Materials Science and Engineering Commons^™

Dynamic Responses Of Super‑Wide Self‑Anchored Suspension Bridge Under Blast Loading, Zhou Guangpan, Lin Zhicheng, Fan Jin, Wang Mingyang

Journal of China & Foreign Highway

To study the dynamic response and damage characteristics of the super-wide concrete self-anchored suspension bridge under the blast loading,a real bridge with these characteristics was selected as the background,and the numerical simulation was used to analyze the dynamic response of the top surface crack shape and the vertical displacement of the bottom plate of the super-wide box girder under the close blast of the bridge deck.Firstly,the refined finite element model of the whole bridge was established by using SolidWorks and HyperMesh.Secondly,the blast loading was applied by Ansys/LS-DYNA and *LOAD_BLAST_ENHANCED (LBE ) method,and the reliability of the calculation method was verified …

Fatigue Analysis Method Through Load Spectrum Considering Cyclic Characteristics For Highway Bridges, Sun Liangfeng, Zheng Xianglong, Shen Mingjiang

Journal of China & Foreign Highway

No abstract provided.

A Rapid Test Method For Deflection Of Small And Medium‑Span Bridges, Zhang Aipin, Ma Lindong, Chang Zhugang, Fan Zhihao

Journal of China & Foreign Highway

Bridge deflection response is on e of the most important indicators used for structural condition assessment of bridges.There are currently many methods and devices for deflection measurement,but they are not satisfying in terms of economy,applicability,and measurement accuracy at the same time.This paper proposed a rapid and highly accurate method for measuring mid-span deflection of small and medium-span bridges.By using the high accuracy of displacement transducers in direct contact measurement,an auxiliary measurement device was developed to transfer the deflection of the measurement points on the bridge to the displacement transducer in the form of a rigid connection,thus achieving accurate and dynamic …

Numerical Simulation Of Mechanical Performance For Anti‑Collision Steel Pontoon, Han Xiaolei, Wang Bo, Li Weidong

Journal of China & Foreign Highway

Anti-collision steel pontoo n has good plasticity and energy absorption properties in ship-bridge collision.To explore the factors affecting the anti-collision performance of the anti-collision pontoon,a collision model composed of ship,anti-collision pontoon,and pier system was built based on finite element software Ansys/LS-DYNA.The collision mechanism and process were numerically simulated,and the effects of connection type between anti-collision pontoon and pier,peak angle of pontoon,and anti-collision pontoon stiffness on the collision force of the pier were investigated.The three-stage division method of collision force curve was put forward.The analysis shows that the fixed inwall of the anti-collision steel pontoon and connection to the pier surface …

Stress And Deformation Of Retaining Structure In Narrow And Long Foundation Pit Based On Steel Braces, Xu Liwu, Chen Zhuoyi, Qiu Lijie

Journal of China & Foreign Highway

Based on a large deep foundation pit project,the deformation characteristics of the pit support enclosure system,force characteristics,and changing trend of surrounding ground surface settlement during the excavation process of the narrow and long deep foundation pit with steel braces were studied through automated monitoring and numerical simulation.Midas GTS was used to establish the pit model,and the effects of the horizontal spacing of the steel brace,the distance of the third steel brace from the bottom of the pit,the preloaded axial force of the steel brace,and the change of the pile diameter of the pit enclosure on the deformation and force of …

Deformation And Damage Characteristics Of A Newly Operated Tunnel Caused By Above Foundation Pit Construction, Liu Jiqiang, Zhu Min, Hao Kun, Chen Dengwei, Chen Xiangsheng

Journal of China & Foreign Highway

The construction of foundation pits in granite residual soil layers is prone to causing upheaval deformation and structural damage in shield tunnels below.Based on the engineering case of a newly operated metro tunnel collinear with the above long-distance deep foundation pit in Shenzhen,a three-dimensional finite element model was established to investigate the variation law of the heave and horizontal convergence of the shield tunnel caused by the deep foundation pit excavation.The correlation between the longitudinal stress of the lining structure and the damage was analyzed.The results indicate that the tunnel deformation caused by foundation pit unloading is primarily vertical heave,accompanied …

Calculation Analysis Of The S Urrounding Rock Pressure In Shallow Buried Unsymmetrial Tunnel Under Variable Slope, Bai Yan, Qiao Ting Ting, Ning Xiaojun, Liu Guokun

