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A strategy for out-of-roundness damage wheels identification in railway vehicles based on sparse autoencoders

Railway engineering Science 2024年第4期32卷 421-443页

作者： Jorge Magalhães Tomás Jorge Rúben Silva António Guedes Diogo Ribeiro Andreia Meixedo Araliya Mosleh Cecília Vale Pedro Montenegro Alexandre Cury CONSTRUCT-LESE School of EngineeringPolytechnic of PortoPortoPortugal CONSTRUCT-LESE Faculty of EngineeringUniversity of PortoPortoPortugal Graduate Program in Civil Engineering Federal University of Juiz de ForaJuiz de ForaBrazil

Wayside monitoring is a promising cost-effective alternative to predict damage in the rolling stock. The main goal of this work is to present an unsupervised methodology to identify out-of-roundness(OOR) damage wheels, such as wheel flats and polygonal wheels. This automatic damage identification algorithm is based on the vertical acceleration evaluated on the rails using a virtual wayside monitoring system and involves the application of a two-step procedure. The first step aims to define a confidence boundary by using(healthy) measurements evaluated on the rail constituting a baseline. The second step of the procedure involves classifying damage of predefined scenarios with different levels of severities. The proposed procedure is based on a machine learning methodology and includes the following stages:(1) data collection,(2) damage-sensitive feature extraction from the acquired responses using a neural network model, i.e., the sparse autoencoder(SAE),(3) data fusion based on the Mahalanobis distance, and(4) unsupervised feature classification by implementing outlier and cluster analysis. This procedure considers baseline responses at different speeds and rail irregularities to train the SAE model. Then, the trained SAE is capable to reconstruct test responses(not trained) allowing to compute the accumulative difference between original and reconstructed signals. The results prove the efficiency of the proposed approach in identifying the two most common types of OOR in railway wheels.

关键词： OOR wheel damage Damage identification Sparse autoencoder Passenger trains Wayside condition monitoring

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The influence of plastic waste on the properties of lime-based mortars

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Frontiers of Structural and civil engineering 2025年第3期19卷 477-487页

作者： Vasiliki PACHTA Angeliki-Christina VEDINOGLOU Sofia FLEVARAKI Laboratory of Building Materials School of Civil EngineeringAristotle University of ThessalonikiThessaloniki 54124Greece Interdepartmental Program of Postgraduate Studies‘Protection Conservation and Restoration of Cultural Monuments’ Aristotle University of ThessalonikiThessaloniki 54124Greece

The increasing consumption of plastics, and the threat of environmental impact of their disposal, renders the management of their waste of interest. In the present study, an effort has been made to investigate the influence of waste polyvinyl chloride (PVC) and polypropylene (PP) of various origin in lime-based mortars, applied in the restoration of traditional structures. Nine mortar compositions (based on lime and natural pozzolan) were designed, manufactured and tested, in which natural aggregates were partially substituted by waste plastics (in proportions of 12.5% and 25% v/v of aggregates). According to the research results, shrinkage deformations were reduced in the short term in all modified compositions, porosity showed slight changes, while apparent specific gravity and capillary absorption index were decreased. Mechanical properties were enhanced in the case of the PVC and the lower PP flakes addition (12.5% v/v), while compressive strength was reduced around 5%–25% in the higher proportion (25% v/v). Generally, it could be asserted that the 12.5% v/v proportion of waste plastics offered benefit, and in particular PVC addition was beneficial in terms of physico-mechanical properties, rendering the exploitation of plastic waste in lime-based systems feasible.

关键词： plastic waste lime mortars pozzolan polypropylene polyvinyl chloride

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Left-turn phasing selection considering vehicle to vehicle and vehicle to pedestrian conflicts

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Journal of Traffic and Transportation engineering(English Edition) 2023年第1期10卷 58-69页

作者： Kakan C.Dey Md Tawhidur Rahman Subasish Das Amrit Manova Williams Wadsworth Department of Civil and Environmental Engineering West Virginia UniversityMorgantownWV 26506USA AECOM Technical Services Inc.PhoenixAZ 85020USA Ingram School of Engineering Texas State UniversitySan MarcosTX 78666USA Davenport Engineering CharlotteNC 28273USA

