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• 1. [Article] A study of single angle compression members

  A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were ...

  Citation × Citation Citation Abstract Copy Title: A study of single angle compression members Author: Callaway, James Robert Year: 1983 A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed. Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, an inelastic method, was developed by Mueller and Erzurumlu of Portland State University. Comparisons were made with the results of the test program. The results indicate that both analytic models give conservative predictions when pinned end conditions are assumed and unconservative results for fixed end conditions. For the test members with L/r ratios greater than 125, the elastic method results closely paralleled the test results but for the members with L/r ratios less than 125 the correlation was less consistent. The results of the inelastic technique closely paralleled the results of all the member tests. Title: A study of single angle compression members Author: Callaway, James Robert Year: 1983 A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed. Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, an inelastic method, was developed by Mueller and Erzurumlu of Portland State University. Comparisons were made with the results of the test program. The results indicate that both analytic models give conservative predictions when pinned end conditions are assumed and unconservative results for fixed end conditions. For the test members with L/r ratios greater than 125, the elastic method results closely paralleled the test results but for the members with L/r ratios less than 125 the correlation was less consistent. The results of the inelastic technique closely paralleled the results of all the member tests. Close

• 2. [Article] Evaluating and Adaptive Signal Control System in Gresham

  Cities and Counties are faced with increasing traffic congestion due to rapidly increasing population. Like many agencies, the City of Gresham has struggled with how to manage the increasing congestion ...

  Citation × Citation Citation Abstract Copy Title: Evaluating and Adaptive Signal Control System in Gresham Author: Peters, James M., McCoy, Jay, Bertini, Robert L. Year: 2007 Cities and Counties are faced with increasing traffic congestion due to rapidly increasing population. Like many agencies, the City of Gresham has struggled with how to manage the increasing congestion with limited funds for major roadway widening projects. Gresham has recognized the need to optimize existing system capacity to get the most out of their current transportation system infrastructure investment. In 2005, the City of Gresham, in cooperation with numerous agencies in the Portland metropolitan area, evaluated a variety of signal control systems including traditional time-of-day coordination, traffic responsive, and adaptive signal control systems. Based on that evaluation, the steering committee selected and deployed the SCATS adaptive signal control system on Burnside Road between Eastman Parkway and Powell Boulevard. The Burnside corridor in Gresham, OR is a 5 lane major arterial that carries approximately 38,000 ADT. Burnside serves as a main through route connecting I-84 to OR 26 and Mt. Hood. The SCATS system has been integrated with the existing shared regional traffic signal system and is available for expansion to other jurisdictions in the region. This paper describes the process used to evaluate the results of the adaptive signal control system and how they compare to the original project objectives. The evaluation compares changes in travel time, delay, stops and fuel consumption associated with “free” (uncoordinated), time-of-day coordinated and the new adaptive signal system on Burnside Road. This paper should be of interest to other state and local agencies interested in trying to optimize existing arterial capacity. Title: Evaluating and Adaptive Signal Control System in Gresham Author: Peters, James M., McCoy, Jay, Bertini, Robert L. Year: 2007 Cities and Counties are faced with increasing traffic congestion due to rapidly increasing population. Like many agencies, the City of Gresham has struggled with how to manage the increasing congestion with limited funds for major roadway widening projects. Gresham has recognized the need to optimize existing system capacity to get the most out of their current transportation system infrastructure investment. In 2005, the City of Gresham, in cooperation with numerous agencies in the Portland metropolitan area, evaluated a variety of signal control systems including traditional time-of-day coordination, traffic responsive, and adaptive signal control systems. Based on that evaluation, the steering committee selected and deployed the SCATS adaptive signal control system on Burnside Road between Eastman Parkway and Powell Boulevard. The Burnside corridor in Gresham, OR is a 5 lane major arterial that carries approximately 38,000 ADT. Burnside serves as a main through route connecting I-84 to OR 26 and Mt. Hood. The SCATS system has been integrated with the existing shared regional traffic signal system and is available for expansion to other jurisdictions in the region. This paper describes the process used to evaluate the results of the adaptive signal control system and how they compare to the original project objectives. The evaluation compares changes in travel time, delay, stops and fuel consumption associated with “free” (uncoordinated), time-of-day coordinated and the new adaptive signal system on Burnside Road. This paper should be of interest to other state and local agencies interested in trying to optimize existing arterial capacity. Close

• 3. [Article] Development of an Open Source Bridge Management System

  A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing ...