Journal of China & Foreign Highway

To provide a reasonable meth od for calculating the surrounding rock pressure in shallow buried unsymmetrial pressure tunnels under variable slope conditions for tunnel design,to establish a model for calculating the surrounding rock pressure in shallow buried unsymmetrial pressure tunnels under variable slope conditions,and to employ the principle of ultimate equilibrium to derived the formula for calculating the surrounding rock pressure.The intermediate variable β' is introduced as the base for selecting the unsymmetrial pressure tunnels surrounding rock pressure calculation method under variable slope conditions,and the derived formulas in this paper are verified by comparing the calculated values of the normative …

Dynamic Response Rules Of Adjacent Buildings To Blasting Construction In Shallow Buried Tunnels, Luo Yanping, Li Jigang, Wang Sheng, Zeng Bin, Lai Jinxing, Feng Zhihua, Qiu Junling

Journal of China & Foreign Highway

In order to study the dynamic response rule of overlying buildings during blasting construction in shallow buried tunnels,the urban tunnel in Fuzhou was taken as the engineering background,and the on-site monitoring and Ansys/LS-DYNA simulation were used to analyze the structural response of overlying buildings.The monitoring results show that the building is most obviously affected by blasting in the vertical direction and has an obvious elevation amplification effect,and the maximum vibration velocity is 2.45 cm/s.The vibration velocity in all directions gradually decreases and tends to be stable with the increase in explosion center distance and decays rapidly when the explosion center …

Correlation Analysis Of Highway Traffic Accidents Based On Improved Apriori Algorithm, Qiu Wenli, Yang Haifeng, Zhang Shaobo, Qiu Yu, Zhao Jiao

Journal of China & Foreign Highway

In order to explore the as sociation characteristics between influencing factors of accidents from existing traffic data and provide precise and fine-grained decision support information for highway operation and management departments,a constrained improved Apriori algorithm was established to mine the association rules affecting highway traffic accidents by considering four dimensions:driver,environment,road,and vehicle.On the basis of the traditional Apriori algorithm,the improvement of antecedent and consequent constraints of the rule may increase the accuracy and efficiency of mining association rules.Based on the analysis of 3 178 highway traffic accident data,it is shown that the improved Apriori algorithm reduces the number of invalid association …

Characteristics And Safety Of Weaving Areas Of Trunk Roads Based On Traffic Conflicts, Wang Ziming, Li Shubin, Cui Shuai

Journal of China & Foreign Highway

This paper selected a weaving area on Jingshi Road in Jinan,China as the investigation object to study the characteristics of traffic conflicts and the safety level of each lane in the weaving area between the entrance of an urban trunk road and a signal-controlled intersection.In this research,a signal period was set as the investigation interval,traffic conflicts were identified as the research basis,and the collision time (TTTC) was selected as the index.Severity thresholds of traffic conflicts were established by using the cumulative frequency method,and a model was constructed to represent the relationship among the overall traffic volume,traffic density,and the number of …

Safety Of Optimized Concrete Median Barrier Without Planting Soil, Zhong Chunyao, Ma Qing, Li Yangfan, Gong Shuai, Liu Siyuan, Yan Shuming

Journal of China & Foreign Highway

In order to study the safety of optimized concrete median barrier without planting soil,the technology combining computer simulation,sled test,and full-scale impact test of real vehicles was adopted for analysis and verification.In addition,a scheme was proposed to improve the anti-overturning ability of the barrier without planting soil by strengthening the supporting block,and the scheme of setting a 20 cm-high supporting block between the barrier walls was optimized.The safety of the barrier scheme was evaluated by taking the most unfavorable large truck as an example.The results show that the protection level of the optimized concrete median barrier without planting soil is SAm, …

Aided Design Method And Application Of Rutting Prevention And Maintenance In Asphalt Pavement Based On Digital Holographic 3d Detection, Wang Jingfei, Wang Wang, Xu Xinquan, Huang Zhijian, Ti Jing, Yao Yanru

