Measurement data can facilitate the condition assessment of structures. Regardless of whether measurement data is collected in the course of a recurring inspection or a survey is conducted for quick analysis in the event of a disaster. Vibration measurement data can be used to detect changes in a structure or to determine system parameters (systemidentification). In this paper, the application suitability of smartphones and tablets for vibration measurement and systemidentification of bridges is addressed. The main focus lies on the principle possibility to use commercially available smartphones and tablets for the assessment of bridges without any special modifications. In order to investigate the applicability of smartphones and tablets, different experiments were carried out. To prove a theoretical suitability for application, a laboratory test with several series of measurements under different test configurations was carried out on a single-span girder. This was followed by a series of measurements on a test bridge on the site of the University of the German Armed Forces in order to be able to investigate the suitability for use under real conditions and with environmental influences. The investigations on the general suitability of smartphones and tablets for vibration measurement on bridges were concluded by a test on a road bridge under running traffic. The series of measurements on the test bridge on the site of the University of the German Armed Forces were carried out under different test configurations, in which the static system of the bridge was changed for each configuration. These measurement series were used to investigate the extent to which measurements by smartphones and tablets are sensitive enough to detect system changes. The measurement data was used to determine natural frequencies and damping parameters. These were then compared with each other and with the natural frequencies and damping parameters determined with the measurement data from a classical vibration measurement system. The evaluations with respect to the general suitability for application and with respect to the system identification were carried out with the help of classical signal processing methods. These include the Fourier-Transformation and the Hilbert-Transformation. The results presented in this paper suggest that smartphones and tablets are suitable for the general measurement of vibrations on bridges. Natural frequencies could be detected with sufficient accuracy using the signals from the smartphones and tablets. It was noticeable that younger smartphones provided better results than older tablets. The determination of damping parameters showed similar results when comparing selected smartphones with the classic vibration measurement system. The limiting factor turned out to be the sensitivity of the smartphones and tablets. To generate an amplitude in the structure large enough to be recorded by a smartphone or tablet, the excitation must be large enough in relation to the stiffness of the structure. It can be assumed that the sensitivity of a smartphone’s and a tablet’s motion sensors will continue to increase with further development of technology.    «

Measurement data can facilitate the condition assessment of structures. Regardless of whether measurement data is collected in the course of a recurring inspection or a survey is conducted for quick analysis in the event of a disaster. Vibration measurement data can be used to detect changes in a structure or to determine system parameters (systemidentification). In this paper, the application suitability of smartphones and tablets for vibration measurement and systemidentification of bridges is a...    »