  Citation × Citation Citation Abstract Copy Title: Development of an Open Source Bridge Management System Author: Scott, Michael H. Year: 2011 A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing live load analysis through scripts and experimenting with emergent bridge rating methodologies. Since Tcl is an interpreted language, the application also has the important advantage that new bridge capacity models and rating factor calculations can be implemented on multiple platforms without compiling source code. The network programming features of Tcl give the system access to databases for conducting internet-based bridge rating. The system is demonstrated for rating a conventionally reinforced concrete girder; however, it is readily extensible to other types of bridge components. Title: Development of an Open Source Bridge Management System Author: Scott, Michael H. Year: 2011 A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing live load analysis through scripts and experimenting with emergent bridge rating methodologies. Since Tcl is an interpreted language, the application also has the important advantage that new bridge capacity models and rating factor calculations can be implemented on multiple platforms without compiling source code. The network programming features of Tcl give the system access to databases for conducting internet-based bridge rating. The system is demonstrated for rating a conventionally reinforced concrete girder; however, it is readily extensible to other types of bridge components. Close

• 4. [Article] Adaptation of Classical Tidal Harmonic Analysis to Nonstationary Tides, with Application to River Tides

  One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis ...

  Citation × Citation Citation Abstract Copy Title: Adaptation of Classical Tidal Harmonic Analysis to Nonstationary Tides, with Application to River Tides Author: Matte, Pascal, Jay, David A., Zaron, Edward D. Year: 2013 One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis tool has been developed, NS_TIDE, adapted to the study of nonstationary signals, in this case, river tides. It builds the nonstationary forcing directly into the tidal basis functions. It is implemented by modification of T_TIDE; however, certain concepts, particularly the meaning of a constituent and the Rayleigh criterion, are redefined to account for the smearing effects on the tidal spectral lines by nontidal energy. An error estimation procedure is included that constructs a covariance matrix of the regression coefficients, based on either an uncorrelated or a correlated noise model. The output of NS_TIDE consists of time series of subtidal water levels [mean water level (MWL)] and tidal properties (amplitudes and phases), expressed in terms of external forcing functions. The method was tested using records from a station on the Columbia River, 172 km from the ocean entrance, where the tides are strongly altered by river flow. NS_TIDE hindcast explains 96.4% of the signal variance with a root-mean-square error of 0.165 m obtained from 288 parameters, far better than traditional harmonic analysis (38.5%, 0.604 m, and 127 parameters). While keeping the benefits of harmonic analysis, its advantages compared to existing tidal analysis methods include its capacity to distinguish frequencies within tidal bands without losing resolution in the time domain or data at the endpoints of the time series. Title: Adaptation of Classical Tidal Harmonic Analysis to Nonstationary Tides, with Application to River Tides Author: Matte, Pascal, Jay, David A., Zaron, Edward D. Year: 2013 One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis tool has been developed, NS_TIDE, adapted to the study of nonstationary signals, in this case, river tides. It builds the nonstationary forcing directly into the tidal basis functions. It is implemented by modification of T_TIDE; however, certain concepts, particularly the meaning of a constituent and the Rayleigh criterion, are redefined to account for the smearing effects on the tidal spectral lines by nontidal energy. An error estimation procedure is included that constructs a covariance matrix of the regression coefficients, based on either an uncorrelated or a correlated noise model. The output of NS_TIDE consists of time series of subtidal water levels [mean water level (MWL)] and tidal properties (amplitudes and phases), expressed in terms of external forcing functions. The method was tested using records from a station on the Columbia River, 172 km from the ocean entrance, where the tides are strongly altered by river flow. NS_TIDE hindcast explains 96.4% of the signal variance with a root-mean-square error of 0.165 m obtained from 288 parameters, far better than traditional harmonic analysis (38.5%, 0.604 m, and 127 parameters). While keeping the benefits of harmonic analysis, its advantages compared to existing tidal analysis methods include its capacity to distinguish frequencies within tidal bands without losing resolution in the time domain or data at the endpoints of the time series. Close

