Creating a smartphone application for measuring responses of an experimental structure at multiple locations and for K-12 STEM outreach related to structural engineering.

摘要

Structural health monitoring (SHM) systems are used to measure and analyze structure data (e.g., floor accelerations and strains in structural members) to identify damage (or structural changes) to a structure. With aging infrastructures and collapses of recent structures such as the 2007 I-35W Mississippi River Bridge and the 2013 clothing factory in Bangladesh, SHM can help address an important societal issue in structural safety and reliability. In the current practice, SHM systems include dedicated sensors linked (via wires or wirelessly) to data acquisition systems. These sensing systems are typically costly and impractical for many educational curriculums. A lack of exposures to college students limits applications and understanding of SHM in the practicing engineering industry. By replacing these dedicated sensing systems with a common technology such as smartphones, this thesis project aims to make SHM experiments inexpensive and practical to college students. Additionally, the project can assist in exposing K-12 students to SHM and the general field of structural engineering at a young age and increasing their interest in becoming engineers.;This multidisciplinary research included developing a smartphone application using the Java(TM) programming language on the Android platform. The application utilizes the phone's user interface, internal accelerometer, internal storage, and Bluetooth to create a user friendly experience. One portion of the application is used for SHM purposes. It assists users in time-synchronizing multiple phones, recording acceleration data and detecting changes in structural properties. When compared to a dedicated sensing system used in a lab setting, data from the smartphones produced similar results.;Another portion of the application, incorporated into an educational outreach program at a local middle school, was designed to help students understand the basic concepts of structural dynamics --- more specifically, how stiffness and damping affect a structure's motions. This interactive smartphone application, coupled with its ability to be a cost-effective system for measuring structural responses in classroom experiments, can get students excited about engineering.