Left-turning vehicle movement at signalized intersections with permissive left-turn phases creates safety concerns due to the higher chance of conflict with opposing-through vehicles and *** this research,a simulation-based study was conducted to evaluate pedestrians’impact on traffic conflicts between left-turning vehicles and opposing-through vehicles(V-V conflicts)as well as traffic conflicts between left-turning vehicles and pedestrians(V-P conflicts)in the permissive left-turn phasing *** with different opposing-through volumes,left-turn volumes,number of opposing-through lanes,and pedestrian volumes were modeled in VISSIM,a traffic *** surrogate safety assessment model(SSAM)was used to estimate the number of V-V and VP *** effect of pedestrian presence on V-V and V-P conflicts was evaluated using simulation scenarios with and without pedestrian *** results revealed that pedestrian presence increased both V-V and V-P *** pedestrian presence increased the total number of traffic conflicts,permissive left-turn phasing processed fewer left-turn vehicles to maintain the same level of intersection safety with pedestrian presence compared to the no-pedestrian *** current left-turn phasing decision guidelines do not consider the impacts of pedestrian presence,this research quantified pedestrian-influenced and pedestrian-involved left-turn traffic conflicts to determine appropriate left-turn signal phasing decisions to ensure safe and efficient crossing of pedestrians and vehicles at signalized *** simulation-based study’s findings can be beneficial in the decision making of left-turn phasing selection as the before-after intersection safety performance analysis by collecting field data often resources intensive.

关键词： V-V conflicts V-P conflicts Left-turn phasing Pedestrian Warrants

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Application of text mining techniques to identify actual wrong-way driving (WWD) crashes in police reports

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International Journal of Transportation Science and Technology 2023年第4期12卷 1038-1051页

作者： Parisa Hosseini Seyedalireza Khoshsirat Mohammad Jalayer Subasish Das Huaguo Zhou Department of Civil and Environmental Engineering Center for Research and Education in Advanced Transportation Engineering Systems(CREATEs)Rowan University201 Mullica Hill RoadGlassboroNJ 08028USA Department of Computer&Information Sciences University of Delaware18 Amstel AveNewarkDE 19716USA Civil Engineering Program Ingram School of EngineeringTexas State UniversityRFM 5202601 University DriveSan MarcosTX 78666USA Harbert Center Department of Civil and Environmental EngineeringAuburn UniversityAuburnAL 36849USA

Wrong-way driving(WWD)has been a long-lasting issue for transportation agencies and law enforcement,since it causes pivotal threats to road *** being rare,crashes occurring due to WWD are more severe than other types of *** order to analyze WWD crashes,there is a need to obtain WWD incidents or crash ***,it is time-consuming to identify actual WWD crashes from potential WWD crashes in large crash *** often involves large man-hours to review hardcopy of crash narratives in the police ***,it may cause an overestimation or underestimation of WWD crash *** fill this gap,the present study,as the first-of-its-kind,aims at identifying actual WWD crashes from potential WWD crashes in police reports by using machine learning ***,Bidirectional Encoder Representations from Transformers(BERT)models have shown promising results in natural language *** this study,we implemented the BERT model as well as five conventional classification algorithms,including Naïve Bayes(NB),Support Vector Machine(SVM),Decision Tree(DT),Random Forest(RF),and Single Layer Perceptron(SLP)to classify crash report narratives as actual WWD and non-WWD ***-validation and different performance metrics were used to evaluate the performance of each classification *** indicated that the BERT model outperformed in identifying actual WWD crashes in comparison with other algorithms with an accuracy of 81.59%.The BERT classification algorithm can be implemented to reduce the time needed to identify actual WWD crashes from crash report narratives.

关键词： Wrong-Way Driving Crashes Crash Report Narratives Text Mining Text Classification

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Development of a Zero-Stress Temperature Prediction Model for Portland Cement Concrete Pavements

SSRN

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SSRN 2024年

作者： Yeon, Jung Heum Civil Engineering Program Ingram School of Engineering Texas State University San MarcosTX78666 United States

Zero-stress temperature (ZST) is a substantial parameter in the mechanistic-empirical pavement design guide (MEPDG) that significantly affects the behavior and performance of continuously reinforced concrete pavement (CRCP). The current model in the MEPDG for estimating ZST is overly simplistic, relying only on the monthly average temperature during construction and the cementitious content, which can lead to inaccuracies in predicting long-term performance. To address this issue, this study aimed to develop an advanced ZST prediction model for portland cement concrete (PCC) pavements through extensive numerical simulations and statistical analysis. Two-dimensional (2D) nonlinear finite element (FE) models were developed to accurately predict concrete temperature and stress, incorporating age-dependent material properties and dynamic environmental interactions. An extensive parametric study was conducted using these models, involving seven independent variables, which generated datasets for statistical modeling. Multivariate regression analysis was then performed, introducing a new characteristic value, the C-value, to statistically quantify ZST on the basis of the final set temperature and maximum concrete temperature. The regression analysis achieved an R2 value greater than 0.90 and a significance level below 0.01, indicating strong statistical confidence. Validation of the new model showed good agreement with the parametric analysis data. Comparisons with field test data revealed discrepancies of only 0.1 to 0.9°C between predicted and measured ZST values, significantly improving accuracy compared to the current MEPDG ZST model, which showed 3.9 to 13.9°C discrepancies. This new model enhances ZST prediction accuracy and contributes to improved PCC pavement performance. © 2024, The Authors. All rights reserved.