• 5. [Article] Experimental Tests and Numerical Analyses of Steel Truss Bridge Gusset Connections

  The collapse of the I-35W Bridge in Minneapolis, Minnesota has raised questions regarding the performance and possibly safety of steel truss bridges. The failure investigation indicated that the collapse ...

  Citation × Citation Citation Abstract Copy Title: Experimental Tests and Numerical Analyses of Steel Truss Bridge Gusset Connections Author: Higgins, Christopher, Dusicka, Peter, Scott, Michael Year: 2012 The collapse of the I-35W Bridge in Minneapolis, Minnesota has raised questions regarding the performance and possibly safety of steel truss bridges. The failure investigation indicated that the collapse was due to a design error in the gusset plates used to connect the truss members. The findings also recommend that evaluation of truss connections will be needed, which is a deviation from past practice where only members were considered. Gusset plates connect individual steel truss bridge members together at a node. In 10% of the 200,000 steel bridges in US in 2008, failure of a single truss or connection could lead to collapse. Regular inspection and load rating are essential for the safe operation and maintenance of these bridges. The Minneapolis I-35 Bridge collapse was the first gusset failure where a design flaw was implicated. Load rating gusset plates is a significant challenge given the number of connections and the complexity of accurately evaluating each one. The majority of research on gusset plate strength is from small-scale connections. More refined techniques are needed to conduct high-fidelity capacity evaluations. Finite element analysis (FEA) is widely used in structural engineering. Using FEA in gusset plate evaluation presents challenges due to the connections’ large-scale, high degree of geometric variability and complex load paths. Title: Experimental Tests and Numerical Analyses of Steel Truss Bridge Gusset Connections Author: Higgins, Christopher, Dusicka, Peter, Scott, Michael Year: 2012 The collapse of the I-35W Bridge in Minneapolis, Minnesota has raised questions regarding the performance and possibly safety of steel truss bridges. The failure investigation indicated that the collapse was due to a design error in the gusset plates used to connect the truss members. The findings also recommend that evaluation of truss connections will be needed, which is a deviation from past practice where only members were considered. Gusset plates connect individual steel truss bridge members together at a node. In 10% of the 200,000 steel bridges in US in 2008, failure of a single truss or connection could lead to collapse. Regular inspection and load rating are essential for the safe operation and maintenance of these bridges. The Minneapolis I-35 Bridge collapse was the first gusset failure where a design flaw was implicated. Load rating gusset plates is a significant challenge given the number of connections and the complexity of accurately evaluating each one. The majority of research on gusset plate strength is from small-scale connections. More refined techniques are needed to conduct high-fidelity capacity evaluations. Finite element analysis (FEA) is widely used in structural engineering. Using FEA in gusset plate evaluation presents challenges due to the connections’ large-scale, high degree of geometric variability and complex load paths. Close

• 6. [Article] Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data

  Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of ...

