Smartdynamics a Mobile Phone Application Designed for Bridge Structural Assessments

Abstract

A mobile phone application, referred to as SMARTdynamics, was developed to take site readings of the dynamic response of a cable-stayed highway bridge and a three-span plate girder railway bridge by making use of built-in accelerometers. The application allows to determine key dynamic properties including natural frequencies, displacements, and damping ratios. SMARTdynamics includes a novel feature for smartphone accelerometers: the ability to control the sensor remotely with automated application feedback, allowing to record the dynamic response at specific times and with precision. The aim of the study was to determine the reliability of smartphone accelerometers, establish the effectiveness of mobile phone usage in the bridges and civil structures industry, and demonstrate that the derivation of more realistic dynamic properties can offer benefits in determining less conservative structural capacities. Acceleration readings were taken for a cable-stayed highway bridge to determine the tension force within the stay cables. The obtained results confirmed the viability of mobile phone ac-celerometers as a serious asset management tool. Site readings were also taken to determine the dynamic amplification factors of plate girder railway bridges and revealed a mean average reduction of 40% in the real dynamic increment factor when compared with values derived from codes of practice. The study confirmed that moving towards a realistic approach to bridge structural assessments with user-friendly and cost-effective tools can have tangible benefits and should be considered as a viable alternative to traditional methods.