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 …

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 …

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 …

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 …

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 …

Predicting Rheology Of Uv-Curable Nanoparticle Ink Components And Compositions For Inkjet Additive Manufacturing, Cameron D. Lutz

Master's Theses

Inkjet additive manufacturing is the next step toward ubiquitous manufacturing by enabling multi-material printing that can exhibit various mechanical, electronic, and thermal properties. These characteristics are realized in the careful formulation of the inks and their functional materials, but there are many constraints that need to be satisfied to allow optimal jetting performance and build quality when used in an inkjet 3-D printer. Previous research has addressed the desirable rheology characteristics to enable stable drop formation and how the metallic nanoparticles affect the viscosity of inks. The contending goals of increasing nanoparticle-loading to improve material deposition rates while trying to …

Photodegradation Of Microplastics Through Nanomaterials: Insights Into Photocatalysts Modification And Detailed Mechanisms, Yiting Xiao, Yang Tian, Wenbo Xu, Jun Zhu

Biological and Agricultural Engineering Faculty Publications and Presentations

Microplastics (MPs) pose a profound environmental challenge, impacting ecosystems and human health through mechanisms such as bioaccumulation and ecosystem contamination. While traditional water treatment methods can partially remove microplastics, their limitations highlight the need for innovative green approaches like photodegradation to ensure more effective and sustainable removal. This review explores the potential of nanomaterial-enhanced photocatalysts in addressing this issue. Utilizing their unique properties like large surface area and tunable bandgap, nanomaterials significantly improve degradation efficiency. Different strategies for photocatalyst modification to improve photocatalytic performance are thoroughly summarized, with a particular emphasis on element doping and heterojunction construction. Furthermore, this review …

In Situ And 2d And 3d In Silico Redox Cycling Studies For Design Optimization Of Coplanar Arrays Of Microband Electrodes In A 70 Μm × 100 Μm Electroactive Footprint, Miguel Angel Abrego Tello, Mahsa Lotfi Marchoubeh, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

Optimization of redox-cycling currents was performed by adjusting the height (sidewalls, h), width (w), and length (l) of band electrodes and their spacing (w_gap) in coplanar arrays restricted to a small-electroactive window of 70 × 100 μm. These arrays can function in μL-volumes for chemical analysis (e.g., in-vivo dopamine detection using probes). Experiments were conducted with an array of five electrodes (NE = 5), w = 4.3 μm, w_gap = 3.7 μm, h = 0.150 μm, and l = 99.2 μm. Reasons for …

Modeling Charging Current Dynamics At Microelectrodes And Their Interfaces With Electrolyte And Insulators With A Focus On Microfabricated Gold Microband Electrodes On An Su-8 Substrate, Miguel Angel Abrego Tello, Mahsa Lotfi Marchoubeh, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

The suitability of electrochemical methods for quantitative measurements at microdevices is influenced by the relatively large electrode-insulator interface-to-electrode area ratio, greatly impacting charging dynamics due to interactions among electrolyte, conductor material, and insulator layers. The resulting charging current can overwhelm the faradaic current from redox chemistry. The device studied here features a 70 μm × 100 μm electroactive window, hosts gold coplanar microband electrodes, and is insulated by SU-8, which serves as both overlayer and substrate. The overlayer defines the electroactive length and isolates the leads of the electrodes from the sample solution. Cyclic voltammetry in 0.10 M …

Settingsorder Article Reprints Open Accesseditor’S Choicearticle Exploring The Impact Of Spray Process Parameters On Graphite Coatings: Morphology, Thickness, And Tribological Properties, Adedoyin Abe, Josue A. Goss, Min Zou

