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Full-Text Articles in Engineering

Test Standard For Determining The Fastener-Sheathing Local Translational Stiffness Of Sheathed Cold-Formed Steel Assemblies, 2017 Edition, American Iron And Steel Institute Dec 2016

Test Standard For Determining The Fastener-Sheathing Local Translational Stiffness Of Sheathed Cold-Formed Steel Assemblies, 2017 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


Test Standard For Determining The Fastener-Sheathing Rotational Stiffness Of Sheathed Cold-Formed Steel Assemblies, 2017 Edition, American Iron And Steel Institute Dec 2016

Test Standard For Determining The Fastener-Sheathing Rotational Stiffness Of Sheathed Cold-Formed Steel Assemblies, 2017 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady Dec 2016

Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …


Smart Rock Technology For Real-Time Monitoring Of Bridge Scour And Riprap Effectiveness -- Design Guidelines And Visualization Tools, Genda Chen, Yan Tang, Yizheng Chen, Zhaochao Li, Chuanrui Guo, Liang Fan, Yi Bao, Xiuyan Hu, Matthew Klegseth Dec 2016

Smart Rock Technology For Real-Time Monitoring Of Bridge Scour And Riprap Effectiveness -- Design Guidelines And Visualization Tools, Genda Chen, Yan Tang, Yizheng Chen, Zhaochao Li, Chuanrui Guo, Liang Fan, Yi Bao, Xiuyan Hu, Matthew Klegseth

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to further develop and demonstrate the recently-proposed smart rock technology for scour depth and protection effectiveness monitoring. A smart rock is one or two stacked magnets encased in a concrete sphere with a specially-designed rotational mechanism. Design guidelines, rotational mechanisms, remote measurement tools and localization algorithms of smart rocks were developed and validated at three bridge sites. The effect of steel reinforcement in bridge piers/deck on the orientation of gravity-controlled magnets was negligible. The localization accuracy with a single smart rock met a general requirement of less than 0.5 m in engineering applications. The spherical smart rock …


North American Standard For The Design Of Profiled Steel Diaphragm Panels, 2016 Edition, American Iron And Steel Institute Oct 2016

North American Standard For The Design Of Profiled Steel Diaphragm Panels, 2016 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


North American Specification For The Design Of Cold-Formed Steel Structural Members, 2016 Edition, American Iron And Steel Institute Oct 2016

North American Specification For The Design Of Cold-Formed Steel Structural Members, 2016 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


Direct Strength Prediction Of Cold-Formed Steel Beam-Columns, American Iron And Steel Institute Oct 2016

Direct Strength Prediction Of Cold-Formed Steel Beam-Columns, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The Direct Strength Method (DSM) of cold-formed steel member design employs local, distortional, and global cross-section elastic buckling analysis with empirically derived “direct” expressions to predict member strength. DSM is an accepted design method in national design specifications (e.g., AISI-S100-16) and enables a unified, robust, and flexible design approach. However, for beam-columns DSM in current design specifications employs simplified linear interaction expressions based on combining the isolated axial and bending elastic buckling and strength response. Today, local, distortional, and global elastic buckling under any combination of axial load and bending moments may be found using elastic buckling analysis tools such …


Theoretical Study Of Two States Reactivity Of No Activation On Iron Atom, Xiaoman Wang, Yaxin Su, Wenyu Liao, Wenyi Deng Aug 2016

Theoretical Study Of Two States Reactivity Of No Activation On Iron Atom, Xiaoman Wang, Yaxin Su, Wenyu Liao, Wenyi Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The mechanism of Fe+NO was calculated by the Density Functional Theory (DFT) with the B3LYP methods combined with the 6-311+G (d, p) basis set. The geometry of reactants, transition states, intermediates and products of two reaction systems were completely optimized, and all the transition states were verified by the vibration analysis and intrinsic reaction coordinate (IRC) calculations. The "Two State Reactivity (TSR)" was used to analyze the reaction mechanisms; Results showed that the reaction system preferentially involves low-spin state entrance channel and the high-spin state exit channel. In the reaction channel, the crossing point appears, which would effectively reduce the …


Characterization Of Cfs Framed Diaphragm Behavior, American Iron And Steel Institute Aug 2016

Characterization Of Cfs Framed Diaphragm Behavior, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

Knowledge of the in-plane response to loading of cold-formed steel (CFS) framed diaphragm structures is essential for seismic and wind design. The information available specific to diaphragm design in the North American CFS design standards (AISI S240 & S400) is based on limited experimental work and the extrapolation of design methods developed for the wood industry. To address this shortcoming a test-based research project was performed in the Jamieson Structures Laboratory at McGill University focusing on the characterization of the behaviour under in-plane loading of CFS framed - wood sheathed diaphragms. This research was a complementary study to a research …