关键词： Portland cement

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Development of an Electrically Heated Sidewalk System for Enhanced Winter Pedestrian Safety

SSRN

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SSRN 2024年

作者： Mohapoo, Ramita Chakraborty, Rajesh Yeon, Jung Heum Civil Engineering Program Ingram School of Engineering Texas State University San MarcosTX78666 United States

This study aims to develop an electrically heated sidewalk system to efficiently clear ice and snow from pedestrian walkways, ensuring safety and minimizing environmental impact during winter. Concrete mixtures containing 2.2% carbon fibers (CFs) and 0.5% carbon nanotubes (CNTs) by cement weight were used to cast the electrically heated concrete side blocks. No.4 structural rebars served as electrodes to physically connect the side blocks and distribute electrical power to them. A laboratory-scale prototype, consisting of a 5 x 5 block array (750 mm x 750 mm), was constructed to evaluate the heating performance. The surface and internal temperatures were measured using an infrared camera and thermocouples, respectively, while consistently powering the prototype with a power supply. The blocks were connected in a parallel electrical configuration to operate the system at low voltage levels. Results indicated a surface temperature increase of 16–18°C over two hours with a power density ranging from 620–830 W/m2, which was sufficient for deicing pedestrian walkways. Additionally, a two-dimensional (2D) finite element (FE) analysis was conducted using commercial software to simulate the temperature rise, combining electromagnetic and thermal analyses. The experimental results closely matched the numerical simulations, demonstrating the effectiveness of the developed FE model in accurately reproducing the electrical heating behavior of the system. © 2024, The Authors. All rights reserved.

关键词： Thermocouples

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Elastic and Inelastic Input Energy Correlations: Effects of Damping, Pulse Type, and Significant Duration 1

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2nd International Workshop on Energy-Based Seismic engineering, IWEBSE 2023

作者： Çalım, Furkan Güllü, Ahmet Yüksel, Ercan Faculty of Civil Engineering Istanbul Technical University Istanbul Turkey Ingram School of Engineering Texas State University San MarcosTX78666 United States

ISBN: (数字)9783031365621

ISBN: (纸本)9783031365614

In the seismic analysis and design of the structures, the energy-based approach has been considered a sought-after alternative to conventional design approaches in recent years. It accounts for the pulse type, frequency content, and duration-related cumulative damage potential of an earthquake. Precise computation of seismic input energy imparted into the structure during a seismic action is decisive in reaching a comprehensive energy-based seismic design method. Hence, based on the modal contributions, a methodology to determine the seismic input energy demands of multi-degree-of-freedom (MDOF) frames has been proposed. This paper evaluated the method through nonlinear response history analyses (NRHA) of four benchmark MDOF frames with three, six, nine, and twenty stories. The effects of the pulse type and significant duration of the ground motions, and the system’s damping characteristics on the elastic and inelastic input energy correlations were investigated. Whereas the correlation was not significantly affected by the significant duration of the earthquake record or the period of the structure, better correlations were detected for the structural systems with a 5% damping ratio under non-pulse-like ground motion records. The correlation between the elastic and inelastic seismic input energies was nearly 98%, with a maximum mean difference of 18.9% for the non-pulse-like ground motion records. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Damping

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Study of Hybrid Steel Fibers Effects on the Workability and Compressive Properties of Non-proprietary UHPC 3rd

Study of Hybrid Steel Fibers Effects on the Workability and ...