Mechanical Engineering Faculty Publications and Presentations

This study explores, through a full factorial experimental design, the effects of graphite concentration and spray flow rate on the morphology, thickness, and tribological performance of graphite coatings for potential tribological applications. Coatings were applied to rough substrates using varying concentrations and flow rates, followed by analysis of their morphological characteristics, roughness, thickness, coefficient of friction (COF), and wear behavior. The results revealed distinct differences in the coating morphology based on flow rate, with low-flow-rate coatings exhibiting a porous structure and higher roughness, while high-flow-rate coatings displayed denser structures with lower roughness. A COF as low as 0.09 was achieved, …

Combinatorial Studies Of Noble Metal Catalysts For Carbon Utilization, Natalie Leong Page

Theses and Dissertations

Electrocatalysts demonstrate significant promise for sustainable processes like carbon capture and generating recycled carbon fuels which are needed to achieve net zero carbon emissions. However, the commercialization of these processes is limited by several factors, one of which is the high cost of catalysts. The discovery and development of cheaper alternatives has been difficult due to constraints in experimental methodologies, scalability limitations, and a lack of understanding of reaction mechanisms. Within this dissertation is the development of a novel scanning electrochemical system and its implementation for high-throughput data generation from combinatorially sputtered material libraries. Combinatorial Pd-Au alloys were investigated for …

A Computational Investigation Of Wood Selection For Acoustic Guitar, Jonah Osterhus

Senior Honors Theses

The acoustic guitar is a stringed instrument, often made of wood, that transduces vibrational energy of steel strings into coupled vibrations of the wood and acoustic pressure waves in the air. Variations in wood selection and instrument geometry have been shown to affect the timbre of the acoustic guitar. Computational methods were utilized to investigate the impact of material properties on acoustic performance. Sitka spruce was deemed the most suitable wood for guitar soundboards due to its acoustic characteristics, strength, and uniform aesthetic. Mahogany was deemed to be the best wood for the back and sides of the guitar body …

Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan

Journal of Materials Exploration and Findings

Metal matrix composite (MMC) with 7xxx aluminum matrix is potential for ballistic applications due to the combination of strength, toughness, and light weight. Previous study successfully produced aluminum-based composites with SiC particles which were able to stop type III bullet, however cracks remained on back of the plate. Therefore, in this research, SiC was replaced by zirconia (ZrO₂) due to its high fracture toughness. Ti-B grain refiner was added to further improve toughness through grain boundary strengthening mechanism. This research developed 5 vol.% ZrO₂ strengthened Al-10Zn-6Mg-2Si composite with addition of Al-5Ti-1B grain refiner produced through squeeze casting …

Integration Of The Ashby Technique And Pahl-Beitz Quantitative Ranking For Railway Axle Material Selection, Helya Chafshoh Nafisah, Jaka Fajar Fatriansyah, Siti Norasmah Surip

Journal of Materials Exploration and Findings

Railway axle serves as a vital connection between the train's wheels and its body. However, cyclic loading and high speed can induce fatigue in railway axle, which potentially leads to damage human safety. Therefore, it is important to find materials that have good mechanical properties with the lowest weight and cost. In this paper, a comprehensive method using Ashby chart has been performed to select candidate materials of railway axle. The methods begin with analyzing function by determining the problem, objective function, and constraints. After that, the results obtained are ranked using Pahl and Beitz quantitative weighting method. The results …

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …

Mechanical And Deformation Characteristics Of Piles In Coastal Soft Soil Areas Considering Softening Effect, Wang Fei, Yan Yu, Jiao Lidong, Shen Fengqi, Chen Lu, Liu Jianhua

Journal of China & Foreign Highway

In order to discuss the mechanical and deformation behavior of piles in coastal soft soil areas under horizontal load，the corresponding simplified mechanical model was established according to the loading characteristics of piles in coastal soft soil areas.Secondly，the softening effect of coastal soft soil was considered to modify the existing p-y curve model.On this basis，the differential equation of pile deflection in coastal soft soil areas was derived，and its internal force and displacement were solved by the transfer matrix method.A nonlinear calculation method of piles in coastal soft soil areas considering the softening effect was obtained.Finally，the influence of softening parameters，pile diameter，and elastic …