Journal of China & Foreign Highway

As one of the common diseases of asphalt pavement,rutting has significant impacts on the service life and traffic safety of the pavement.Mild rutting in asphalt pavement during preventive maintenance can lead to increased use of maintenance materials due to rutting deformation.Accurately calculating the amount of materials needed to fill rutting in maintenance designs is of great significance for ensuring maintenance quality and efficiency.Based on the requirements of maintenance engineering,this paper analyzed the problems in maintenance designs that use traditional methods and the data they generate for rutting detection.A design method was proposed for rutting prevention and maintenance in asphalt pavement,assisted …

Performance Of Chlorine Salt Snow‑Melting Agent Based On Improved, Shrp Ice‑Melting Testlyu Yuejing, Dang Bo, Zhang Zhiwei, Tang Wen, Fan Yu

Journal of China & Foreign Highway

Chlorine salt snow-melting agent has been widely used because of its excellent ice-melting and snow-removing performance,low price,and easy access.In order to explore the problems of different temperature applicability,non-uniform standard,and rough spreading methods of chlorine salt snow-melting agents,this paper analyzed the influence of temperature,solid and liquid state,and spreading methods on the ice-melting performance of three commonly used chlorine salt snow-melting agents,namely NaCl,CaCl2,and MgCl2,through an improved SHRP ice-melting test.The test results show that the ice-melting performance of the chlorine salt snow-melting agent has strong temperature sensitivity.MgCl2 and CaCl2 snow-melting agents have an exothermic effect during the melting process.The ice-melting efficiency of the …

Deflection Basin Characteristics Of Distressed Roads Under Moving Load, Cai Yingchun, Xie Shenjian

Journal of China & Foreign Highway

The deflection basins of roads under moving load imply the distress information of subgrade and pavement.Therefore,how to use the information of deflection basins under moving load to rapidly test road distresses non-destructively has received much attention.In this paper,the finite element model of semi-rigid base asphalt pavement was established.By setting different types and degrees of finite element distress models,the continuous changes of surface deflection basins under moving load were analyzed.The results show that when the load moves to the distress area,the center deflection value of surface deflection basins in each distress model will become larger.When transverse cracks appear in the pavement …

Curing Mechanism And Influencing Factors Of Cement Mixing Piles Reinforcing Peat Soil, Feng Rongxian, Zhong Gaibing, Liu Liang, Liang Jianyuan, Gu Meixiang

Journal of China & Foreign Highway

The cement mixing pile is used to reinforce the deep peat soil foundation in Malaysia's east coast railway construction.The key in this project is to determine the cement mix proportion and additives.Considering the high organic matter content and strong environmental acidity of coastal peat soil,physical and mechanical tests of peat soil and laboratory uniaxial compression tests of cement soil under different mix proportions and influencing factors were conducted.Test results show that the mean compressive strength decreases by 0.35 MPa with the increase in cement-water from 0.5 to 0.9.Adding mineral powder gives a relatively poor curing effect while adding fly ash …

Photodegradation And Microencapsulation Of Organic Thermochromic Material For Application As Building Coating Envelope, Sushant Madhukar Nagare

USF Tampa Graduate Theses and Dissertations

Due to exponential urbanization, residential building electrical loads have increased over the past decades. Also, deforestation has led to increased urban heat island effects, due to which summer has been scorching and winter has become freezing. This further increases the load on generation due to the extensive use of heating and cooling systems. New techniques, such as cool building materials and green building concepts, compensate for the load. The building can be coated with a material that has heat reflectivity capability for summer and heat-trapping capability for winter. One such material is thermochromic, which turns white upon heating and black …

Design, Fabrication, And Characterization Of Multifunctional Cellular Structures For Enhanced Impact Energy Mitigation Performance, Kazi Zahir Uddin

Theses and Dissertations

This dissertation investigates the relationship between the structural design of cellular solids and their macroscopic behavior and focuses on the customization of properties through advanced fabrication techniques. The concepts of density gradation and their integration in both non-ordered and ordered cellular structures have been proposed. The investigation focuses on the development of functionally graded foam materials (FGFMs) and mechanical metamaterials to obtain tunable mechanical performance. One significant focus is the fabrication of density-graded foam stacks with various interface adhesives. From the insights gained from the study of interfaces in density-graded foams, certain design and fabrication principles are applied to enhance …

Investigation Of The Use Of Recycled Concrete Aggregates In Porous Asphalt Mixture, Asad Elmagarhe

USF Tampa Graduate Theses and Dissertations

This study aims to address the national need for using recycled concrete in road pavements. This is especially important in the governmental and corporate sectors, where reducing the cost and carbon footprint of construction projects is a priority. The long-term goal is to meet the public demand for environmentally friendly infrastructure and minimize the harmful effects of waste disposal on humans and the environment.