Phytovolatilization Of Organic Contaminants, Matt Limmer, Joel Gerard Burken Jul 2016

Phytovolatilization Of Organic Contaminants, Matt Limmer, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Plants can interact with a variety of organic compounds, and thereby affect the fate and transport of many environmental contaminants. Volatile organic compounds may be volatilized from stems or leaves (direct phytovolatilization) or from soil due to plant root activities (indirect phytovolatilization). Fluxes of contaminants volatilizing from plants are important across scales ranging from local contaminant spills to global fluxes of methane emanating from ecosystems biochemically reducing organic carbon. In this article past studies are reviewed to clearly differentiate between direct- and indirect-phytovolatilization and we discuss the plant physiology driving phytovolatilization in different ecosystems. Current measurement techniques are also described, …


Ccfss Special Edition Technical Bulletin Summer 2016, Wei-Wen Yu Center For Cold-Formed Steel Structures Jun 2016

Ccfss Special Edition Technical Bulletin Summer 2016, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.


Design Of Magnesium Phosphate Cement Based Composite For High Performance Bipolar Plate Of Fuel Cells, Wenbin Hao, Hongyan Ma, Zeyu Lu, Guoxing Sun, Zongjin Li Jun 2016

Design Of Magnesium Phosphate Cement Based Composite For High Performance Bipolar Plate Of Fuel Cells, Wenbin Hao, Hongyan Ma, Zeyu Lu, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on a magnesium phosphate cement (MPC) based composite as the construction material for high performance bipolar plates of fuel cells. MPC with partial replacement of fly ash was employed as the binding matrix. Some carbon-based materials, such as graphite, carbon black, carbon fiber, and multi-walled carbon nanotubes were used to construct the conductive phase. A simple hot-press process was applied to produce the composite. The formula and the structure of the composite was modified and adjusted to optimize the properties of the composite to meet the US DOE 2015 technical targets, including …


Temperature And Strain Measurements With Fiber Optic Sensors For Steel Beams Subjected To Fire, Yi Bao, Yizheng Chen, Matthew S. Hoehler, Christopher M. Smith, Matthew F. Bundy, Genda Chen Jun 2016

Temperature And Strain Measurements With Fiber Optic Sensors For Steel Beams Subjected To Fire, Yi Bao, Yizheng Chen, Matthew S. Hoehler, Christopher M. Smith, Matthew F. Bundy, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents measurements of high temperatures using a Brillouin scattering based fiber optic sensor and large strains using an extrinsic Fabry-Perot interferometric sensor for assessing the thermo-mechanical behaviors of simply supported steel beams subjected to combined thermal and mechanical loading. The distributed fiber optic sensor captures detailed, non- uniform temperature distributions that are compared with thermocouple measurements resulting in an average relative difference of less than 5 % at 95 % confidence level. The extrinsic Fabry- Perot interferometric sensor captures large strains at temperatures above 1000 C. The strain results measured from the distributed fiber optic sensors and extrinsic …


Shear Behavior Of High-Strength Self-Consolidating Concrete In Nebraska University Bridge Girders, Alex Griffin, John J. Myers May 2016

Shear Behavior Of High-Strength Self-Consolidating Concrete In Nebraska University Bridge Girders, Alex Griffin, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current reinforced and prestressed concrete design equations were developed for conventional concrete elements. Self-consolidating concrete (SCC) typically contains a lower coarse aggregate content and size than conventional concrete, which potentially hinders the aggregate interlock contribution to a concrete's shear strength. Thus, shear design equations must be verified with SCC mixtures. Two full-scale precast, prestressed concrete Nebraska University girders were tested to assess the shear behavior of high-strength SCC. Both girders were designed to permit two tests on each girder, both with and without shear reinforcement. Ultimate shear loads and crack patterns were documented and compared with code estimates, finite element …


Environmental Engineering Laboratory Development To Promote Active And Hands-On Learning, Sanjay Tewari Apr 2016

Environmental Engineering Laboratory Development To Promote Active And Hands-On Learning, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This extended abstract details one instructor’s experience in incorporating hands-on laboratory portion in a junior level civil engineering class, Environmental Engineering. The objective of the change was to help students become more involved and aware of their own learning through active participation so that they can relate to course contents in a better way. The author sought to achieve this through a laboratory structure that 1) required students to reflect on certain topics and device a do-it-yourself experiment to measure certain parameters and 2) provided a level of autonomy by allowing them to choose to work alone or in small …


Traffic Study Using A Video Camera And An Image Processing Software Lessons Learned, Sanjay Tewari, Nazimuddin Wasiuddin, Marissa K. Orr Apr 2016

Traffic Study Using A Video Camera And An Image Processing Software Lessons Learned, Sanjay Tewari, Nazimuddin Wasiuddin, Marissa K. Orr