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3rd International Conference on Sustainable civil engineering and Architecture, ICSCEA 2023

作者： Zhang, Ye Ogawa, Yuko Goegre, Riya Catherine Kawai, Kenji Civil and Environmental Engineering Program Graduate School of Advanced Science and Engineering Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima Japan

ISBN: (纸本)9789819974337

Non-proprietary ultra-high-performance concrete (UHPC) is renowned for excellent mechanical properties, especially high compressive strength which is generally above 150 MPa. Despite the high compressive strength, the failure mode of non-proprietary UHPC under axial loading is sudden, brittle, and explosive. The undesired compression failure mode is not ideal for structure design and undermines the engineering value of non-proprietary UHPC. This research targets to convert the compression failure mode of non-proprietary UHPC from brittle to ductile with hybrid steel fiber reinforcement and select the most effective reinforcing proportion. In this research, a ground granulated blast-furnace slag (GGBS) based non-proprietary UHPC mix is reinforced with five combinations of two steel fiber types with straight ends. The lengths of the two steel fibers are 6.5 mm and 13 mm. The total volume fraction of steel fibers is 2%. The 28-day compressive strengths and the failure modes of the reinforced samples are compared to select a hybrid steel fiber combination that transforms the failure mode of non-proprietary UHPC and strengthens the compression performance most effectively. The experiment results demonstrate that: (1) with steel fibers presented, non-proprietary UHPC is capable of continuously taking compressive load after matrix cracks;(2) instead of explosive brittle failure mode, fiber reinforced non-proprietary UHPC fails in a ductile behavior under axial compression load and the samples stay in integrity;(3) hybrid steel fiber reinforcement is more effective than single type steel fiber reinforcement in improving the compression performance of non-proprietary UHPC. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Compressive strength

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Field Implementation of Electrically Heated Precast Concrete Panels: A Case Study

SSRN

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SSRN 2024年

作者： Yeon, Jung Heum Chakraborty, Rajesh Civil Engineering Program Ingram School of Engineering Texas State University San MarcosTX78666 United States

An electrically heated precast concrete panel system was developed as an efficient and sustainable solution for snow and ice removal on roadways, ensuring enhanced driver safety during winter storms and snowy conditions. The system comprises three core elements: (i) electrically conductive cement-based heating elements incorporating carbon fibers and carbon nanotubes, (ii) stainless-steel bars as electrodes to distribute electric current, and (iii) electrical power control panels tailored to meet the anticipated power demand for achieving the target heating performance—a 20°C surface temperature increase within 2 hours. In November 2023, this innovative system was implemented in a construction project in Seoul, South Korea, where a 20-meter-long single-lane asphalt pavement section at a bus stop was replaced with precast concrete panels designed to withstand heavy bus traffic loads. Prior to field implementation, the heating and deicing performance of the developed system was evaluated in a full-scale climatic chamber at the Center for Climatic Environment Real-Scale Testing (CERT) of the Korea Conformity Laboratories (KCL), where realistic snowy scenarios could be simulated and reproduced. Both full-scale laboratory and field evaluations showed satisfactory heating performance, achieving a 20°C surface temperature increase within 2 hours with a power density of 450–500 W/m2. This indicates the promising potential of the developed deicing technology in winter road maintenance. © 2024, The Authors. All rights reserved.

关键词： Asphalt pavements

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Frost Damage Resistance of Portland Blast-Furnace Slag Cement Concrete Cured Internally by Using Roof-Tile Waste Aggregate 2nd

Frost Damage Resistance of Portland Blast-Furnace Slag Cemen...

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2nd International Conference on Sustainable civil engineering and Architecture, ICSCEA 2021

作者： Kirimoto, Taishi Ogawa, Yuko Kawai, Kenji Civil and Environmental Engineering Program Graduate School of Advanced Science and Engineering Hiroshima University Higashihiroshima City Japan

ISBN: (纸本)9789811933028

The purpose of this study was to clarify the relationship between the internal curing effect of roof-tile waste aggregate and frost damage resistance, and to investigate the effects of the replacement ratio of roof-tile waste aggregate as well as curing conditions on the frost damage resistance of concrete. Five types of concrete using Portland blast-furnace slag cement were prepared with a water-to-cement ratio of 0.50 and different replacement ratios of roof-tile waste coarse aggregate (20% and 50% by volume) and roof-tile waste fine aggregate (23% and 58% by volume). Concrete specimens were cured at 20 °C under sealed condition for 3, 7, or 28 days, and they were subsequently exposed to air at 20 °C and 60%R.H. until the age of 28 days. Then, the tests for resistance of concrete to freezing and thawing were carried out for 300 cycles in water, and the relative dynamic modulus of elasticity as well as the mass loss was assessed at the designated periods. As a result, it was found that sufficient frost damage resistance could be secured when the replacement ratio of roof-tile waste aggregate was approximately 20% by volume, and the improvement in frost damage resistance was observed especially when fine aggregate was replaced. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Slags

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