of an NSF CAREER grant, the program launched in 2021 and is a collaboration between a research group from the University of Tennessee and one of the high schools with the largest Hispanic populations in the Knoxville Metropolitan area. These students from minority backgrounds may limit their aspirations and may not pursue higher education and/or professional development for numerous reasons, such as limited motivation, insufficient exposure to higher education, …


Entrepreneurially Minded Learning (Eml) Micromoment Activities Generated Using Students' Experiences In A Fluid Flow And Heat Transfer Course, Erick Salvador Vasquez, Megan Morin Jun 2025

Entrepreneurially Minded Learning (Eml) Micromoment Activities Generated Using Students' Experiences In A Fluid Flow And Heat Transfer Course, Erick Salvador Vasquez, Megan Morin

Chemical and Materials Engineering Faculty Publications

The Entrepreneurially Minded Learning (EML) Framework involves the 3 C's: curiosity, connections, and creating value. Several design courses, open-ended assignments, and laboratory experiences can successfully lead to EML implementations. However, these implementations require extensive class time and instructor feedback, limiting their use in core engineering courses. Developing EML activities that are active, engaging, and rapid to deploy in a classroom setting can promote the sustained growth of an entrepreneurial mindset (EM). EML micromoment activities are emerging as a practical tool to facilitate the incorporation of the 3 Cs through rapid activity implementations that only last 2 – 30 minutes. These …


Utilization Of Rubber Tire Composition For The Mechanical And Dynamic Performance Of An Energy Dissipation Damper, Ahmed Sami Hasan Al-Osta Jun 2025

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 …


Investigating The Properties Of Eco-Bricks Composed Of Sawdust, Bamboo, And Varying Composition Of Sugarcane Bagasse Ash And Portland Cement, Wilfred Victor C. Marasigan, Julia Sophia Antonia S. Encarnacion, Czyrus Michael A. Bajeta, Alijah F. Gonzales, Juan Carlo T. Gumangan Jun 2025

Investigating The Properties Of Eco-Bricks Composed Of Sawdust, Bamboo, And Varying Composition Of Sugarcane Bagasse Ash And Portland Cement, Wilfred Victor C. Marasigan, Julia Sophia Antonia S. Encarnacion, Czyrus Michael A. Bajeta, Alijah F. Gonzales, Juan Carlo T. Gumangan

Sinaya: A Philippine Journal for Senior High School Teachers and Students

With the construction industry contributing nearly 40% of global greenhouse gas emissions, there is a growing need for innovative and sustainable building materials. This research investigates a new eco-friendly concrete brick incorporating sugarcane bagasse ash (SCBA), sawdust, and bamboo fibers. Three eco-brick mixtures, each containing 2% bamboo fiber and 10% sawdust by weight but with varying proportions of Portland cement (PC) and SCBA, were tested against a standard brick for compressive strength, flexural strength, and water absorption. The optimal mixture, with 2% bamboo fiber by weight, 10% sawdust by weight, 85% PC, and 15% SCBA, exhibits compressive and flexural strength …


Shrinkage Study In Photopolymerisable Hybrid Sol-Gel Through Holographic Patterning, Jamshed Aftab, Izabela Naydenova, Tatsiana Mikulchyk Jun 2025

Shrinkage Study In Photopolymerisable Hybrid Sol-Gel Through Holographic Patterning, Jamshed Aftab, Izabela Naydenova, Tatsiana Mikulchyk

Articles

Photopolymerisation induced shrinkage of holographic materials is one of the main factors which needs to be considered for designing holographic optical elements (HOEs) with high accuracy in light redirection with maximum efficiency. This work studies the shrinkage in photopolymerisable hybrid sol-gel (PHSG) by examining the properties of volume transmission gratings recorded in PHSG layers. It explores both the dependence of shrinkage on the holographic grating parameters (thickness, spatial frequency, slant angle) and the effect of material aging. By using the fringe-plane rotation model, shrinkage is found to have the maximum value of 1.37 % at 765 lines/mm (19.36° slant angle) …


Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat Jun 2025

Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating earth concrete (SCEC) addresses the long construction process of conventional earthen constructions and their structural limitations, while further efforts are needed to enhance its sustainability. This study explores the development of a kaolinite-based self-consolidating earth paste (SCEP) due to their blended powder system, incorporating raw and treated (calcined and ground-calcined) kaolinite under various activation techniques, such as water hydration, sodium hexametaphosphate (NaHMP), and sodium hydroxide (NaOH) activation. The synergistic effect of calcination and mechanosynthesis on rheological, mechanical, structural, and microstructural properties of SCEP were investigated. Mechanically treated kaolinite increased yield stress, plastic viscosity, storage modulus evolution, and build-up index, …


Measurement And Process Relation For Cast Surface Defects, Nachiket Laxman Shinde Jun 2025

Measurement And Process Relation For Cast Surface Defects, Nachiket Laxman Shinde

Masters Theses

This thesis presents an in-depth investigation into the classification and prediction of surface defects in aluminum sand castings using a combination of experimental trials and machine learning techniques. Key process variables such head height, pouring temperature, resin %, sand type and process were systematically varied to study their influence on defects like veining, and burn-on. Comparative analysis indicated superior performance of the deep learning model in handling nonlinear interactions between process parameters. The study emphasizes the importance of integrating data-driven models with foundry practices to enhance surface quality, reduce rework, and support intelligent decision-making in casting operations.


Model-Based Design Of Compressed Lithium-Metal Pouch Cell Battery Modules For Evtol Applications, Scott J. Stirling Jun 2025

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 …


Low Earth Orbit Drag Sail Degradation Due To Atomic Oxygen And Ultraviolet Radiation, Hannah Rost Jun 2025

Low Earth Orbit Drag Sail Degradation Due To Atomic Oxygen And Ultraviolet Radiation, Hannah Rost

Master's Theses

As the orbital debris population increases, so does the risk of collisions with operational spacecraft. In response, the Federal Communications Commission has shortened the deorbit requirement from 25 years to five years. While natural atmospheric decay was sufficient under the previous guideline, many objects with low area to mass ratios can no longer passively comply. Smaller, non-propellant-carrying space objects such as CubeSats lack the ability to maneuver and must rely on alternative deorbit methods. One proposed solution is to deploy a drag sail at end of life to increase atmospheric drag and accelerate orbital decay. However, exposure to atomic oxygen …


In-Situ Defect Detection In Selective Laser Melting Using Convolutional Neural Networks, Ethan Gaigalas Jun 2025

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, …


Investigation Into Silicone-Silicate Conversion Due To Atomic Oxygen In The Low Earth Orbit Environment, Justin T. Self Jun 2025

Investigation Into Silicone-Silicate Conversion Due To Atomic Oxygen In The Low Earth Orbit Environment, Justin T. Self

Master's Theses

Silicones have been widely used over the years in spacecraft for a variety of functions, but atomic oxygen (AO) exposure in Low Earth Orbit causes a silicate (SiO2) surface layer to rapidly develop on the silicone which results in a permanent change in its thermal and optical properties. Although this silicone to silicate conversion is known to occur, statistical predictions of layer formation as a function of time on orbit are not found in literature. This thesis utilized optical and scanning electron microscopy, Fourier-Transform Infrared Spectroscopy, diffuse reflectance spectroscopy, and nonlinear regression statistical techniques after RF plasma asher …