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A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan 2019 Clemson University

A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan

Amir Safiey

Steel corrosion is mainly at fault for the trend of deterioration among U.S. infrastructure—namely, bridges, pipelines, and wharves. Reinforced concrete (RC) is used as the primary construction material worldwide. Reinforcement corrosion can significantly impair mechanical properties of RC members, including shear and bending capacities. In the past decades, several attempts have been made to investigate the impacts of corrosion on the mechanical behavior of RC members. It can be observed that the number of research programs conducted on this topic has rapidly increased in recent years. Therefore, there is a need in the body of knowledge to encapsulate ...


Investigation Of Corrosion Effects On Bond-Slip And Tensile Strength Of Reinforced Concrete Members, M. A. Shayanfar, Amir Safiey, M. Ghalehnovi 2019 Iran University of Technology

Investigation Of Corrosion Effects On Bond-Slip And Tensile Strength Of Reinforced Concrete Members, M. A. Shayanfar, Amir Safiey, M. Ghalehnovi

Amir Safiey

The corrosion effect on tensile strength of RC members is very important to region with high corrosion conditions. In this article a study on finding bond behaviour, crack pattern, crack spacing, and tensile strength of RC members is presented. For this purpose a comprehensive experimental program including reinforced concrete cylanders with different concrete covers and reinforcement ratios under various corrosion rates is conducted. The specimens are located in large tub containing water and salt (5% salt solution) with a devich for accelerated corrosion production. For each specimen, the variation of total tensile strength versus its average strain is plotted and ...


Hypoelastic Modeling Of Reinforced Concrete Walls, Mohsen A. Shayanfar, Amir Safiey 2019 Iran University of Science and Technology

Hypoelastic Modeling Of Reinforced Concrete Walls, Mohsen A. Shayanfar, Amir Safiey

Amir Safiey

This paper presents a new hypoelasticity model which was implemented in a nonlinear finite element formulation to analyze reinforced concrete (RC) structures. The model includes a new hypoelasticity constitutive relationship utilizing the rotation of material axis through successive iterations. The model can account for high nonlinearity of the stress-strain behavior of the concrete in the pre-peak regime, the softening behavior of the concrete in the post-peak regime and the irrecoverable volume dilatation at high levels of compressive load. This research introduces the modified version of the common application orthotropic stress-strain relation developed by Darwin and Pecknold. It is endeavored not ...


Fiber Element-Based Nonlinear Analysis Of Concrete Bridge Piers With Consideration Of Permanent Displacement, Mokhtar Ansari, Farhad Daneshjoo, Amir Safiey, Naser Safaeian Hamzehkolaei, Maryam Sorkhou 2019 Bozorgmehr University of Qaenat

Fiber Element-Based Nonlinear Analysis Of Concrete Bridge Piers With Consideration Of Permanent Displacement, Mokhtar Ansari, Farhad Daneshjoo, Amir Safiey, Naser Safaeian Hamzehkolaei, Maryam Sorkhou

Amir Safiey

Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near- fault ground shaking. In this research, the influence ...


Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey 2019 Iran University of Science and Technology

Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey

Amir Safiey

The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means ...


Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei 2019 Clemson University

Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei

AMIR SAFIEY

The concept of performance-based earthquake engineering has gained significant attentions in both the research and engineering communities. The development of a performance-based seismic loss assessment framework, known as the FEMA P-58 method, allows one to estimate the potential financial losses of a building using performance-based engineering method. This research employs a seismic loss estimation framework derived using the P-58 method to estimate the monetary loss of a mid-rise wood-frame hotel building which is assumed to be located in Napa Valley, California. A 3D structural model representative of the dynamic behavior of the wood-frame hotel was created and subjected to Incremental ...


Evaluation Of The Cracking Performance Of Geogrid-Reinforced Hot-Mix Asphalt For Airfield Applications, Daniel Offenbacker 2019 Rowan University

Evaluation Of The Cracking Performance Of Geogrid-Reinforced Hot-Mix Asphalt For Airfield Applications, Daniel Offenbacker

Theses and Dissertations

The objective of this study was to evaluate the fatigue cracking performance of geogrid-reinforced Hot-Mix Asphalt (HMA) for use in airfield runways. An airfield HMA mixture with four different geogrid types were selected for this study. The geogrids varied in tensile strength, coating type, opening size, thickness, and fiber material. Several different laboratory performance tests were conducted (Dynamic Complex Modulus, DCM, Overlay Test, OT, and Indirect Tensile Strength, ITS) and the fatigue and/or cracking performance was evaluated. Additionally, different approaches were adopted or developed for the modeling of geogrids in HMA using Finite Element Modeling (FEM). Finally, a Life-Cycle ...


