Abstract Summary
Android mobile devices are provided with sensors that allow to monitor several aspects in terms of motion and position of the device; these sensors are hardware-based physical components built into the device, operated by software and mobile apps, providing us with data about motion, temperature, position, and environment in general. Correlation analises on vibration data recorded on structures are at the base of many methods that allow to extract important modal information from the recorded data. This type of data acquisition demands a high level of time accuracy in order the correlation analyses to be successful. It follows that, whenever data is recorded by different mobile devices, some sort of syncronyzation between them is required to allow for the necessary precision in time of the recordings. This paper presents the results obtained with a recent solution in which vibration data is picked up with multiple Android mobile phones equipped with accelerometers, and is then transmitted to a server over a wireless connection to be analyzed in time on the base of a synchronization procedure. The subject of this study are the recodings of the floor vibrations of a recently constructed building.These are compared with the recordings coming from professional grade accelerometric sensors. The capabilities of the proposed recoding technique are discussed on the base of the precision in recovering the mode shapes of a flexible floor from the acceleration records, and also at the ligth of the ralative ease with which Android mobile phones are becoming more available, capable, and less expensive.