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Highway Engineering I – CVEN332, is a junior-level course in civil engineering that covers primarily traffic engineering and transportation planning. Traffic engineering topics include isolated intersection signal timing design, intersection capacity analysis and freeway capacity analysis. In fall 2015, students collected real life and local field data in two design modules and used a traffic camera compatible with the video processing software in one design module. The objective of this study is to assess if the usage of local, real life field data and introduction of a traffic camera have any impact on increasing learning, increasing feeling of preparedness and …


Evaluation Of Carbonation Resistance Of Paint Coated Concrete For Buildings, Tommy Y. Lo, Wenyu Liao, C. K. Wong, Waiching Tang Mar 2016

Evaluation Of Carbonation Resistance Of Paint Coated Concrete For Buildings, Tommy Y. Lo, Wenyu Liao, C. K. Wong, Waiching Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When evaluating the carbonation resistance of paint coated concrete, the effects of both the strength grade and the curing conditions (standard curing and accelerated curing) of concrete substrate on carbonation resistance of paint coated concrete were investigated. The concept of the carbonation suppression ratio of paint was presented for evaluation of the anti-carbonation performance of the two types of paints (exterior and interior paints) when applied to a reference concrete substrate. The test results showed a good linear relationship between the carbonation depths of the paint coated concrete and the square root of exposure times. Concrete with higher strength grade …


Numerical Simulation Of Shock Response And Dynamic Fracture Of A Concrete Dam Subjected To Impact Load, Lu Lu, Xin Li, Jing Zhou, Genda Chen, Dong Yun Mar 2016

Numerical Simulation Of Shock Response And Dynamic Fracture Of A Concrete Dam Subjected To Impact Load, Lu Lu, Xin Li, Jing Zhou, Genda Chen, Dong Yun

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The shock response and dynamic fracture of concrete gravity dams under impact load are the key problems to evaluate the antiknock safety of the dam. This study aims at understanding the effects of impact shock on the elastic response and dynamic fracture of concrete gravity dams. Firstly, this paper uses acceleration records of a concrete gravity dam under impact to establish the correct way to determine the concrete gravity dam of the fundamental frequency and present cut sheets multi-degree-of-freedom dynamic modeling. Under strong impact loading, the constitutive relation of concrete gravity dam and the highest frequency of the impact are …


Resistance Of Arc Spot Welds -- Update To Provisions, American Iron And Steel Institute Feb 2016

Resistance Of Arc Spot Welds -- Update To Provisions, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The provisions of the AISI S100-12 standard for strength of arc spot welds loaded in shear and tension have not been revised since the 1999 standard. Since then, four new research studies have created and tested arc spot welded connections, expanding the database of available tests. Therefore, a reconsideration of both the resistance equations and the resistance and safety factors using the enlarged data base was undertaken. This study performed a comprehensive analysis of the entire arc spot weld data base, where 450 specimens were categorized by their respective failure modes to assess current AISI S100-12 resistance equations. Performance of …


Resistance Of Arc Spot Welds – Update To Provisions, B. Paige Blackburn, Thomas Sputo, Cevyn Meyer Feb 2016

Resistance Of Arc Spot Welds – Update To Provisions, B. Paige Blackburn, Thomas Sputo, Cevyn Meyer

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The American Iron and Steel Institute (AISI) Standards Council selected this project as one of four winning research proposals for its 2015 Small Project Fellowship Program. Project selections were based on several factors, including the potential for long-term impact on the industry; steel industry engagement and co-funding; and results for the AISI standards development committee, the student, and the academic institution. The objective of this project was to evaluate the provisions for determining the strength of arc spot welds in light of recent research studies. It is anticipated that the results of this study will impact the provisions in future …


A Spatial-Dynamical Framework For Evaluation Of Satellite Rainfall Products For Flood Prediction, Felipe Quintero, Witold F. Krajewski, Ricardo Mantilla, Scott Small, Bong Chul Seo Jan 2016

A Spatial-Dynamical Framework For Evaluation Of Satellite Rainfall Products For Flood Prediction, Felipe Quintero, Witold F. Krajewski, Ricardo Mantilla, Scott Small, Bong Chul Seo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rainfall maps that are derived from satellite observations provide hydrologists with an unprecedented opportunity to forecast floods globally. However, the limitation of using these precipitation estimates with respect to producing reliable flood forecasts at multiple scales are not well understood. To address the scientific and practical question of applicability of space-based rainfall products for global flood forecasting, a data evaluation framework is developed that allows tracking the rainfall effects in space and time across scales in the river network. This provides insights on the effects of rainfall product resolution and uncertainty. Obtaining such insights is not possible when the hydrologic …


No Reduction By Propane Over Monolithic Cordierite-Based Fe/Al2o3 Catalyst: Reaction Mechanism And Effect Of H2o/So2, Hao Zhou, Yaxin Su, Wenyu Liao, Wenyi Deng, Fangchuan Zhong Jan 2016