  Citation × Citation Citation Abstract Copy Title: Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data Author: Feng, Wei, Figliozzi, Miguel A. Year: 2015 Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that help analyze the causes and effects of bus bunching based on AVL/APC data. Temporal and spatial distributions of bus bunching events indicate high concentration during high frequency service hours and segments, and increasing concentration toward downstream. Time point bus stops can help reduce bus headway variability but with limited capability. Results indicate that irregular departure headway at the initial stop is the key cause of bus bunching rather than downstream traffic conditions and passenger demand uncertainty. A bus departure headway control at the initial stop of high frequency service zone is highly recommended, and a switch from schedule-based control to headway-based control strategy at time point stops in high frequency service zone is suggested. Title: Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data Author: Feng, Wei, Figliozzi, Miguel A. Year: 2015 Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that help analyze the causes and effects of bus bunching based on AVL/APC data. Temporal and spatial distributions of bus bunching events indicate high concentration during high frequency service hours and segments, and increasing concentration toward downstream. Time point bus stops can help reduce bus headway variability but with limited capability. Results indicate that irregular departure headway at the initial stop is the key cause of bus bunching rather than downstream traffic conditions and passenger demand uncertainty. A bus departure headway control at the initial stop of high frequency service zone is highly recommended, and a switch from schedule-based control to headway-based control strategy at time point stops in high frequency service zone is suggested. Close

• 7. [Article] Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor

  Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective ...

  Citation × Citation Citation Abstract Copy Title: Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor Author: Kothuri, Sirisha Murthy, Koonce, Peter, Monsere, Christopher M., Reynolds, Titus Year: 2015 Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians and all users. From a pedestrian perspective, free operation was found to be more beneficial due to lower delays. However, from a system wide (all user) perspective, coordinated operation showed the greatest benefits with lowest system delay under heavy traffic conditions (v/c > 0.7). In the off-peak conditions when traffic volumes are lower, free operation resulted in lowest system delay (v/c < 0.7). During coordination, lower cycle lengths were beneficial for pedestrians, due to smaller delays. The results revealed that volume to capacity (v/c) ratios for the major street volumes coupled with pedestrian actuation frequency for the side street phases, could be used to determine the signal controller mode of operation that produces the lowest system delay. The results were used to create a guidance matrix for controller mode based on pedestrian and vehicle volumes. To demonstrate application, the matrix is applied to another corridor in a case study approach. Title: Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor Author: Kothuri, Sirisha Murthy, Koonce, Peter, Monsere, Christopher M., Reynolds, Titus Year: 2015 Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians and all users. From a pedestrian perspective, free operation was found to be more beneficial due to lower delays. However, from a system wide (all user) perspective, coordinated operation showed the greatest benefits with lowest system delay under heavy traffic conditions (v/c > 0.7). In the off-peak conditions when traffic volumes are lower, free operation resulted in lowest system delay (v/c < 0.7). During coordination, lower cycle lengths were beneficial for pedestrians, due to smaller delays. The results revealed that volume to capacity (v/c) ratios for the major street volumes coupled with pedestrian actuation frequency for the side street phases, could be used to determine the signal controller mode of operation that produces the lowest system delay. The results were used to create a guidance matrix for controller mode based on pedestrian and vehicle volumes. To demonstrate application, the matrix is applied to another corridor in a case study approach. Close

• 8. [Article] A Level-of-Service Model for Protected Bike Lanes

  Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of ...

  Citation × Citation Citation Abstract Copy Title: A Level-of-Service Model for Protected Bike Lanes Author: Foster, Nick, Monsere, Christopher, Dill, Jennifer, Clifton, Kelly Year: 2015 Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted in Portland, OR with video footage gathered in Chicago, IL, Portland, OR and San Francisco, CA. The model is for road segments only and not signalized intersections. It complements the Highway Capacity Manual 2010 level-of- service methods by providing an analysis procedure for a facility type that is not currently included in the manual. The model indicates that the type of buffer, direction of travel (one-way vs. two-way), adjacent motor vehicle speed limit, and average daily motor vehicle volumes are all significant predictors of bicyclist comfort in protected bike lanes. The model predicts a mean value of ‘A’ or ‘B’ on an A (most comfortable) – F (least comfortable) scale for all protected bike lane clips used in the survey. Consistent with previous research findings, survey respondents report that protected bike lanes are generally more comfortable than other types of on-street infrastructure. Title: A Level-of-Service Model for Protected Bike Lanes Author: Foster, Nick, Monsere, Christopher, Dill, Jennifer, Clifton, Kelly Year: 2015 Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted in Portland, OR with video footage gathered in Chicago, IL, Portland, OR and San Francisco, CA. The model is for road segments only and not signalized intersections. It complements the Highway Capacity Manual 2010 level-of- service methods by providing an analysis procedure for a facility type that is not currently included in the manual. The model indicates that the type of buffer, direction of travel (one-way vs. two-way), adjacent motor vehicle speed limit, and average daily motor vehicle volumes are all significant predictors of bicyclist comfort in protected bike lanes. The model predicts a mean value of ‘A’ or ‘B’ on an A (most comfortable) – F (least comfortable) scale for all protected bike lane clips used in the survey. Consistent with previous research findings, survey respondents report that protected bike lanes are generally more comfortable than other types of on-street infrastructure. Close

