EVALUATION OF LOW-COST MEMS ACCELEROMETERS FOR SHM: FREQUENCY AND DAMPING IDENTIFICATION OF CIVIL STRUCTURES

Abstract

SENSING TECHNIQUES BASED ON VIBRATION MEASUREMENT FOR MODAL ANALYSIS ARE ONE OF THE MOST STUDIED AND APPLIED IN SHM IN CIVIL STRUCTURES. ACCELEROMETERS ARE USED TO MEASURE STRUCTURAL VIBRATION FOR LATER MODAL PARAMETERS IDENTIFICATION. THE ADVENT OF LOW-COST MEMS ACCELEROMETERS AND OPEN-SOURCE ELECTRONIC PLATFORMS, SUCH AS ARDUINO, HAVE FACILITATED THE DESIGN OF LOW-COST SYSTEMS SUITABLE FOR MODAL IDENTIFICATION, ALTHOUGH THERE IS STILL A LACK OF STUDIES REGARDING PRACTICAL APPLICATION AND COMPARISON OF COMMERCIALLY AVAILABLE LOW-COST ACCELEROMETERS UNDER SHM CONDITIONS. THIS WORK PRESENTS AN EXPERIMENTAL PERFORMANCE EVALUATION OF SIX LOW-COST MEMS ACCELEROMETERS, USING AN ARDUINO-BASED DATA ACQUISITION SYSTEM, FOR THE IDENTIFICATION OF NATURAL FREQUENCIES AND DAMPING RATIOS OF CIVIL STRUCTURES. THE RESULTS SHOWED AN OVERALL GOOD PERFORMANCE OF THE MEMS ACCELEROMETER, WITH IDENTIFIED NATURAL FREQUENCIES ERRORS WITHIN 1.02% AND 7.76% OF REFERENCE VALUES, FOR THE THREE-STOREY FRAME AND CONCRETE SLAB, RESPECTIVELY, AND A NOISE DENSITY AS LOW AS 108 G/√HZ.