Center notched concrete beams reinforced with carbon and glass fiber rein- forced plastic sheets were subjected to three-point flexure loading. Con- ventional AE parameter analysis showed that the beginning of continuous occurrence and exponentially increment of AE activities corresponds to…
Center notched concrete beams reinforced with carbon and glass fiber rein- forced plastic sheets were subjected to three-point flexure loading. Con- ventional AE parameter analysis showed that the beginning of continuous occurrence and exponentially increment of AE activities corresponds to the critical load at which the crack initiates at the notch tip. The critical stress intensity factor of the notch tip was calculated based on the crack tension method using the estimated critical load. A moment tensor analysis was applied to the AE waveform sets recorded at six sensors. On the basis of the arrival time differences and the amplitudes of the first motions of the waveforms, crack locations were determined and AE source was classified into a tensile crack or a shear crack. The failure process resulted form the moment tensor analysis was in good agreement with visual observations.