Dynamic Evaluation of Transportation Structures with iPod-Based Data Acquisition

Abstract

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. ACKNOWLEDGEMENTSThe project team would like to acknowledge the generous support of NITC for the work documented in this report. The development of the laboratory and curriculum in the area of transportation and infrastructure health, as well as the increased capacity for applied research at Oregon Tech, would not have been possible without the institute's assistance. DISCLAIMERThe contents of this report reflect the views of the authors, who are solely responsible for the facts and the accuracy of the material and information presented herein. This document is disseminated under the sponsorship of the U.S. Department of Transportation University Transportation Centers Program in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof. The contents do not necessarily reflect the ...

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“…Results from previous research demonstrated the accuracy of iPod accelerometers as well as the limits of their precision (Riley, 2017). Additional work by graduate student, Samuel Lozano, to measure iPod accelerometer precision and compare it to a reference accelerometer and vision sensing measurements is included in the unpublished draft paper in Appendix A-1.…”

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