• 9. [Article] Improved Methodology for Limit States Finite Element Analysis of Lattice Type Structures using Nonlinear Post-Buckling Member Performance

  In an attempt to achieve more efficient designs, the technological frontier is pushed further and further. Every year science probes for a better understanding of natural phenomena, discovering new and ...

  Citation × Citation Citation Abstract Copy Title: Improved Methodology for Limit States Finite Element Analysis of Lattice Type Structures using Nonlinear Post-Buckling Member Performance Author: Ostendorp, Markus Year: 1992 In an attempt to achieve more efficient designs, the technological frontier is pushed further and further. Every year science probes for a better understanding of natural phenomena, discovering new and improved methods to perform the same task more efficiently and with better results. One of the new technologies is the nonlinear analysis of structural systems using inelastic post-buckling member performance. Inelastic post-buckling member performance is defined as the constitutive relationship between axial load and displacement after the ultimate member capacity has been exceeded. A nonlinear analysis is able to predict the failure behavior of a structural system under ultimate loads more accurately than the traditionally used linear elastic analysis. Consequently, designs can be improved and become more efficient, which reduces the realization cost of a project. An improved nonlinear analysis solution algorithm has been developed, that allows the analyst to perform a nonlinear analysis using post-buckling member performances faster than previously possible. Furthermore, the original post-buckling member performance database was expanded using results obtained from physical member compression tests. Based on the experimental results, new post-buckling member performance model curves were developed to be used together with the improved nonlinear solution algorithm. In addition, a program was developed that allows the analyst to perform a valid nonlinear analysis using a finite element program (LIMIT). The program combines a numerical pre-processor, and input and output data evaluation modules based on human expertise together with the LIMIT analysis package. Extensive on-line help facilities together with graphical pre- and post-processors were also integrated into the program. The resulting analysis package essentially combines all of the necessary components required to perform a nonlinear analysis using post-buckling member performances into one complete analysis package. Title: Improved Methodology for Limit States Finite Element Analysis of Lattice Type Structures using Nonlinear Post-Buckling Member Performance Author: Ostendorp, Markus Year: 1992 In an attempt to achieve more efficient designs, the technological frontier is pushed further and further. Every year science probes for a better understanding of natural phenomena, discovering new and improved methods to perform the same task more efficiently and with better results. One of the new technologies is the nonlinear analysis of structural systems using inelastic post-buckling member performance. Inelastic post-buckling member performance is defined as the constitutive relationship between axial load and displacement after the ultimate member capacity has been exceeded. A nonlinear analysis is able to predict the failure behavior of a structural system under ultimate loads more accurately than the traditionally used linear elastic analysis. Consequently, designs can be improved and become more efficient, which reduces the realization cost of a project. An improved nonlinear analysis solution algorithm has been developed, that allows the analyst to perform a nonlinear analysis using post-buckling member performances faster than previously possible. Furthermore, the original post-buckling member performance database was expanded using results obtained from physical member compression tests. Based on the experimental results, new post-buckling member performance model curves were developed to be used together with the improved nonlinear solution algorithm. In addition, a program was developed that allows the analyst to perform a valid nonlinear analysis using a finite element program (LIMIT). The program combines a numerical pre-processor, and input and output data evaluation modules based on human expertise together with the LIMIT analysis package. Extensive on-line help facilities together with graphical pre- and post-processors were also integrated into the program. The resulting analysis package essentially combines all of the necessary components required to perform a nonlinear analysis using post-buckling member performances into one complete analysis package. Close

• 10. [Article] Dynamic Evaluation of Transportation Structures with iPod-Based Data Acquisition

  This grant supported coursework and laboratory development and expanded research capacity, promoting (a) innovative learning activities that expose students to cutting-edge methods of bridge structural ...

