Characterization of the Damage Process of Polypropylene Fiber Mortar at Medium Loading Rate by the Full Wave Acoustic Emission Technique

Abstract

In order to obtains the damage characteristics of the polypropylene fiber mortar at medium loading rate (10^–3 s^–1). The damage evolution process (A, B and C stages) of mortar specimens with different polypropylene fiber content under uniaxial tension was studied by using the full waveform acoustic emission technology. The acoustic emission wavelet energy and spectrum characteristics of cd7 frequency band were analyzed. The results showed that with the increase of the polypropylene fiber content, the peak stress increases firstly and then decreases, the elastic modulus increases gradually, the peak frequency of cd7 frequency band decreases in the A and B stages but increases in the C stages. The peak frequency of cd7 frequency band down from 30–40 kHz to 20–30 kHz with the damage accumulation, the above characteristics can be used to identify the damage stages and damage mechanisms.