No Reduction By Propane Over Monolithic Cordierite-Based Fe/Al2o3 Catalyst: Reaction Mechanism And Effect Of H2o/So2, Hao Zhou, Yaxin Su, Wenyu Liao, Wenyi Deng, Fangchuan Zhong

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The selective reduction of NO by C3H8and the sensitivity to H2O and SO2have been studied over monolithic cordierite-based Fe/Al2O3catalysts, which were prepared by the sol–gel and impregnation method. The catalysts were investigated by N2 adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. Results showed that NO reduction was more than 90% in the absence of oxygen at 500 °C and in the presence of oxygen at 600 °C respectively. In a continues …


Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys Jan 2016

Pumping Of Fresh Concrete: Insights And Challenges, Geert De Schutter, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pumping of Fresh Concrete is of Utmost Importance for Concrete Practice. Required Pumping Pressures Are Typically Estimated based on Design Charts. However, with the Increased Use of Chemical Admixtures and the Development of More Flowable Concrete Mixtures, the Accuracy of Traditional Design Charts is Questioned. in Recent Years, Significant Progress Has Been Obtained in Understanding the Flow of the Material in the Pumping Pipe, Including the Behavior of the Lubrication Layer Near the Pipe Surface. in Comparison with Traditional Design Charts, This Results in More Reliable Pressure Predictions When Considering Very Fluid Concrete Types Like Self-Consolidating Concrete. Some Remaining Challenges …


Deployment And Performance Analyses Of High-Resolution Iowa Xpol Radar System During The Nasa Ifloods Campaign, Kumar Vijay Mishra, Witold F. Krajewski, Radoslaw Goska, Daniel Ceynar, Bong Chul Seo, Anton Kruger, James J. Niemeier, Miguel B. Galvez, Merhala Thurai, V. N. Bringi, Leonid Tolstoy, Paul A. Kucera, Walter A. Petersen, Jacopo Grazioli Jan 2016

Deployment And Performance Analyses Of High-Resolution Iowa Xpol Radar System During The Nasa Ifloods Campaign, Kumar Vijay Mishra, Witold F. Krajewski, Radoslaw Goska, Daniel Ceynar, Bong Chul Seo, Anton Kruger, James J. Niemeier, Miguel B. Galvez, Merhala Thurai, V. N. Bringi, Leonid Tolstoy, Paul A. Kucera, Walter A. Petersen, Jacopo Grazioli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This article presents the data collected and analyzed using the University of Iowa's X-band polarimetric (XPOL) radars that were part of the spring 2013 hydrology-oriented Iowa Flood Studies (IFloodS) field campaign, sponsored by NASA's Global Precipitation Measurement (GPM) Ground Validation (GV) program. The four mobile radars have full scanning capabilities that provide quantitative estimation of the rainfall at high temporal and spatial resolutions over experimental watersheds. IFloodS was the first extensive test of the XPOL radars, and the XPOL radars demonstrated their field worthiness during this campaign with 46 days of nearly uninterrupted, remotely monitored, and controlled operations. This paper …


Properties Of Self-Compacting Concrete With Recycled Coarse Aggregate, W. C. Tang, P. C. Ryan, H. Z. Cui, W. Liao Jan 2016

Properties Of Self-Compacting Concrete With Recycled Coarse Aggregate, W. C. Tang, P. C. Ryan, H. Z. Cui, W. Liao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The utilization of recycled concrete aggregate (RCA) in Self-Compacting Concrete (SCC) has the potential to reduce both the environmental impact and financial cost associated with this increasingly popular concrete type. However, to date limited research exists exploring the use of coarse RCA in SCC. The work presented in this paper seeks to build on the existing knowledge in this area by examining the workability, strength, and fracture properties of SCCs containing 0%, 25%, 50%, 75%, and 100% coarse RCA. The experimental programme indicated that at RCA utilization levels of 25% to 50% little or no negative impact was observed for …


Strain Distribution And Crack Detection In Thin Unbonded Concrete Pavement Overlays With Fully Distributed Fiber Optic Sensors, Yi Bao, Genda Chen Jan 2016

Strain Distribution And Crack Detection In Thin Unbonded Concrete Pavement Overlays With Fully Distributed Fiber Optic Sensors, Yi Bao, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims at evaluating the feasibility of strain measurement and crack detection in thin unbonded concrete pavement overlays with pulse prepump Brillouin optical time domain analysis. Single-mode optical fibers with two-layer and three-layer coatings, respectively, were applied as fully distributed sensors, their performances were compared with analytical predictions. They were successfully protected from damage during concrete casting of three full-scale concrete panels when 5 to 10-cm-thick protective mortar covers had been set for 2 h. Experimental results from three-point loading tests of the panels indicated that the strain distributions measured from the two types of sensors were in good …