Quantifying Thermal Refugia Connectivity By Combining Temperature Modeling, Distributed Temperature Sensing, And Thermal Infrared Imaging, Jessica R. Dzara, Bethany T. Neilson, Sarah E. Null 2019 Utah State University

Quantifying Thermal Refugia Connectivity By Combining Temperature Modeling, Distributed Temperature Sensing, And Thermal Infrared Imaging, Jessica R. Dzara, Bethany T. Neilson, Sarah E. Null

Civil and Environmental Engineering Faculty Publications

Watershed-scale stream temperature models are often one-dimensional because they require fewer data and are more computationally efficient than two- or three-dimensional models. However, one-dimensional models assume completely mixed reaches and ignore small-scale spatial temperature variability, which may create temperature barriers or refugia for cold-water aquatic species. Fine spatial- and temporal-resolution stream temperature monitoring provides information to identify river features with increased thermal variability. We used distributed temperature sensing (DTS) to observe small-scale stream temperature variability, measured as a temperature range through space and time, within two 400 m reaches in summer 2015 in Nevada's East Walker and main stem ...


Oxytree Pruned Biomass Torrefaction: Mathematical Models Of The Influence Of Temperature And Residence Time On Fuel Properties Improvement, Kacper Świechowski, Marek Liszewski, Przemysław Bąbelewski, Jacek A. Koziel, Andrzej Białowiec 2019 Wrocław University of Environmental and Life Sciences

Oxytree Pruned Biomass Torrefaction: Mathematical Models Of The Influence Of Temperature And Residence Time On Fuel Properties Improvement, Kacper Świechowski, Marek Liszewski, Przemysław Bąbelewski, Jacek A. Koziel, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

Biowaste generated in the process of Oxytree cultivation and logging represents a potential source of energy. Torrefaction (a.k.a. low-temperature pyrolysis) is one of the methods proposed for the valorization of woody biomass. Still, energy is required for the torrefaction process during which the raw biomass becomes torrefied biomass with fuel properties similar to those of lignite coal. In this work, models describing the influence of torrefaction temperature and residence time on the resulting fuel properties (mass and energy yields, energy densification ratio, organic matter and ash content, combustible parts, lower and higher heating values, CHONS content, H:C ...


Analysis Of Disengagements In Semi-Autonomous Vehicles: Drivers’ Takeover Performance And Operational Implications, Francesca M. Favaro, Sky Eurich, Syeda Rizvi, Shivangi Agarwal, Sumaid Mahmood, Nazanin Nader 2019 San Jose State University

Analysis Of Disengagements In Semi-Autonomous Vehicles: Drivers’ Takeover Performance And Operational Implications, Francesca M. Favaro, Sky Eurich, Syeda Rizvi, Shivangi Agarwal, Sumaid Mahmood, Nazanin Nader

Francesca M. Favarò

This report analyzes the reactions of human drivers placed in simulated Autonomous Technology disengagement scenarios. The study was executed in a human-in-the-loop setting, within a high-fidelity integrated car simulator capable of handling both manual and autonomous driving. A population of 40 individuals was tested, with metrics for control takeover quantification given by: i) response times (considering inputs of steering, throttle, and braking); ii) vehicle drift from the lane centerline after takeover as well as overall (integral) drift over an S-turn curve compared to a baseline obtained in manual driving; and iii) accuracy metrics to quantify human factors associated with the ...


Transportation Safety Performance Of Us Bus Transit Agencies And Population Density: A Cross-Sectional Analysis (2008-2014), Ilker Karaca, Peter T. Savolainen 2019 Iowa State University

Transportation Safety Performance Of Us Bus Transit Agencies And Population Density: A Cross-Sectional Analysis (2008-2014), Ilker Karaca, Peter T. Savolainen

Ilker Karaca

The paper examines the transportation safety performance of transit agencies providing public bus service in the US by using data from the National Transit Database (NTD)

Uses NTD data for a seven-year period from 2008 to 2014 • 3,853 observations for 651 public transportation agencies in 50 states

Seven types of bus transit fatalities and injuries (including passengers, operators, pedestrians, bicyclists)

Main explanatory variable: urban density obtained from the US Census figures

Other explanatory variables: total agency revenue miles, unlinked passenger trips, agency fleet size, and urban population


Nchrp Synthesis 499: Alternate Design/Alternate Bid Process For Pavement-Type Selection. A Synthesis Of Highway Practice, Douglas D. Gransberg, Ashley F. Buss, Ilker Karaca, Michael C. Loulakis 2019 Iowa State University

Nchrp Synthesis 499: Alternate Design/Alternate Bid Process For Pavement-Type Selection. A Synthesis Of Highway Practice, Douglas D. Gransberg, Ashley F. Buss, Ilker Karaca, Michael C. Loulakis

Ilker Karaca

Highway administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem. There is information on nearly every subject of concern to highway administrators and engineers. Much of it derives from research ...


Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Bob Wu, Vadym Mochalin 2019 Missouri University of Science and Technology

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Bob Wu, Vadym Mochalin

Vadym Mochalin

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti3C2Tx and Ti2CTx) with a SiO2 coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account surface ...


Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu 2019 Clemson University

Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu

Amir Safiey

The seismic vulnerability functions for portfolio-level loss estimation are typically developed for general classes of buildings which may not be suitable to assess building-specific risks. Performance-based earthquake engineering (PBEE) provides the means to conduct building-specific seismic risk assessments. However, such assessments often rely on computationally-intensive analytical frameworks such as incremental dynamics analysis (IDA) which poses a challenge for many types of risk assessment projects. To expand its accessibility, FEMA P-58 outlines a simplified method to predict the nonlinear responses of buildings in which the scope is limited to lower levels of inter-story drifts (less than 4%). This limitation restricts its ...


Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg 2019 Clemson University

Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg

Amir Safiey

The probability that a building is sanctioned to demolition following an earthquake depends on several geotechnical, structural, strategic and financial decision variables. This paper explores the literature on post-earthquake reparability assessment of buildings focusing on structural characteristics and evaluates their approaches for four midrise code-compliant structural systems, namely, steel moment frame, reinforced concrete moment frame, light frame wood, and steel braced frame. The structural responses are estimated using incremental dynamics analysis (IDA) in accordance with FEMA P-695 provisions and the IDA results are relayed to a building-specific loss assessment framework to estimate their seismic vulnerability in terms of monetary losses ...


Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu 2019 Clemson University

Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu

Amir Safiey

Damage to contents and nonstructural components is often the main driver of property losses against smaller earthquakes as evidenced by empirical evidence from past events. In the 2014 South Napa earthquake in California, for example, 56% of the affected buildings reported content damage. The primary modes of content damage include sliding, rocking, and overturning. The FEMA P-58 document provides seismic fragility functions for sliding and overturning of unanchored block content types, but no data is provided for anchored components. The ASCE/SEI 7-16 provides stability guidelines for different types of nonstructural components, but falls short of providing recommendations for the ...


Analytical Content Vulnerability Assessment Methodology For Earthquake Catastrophe Models, Keivan Rokneddin, Amir Safiey, Mohammad Javanbarg, Vijay Manghnani, Weichiang Pang 2019 AIG

Analytical Content Vulnerability Assessment Methodology For Earthquake Catastrophe Models, Keivan Rokneddin, Amir Safiey, Mohammad Javanbarg, Vijay Manghnani, Weichiang Pang

Amir Safiey

The scarcity of detailed claims data for building contents (Coverage C) from historical earthquake events poses a significant challenge for property insurance catastrophe models to reliably estimate the losses associated to building contents. To develop content vulnerability functions empirically, one would need to have access to data from a multitude of historical events; however, loss disaggregation by coverage is rarely reported even when claims data become available from recent significant events such as Maule (2010) and Tohoku (2011). While damage to the building structure (Coverage A) can be estimated analytically using simulation-based fragility functions to amend sparse historical observations, the ...


Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei 2019 Clemson University

Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei

Amir Safiey

The concept of performance-based earthquake engineering has gained significant attentions in both the research and engineering communities. The development of a performance-based seismic loss assessment framework, known as the FEMA P-58 method, allows one to estimate the potential financial losses of a building using performance-based engineering method. This research employs a seismic loss estimation framework derived using the P-58 method to estimate the monetary loss of a mid-rise wood-frame hotel building which is assumed to be located in Napa Valley, California. A 3D structural model representative of the dynamic behavior of the wood-frame hotel was created and subjected to Incremental ...


Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Bob Wu, Vadym Mochalin 2019 Missouri University of Science and Technology

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Bob Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti3C2Tx and Ti2CTx) with a SiO2 coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account surface ...


Features Of Designing The Architecture Of Intelligent Transport Systems, Jaffar Daeibal, Vyacheslav Lapshin, Dmitry Elkin, Sergey A. Kucherov 2019 Southern Federal University

Features Of Designing The Architecture Of Intelligent Transport Systems, Jaffar Daeibal, Vyacheslav Lapshin, Dmitry Elkin, Sergey A. Kucherov

Karbala International Journal of Modern Science

In the global experience, intelligent transport systems (ITS) are recognized as a general transport ideology for integrating the achievements of telematics in all types of transport activities to solve economic and social problems: reducing accidents, improving the efficiency of public transport and cargo transportation, ensuring overall transport security, and improving environmental performance. Considering the design features of the intelligent transport system (ITS), there is a need to develop requirements for the functional and physical architecture as the main part of the ITS development. The creation of functional and physical architecture touches upon issues such as: the scheme of interaction between ...


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