  Citation × Citation Citation Abstract Copy Title: Dynamic Evaluation of Transportation Structures with iPod-Based Data Acquisition Author: Riley, Charles Year: 2017 This grant supported coursework and laboratory development and expanded research capacity, promoting (a) innovative learning activities that expose students to cutting-edge methods of bridge structural health and behavior monitoring and (b) research by our growing group of graduate students using developing technologies (specifically, shake tables and iPods with on-board accelerometers). As transportation infrastructure reaches and exceeds its design life, engineering efforts are turning to evaluation, rehabilitation and repair. Accurately assessing structures to determine their future performance and remaining life is becoming a primary job function for many civil engineers. As part of this project, graduate students worked with the PI to develop course modules that employed iPods in the laboratory and classroom to introduce concepts of vibrations, dynamic evaluation methods, structural health monitoring, and damage detection. Learning gains as a result of the module were assessed with both direct and indirect methods. While learning gains appeared stronger for students who participated in the hands-on component of the laboratory, due to the small class size there were no statistically significant differences between using iPods in a hands-on laboratory versus a purely computational laboratory. However, students indicated that iPods and hands-on laboratories were their preferred experience. The team also investigated laboratory and field applications, as well as effectiveness, of iPods to study structural dynamics and structural health monitoring methods, specifically for area bridges and other transportation structures. Sensor networks and mobile device-based accelerometers are beginning to be recognized as a valid means for conducting structural evaluations. The equipment purchased with this grant allowed for a new laboratory to be developed at Oregon Tech to support multiple undergraduate and graduate elective courses including Bridge Rating, Bridge Design, Transportation Structures, and Structural Dynamics. The Structural Health and Kinetic Evaluation (SHAKE) Laboratory and the associated equipment will support education and research efforts at Oregon Tech well into the future. Title: Dynamic Evaluation of Transportation Structures with iPod-Based Data Acquisition Author: Riley, Charles Year: 2017 This grant supported coursework and laboratory development and expanded research capacity, promoting (a) innovative learning activities that expose students to cutting-edge methods of bridge structural health and behavior monitoring and (b) research by our growing group of graduate students using developing technologies (specifically, shake tables and iPods with on-board accelerometers). As transportation infrastructure reaches and exceeds its design life, engineering efforts are turning to evaluation, rehabilitation and repair. Accurately assessing structures to determine their future performance and remaining life is becoming a primary job function for many civil engineers. As part of this project, graduate students worked with the PI to develop course modules that employed iPods in the laboratory and classroom to introduce concepts of vibrations, dynamic evaluation methods, structural health monitoring, and damage detection. Learning gains as a result of the module were assessed with both direct and indirect methods. While learning gains appeared stronger for students who participated in the hands-on component of the laboratory, due to the small class size there were no statistically significant differences between using iPods in a hands-on laboratory versus a purely computational laboratory. However, students indicated that iPods and hands-on laboratories were their preferred experience. The team also investigated laboratory and field applications, as well as effectiveness, of iPods to study structural dynamics and structural health monitoring methods, specifically for area bridges and other transportation structures. Sensor networks and mobile device-based accelerometers are beginning to be recognized as a valid means for conducting structural evaluations. The equipment purchased with this grant allowed for a new laboratory to be developed at Oregon Tech to support multiple undergraduate and graduate elective courses including Bridge Rating, Bridge Design, Transportation Structures, and Structural Dynamics. The Structural Health and Kinetic Evaluation (SHAKE) Laboratory and the associated equipment will support education and research efforts at Oregon Tech well into the future. Close