The project focuses on using recycled concrete aggregate (RCA) in porous asphalt pavement to reduce stormwater runoff, a popular environmentally friendly road design. However, compared to regular dense asphalt mixtures, porous asphalt mixtures (PAM) are more …

A First Step Towards Understanding Thermomechanical Behavior Of The Nb-Cr System Through Interatomic Potential Development And Molecular Dynamics Simulations, Lucas A. Heaton, Adib J. Samin

Faculty Publications

Utilizing a preliminary interatomic potential, this work represents an initial exploration into the thermomechanical behavior of NbCr solid solutions. Specifically, it examines the effect of different amounts of Cr solute, for which information in the literature is limited. The employed interatomic potential was developed according to the embedded atom model (EAM), and was trained on data derived from density functional theory calculations. While the potential demonstrated reasonable accuracy and predictive power when tested, various results highlight deficiencies and encourage further development and training. Mechanical strength, heat capacities, thermal expansion coefficients, and thermal conductivities were found to decrease with Cr content. …

Continuum Mechanics Modeling Of High Strain Rate Impact Of Thermoplastic Polymer Particles, Jeeva Muthulingam

Theses and Dissertations

The study of particle impact at high strain rates is crucial in fields ranging from materials science and engineering to space exploration and environmental science. In the particular case of cold spray, a particle undergoes intense plastic deformation upon impact, causing it to adhere to the target substrate. While metallic particles impacting on metallic substrates have been extensively studied, understanding the mechanical characteristics of polymeric particles on polymer and metal substrates requires further research. This study focuses on single particle impact modeling, analyzing impact parameters such as particle size, velocity, and angle of incidence using continuum mechanics finite element modeling …

Investigation Of Process-Structure-Property Relationships In Additively Manufactured Chopped Fiber-Reinforced Polymer Composites, Indu Modala

Theses and Dissertations

Fiber-reinforced polymer (FRP) composites are widely used in various industries because of their high stiffness-to-weight ratio. However, traditional manufacturing processes restrict the application of FRP composites to the production of parts with simple geometries. With the advent of additive manufacturing (AM), it is possible to produce topologically optimized parts with complex geometries using chopped FRPs. Fully leveraging the advantages of AM in the fabrication of chopped FRP parts requires a thorough understanding of the effect of the process parameters on the microstructure, and subsequently on the mechanical properties of the manufactured part. This research focuses on studying the process-structure-property (P-S-P) …

Extreme Value Statistics Analysis Of Process Defects In Additive Manufacturing Materials, Ayorinde E. Olatunde, Kristen Hernandez, Austin Ngo, Arafath Nihar, Thomas G. Ciardi, Rachel Yamamoto, Pawan K. Tripathi, Roger H. French, John J. Lewandowski, Anirban Mondal

Faculty Scholarship

Fatigue and fracture studies focused on process defects that occur in Additive Manufacturing (AM) materials have shown that defect populations possess features which are better measured with extreme value statistics (EVS). In AM alloys, defect occurrences increase with material volume. This situation facilitates the need to model process defects in the path of fatigue crack growth with suitable statistical tools, such as EVS, which is more cost-effective when compared to destructive experiments. The application of EVS on defect space features helps determine the difference in defects present on fracture surfaces. As the fatigue quality of any material depends on its …

New Generation Graphenes In Cement-Based Materials: Production, Property Enhancement, And Life Cycle Analysis, Sahil Surehali, Sayee Srikarah Volaity, Aswathy Simon, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Several studies have explored the use of graphene to improve the properties of cement-based materials. However, most commercially available graphenes are expensive, not amenable to mass production, and have high embodied energy and emissions, making their use in concrete less attractive, despite the beneficial mechanical property attributes. This paper discusses the use of two novel graphene types, fractal graphene (FG) and reactive graphene (RG), obtained through a cost-effective and scalable detonation synthesis, in cement-based materials. FG and RG are sheets containing 6-10 layers, with lateral dimensions of 20-50 nm and a z-axis thickness of RG, when added at very small …

Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez

Electronic Theses and Dissertations

Recent efforts have been exploring the use of thin film synthetic ferrimagnets and disordered magnetic oxides for applications in spintronic devices. Due to the antiferromagnetic exchange interaction, ferrimagnetic materials offer the ultrafast dynamics of the antiferromagnetic exchange, with a net magnetization that can be influenced externally. With two, or more, competing ferromagnet sublattices, interesting properties arise that depend on the final magnetic landscape after growth of the material and it’s inherent magnetic anisotropy energies. Properties such as magnetic compensation temperatures, and perpendicular magnetic anisotropy are attractive for applications in spintronic memory and logic devices, some already being implemented in MRAM …

Effect Of Oxidation Of Graphene On Agglomeration And The Mechanical Properties Of Thermosetting Resins, Matthew A. Reil

Electronic Theses and Dissertations

Thermosetting resins are used extensively worldwide in applications ranging from adhesives to structural components. However, these resins generally fail in a brittle fracture mode which is undesirable in most situations. Graphene (G) and its derivatives have been considered as additives to epoxy for material property enhancement and varied results have been reported in the literature. In this work, the effects of the oxidation of G to graphene oxide (GO) on polymer interactions and plate agglomeration were studied by classical molecular dynamics (MD). Results from those simulations concluded that agglomerates were likely present in all G-based nanocomposites. The effect of these …

Atom Probe Tomography Of Segregation At Grain Boundaries And Gas Bubbles In Neutron Irradiated U-10 Wt% Mo Fuel, Maalavan Arivu, Andrew Hoffman, Mukesh Bachhav, Assel Aitkaliyeva, Yaqiao Wu, Brandon Miller, Dennis Keiser, Jian Gan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

During Neutron Irradiation to Fission Densities > 5.2 X 1021 Fiss/cm3, Xe Agglomerates Forming Gas Bubbles of Varying Size within the U-Mo Fuel Matrix. Herein, Segregation of Fission Products to Xe Bubbles and Grain Boundaries (GB) Were Studied using Atom Probe Tomography (APT). Segregation Behavior Was Found to Vary among GBs, Small Bubbles (<10 >Nm), and Larger Bubbles (>10 Nm). Solid Fission Products Were Enriched at GBs and Larger Bubbles, But Not at Small Bubbles. a Denuded Zone Was Identified Adjacent to a > 10 Nm Xe Gas Bubble and a GB.

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

A Novel Method May Reveal Bulk Metallic Glass Compressive Ductility Trends In High Data Rate Nanoindentation, Jordan J. Sickle, Wesley H. Higgins, Wendelin Wright, George M. Pharr, Karin A. Dahmen

Faculty Journal Articles

Recent methods allow novel amorphous alloy compositions to be rapidly manufactured at small scale; however, obtaining materials properties such as compressive ductility from these smaller specimens has remained a challenge. Here, we suggest a potential high-throughput nanoindentation method that may be able to rapidly characterize the relative compressive ductility between these alloys based on their serration characteristics. The properties of emergent serrations, when interpreted in a simple micromechanical stress relaxation model, may order these materials by their compressive plastic strain to failure. These results are consistent with the ordering obtained from compressed specimens as well as with model simulations, suggesting …

Wild Joy: An Exploration In Queer Spatial Dynamics, Kipper Thomas Reinsmith

Masters Theses

What does it mean to feel represented in a space?

What does a trans space look like?

How can we queer our interior spaces?

Our world is crafted by the many designers that have come before us. These systems, products, and spaces are built upon assumptions of the bodies that will use and occupy them—namely cisgender, able-bodied, straight folks.

Designing and creating objects as a trans person is an act of radical nature. To take up space, to design for trans luxury, for the sake of beauty, for joy itself, feels counterintuitive to the narratives we’ve been served: that of …

Technocene, Vir Joseph Naidu

Masters Theses

Embodied human communication within the Anthropocene. Existing at the intersection of technology, and the body.

The design industry has developed technology that is, paradoxically, isolating. The exposure to a vast audience in the digital sphere has introduced new societal pressures, leading to a disconnection from our immediate surroundings, detached, and donning metaphorical masks. Technocene lives on the fringes of the discipline by blending conceptual thinking with practical application. Through curious, experimental artifacts, it prompts us to shed our masks and embrace vulnerability. Technocene endeavors to reimagine the human experience by acting as a discursive design project. It probes the boundaries …