Abstract
In order to acquire the physical information about the evolution of microcraks in concrete in real time, three typical types of acoustic emission (AE) signals are identified by the wavelet transform of experimentally collected AE signals. The whole compressive fracture process of concrete is divided into four stages, i.e., microvoid compressive closure, crack initiation, crack growth and crack coalescence, on the basis of the event density fluctuation of AE signals andthe fracture theory of brittle materials. Based on the inverse proportional relationship between the frequency of AE signal and crack size, and the distribution characteristics of the three types of AE signals at four fracture stages, the AE signals are associated with crack initiation, crack growth (or microvoid compressive closure) and crack coalescence, respectively. The experimental results show that the rise times and frequencies of AE signals caused by crack initiation, crack growth (or microvoid compressive closure) and crack coalescence increase in turns and decrease gradually, respectively, which conform to the strain energy release theory.
Original language | English |
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Pages (from-to) | 1745-1753 |
Number of pages | 9 |
Journal | Binggong Xuebao/Acta Armamentarii |
Volume | 38 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 Sept 2017 |
Keywords
- Acoustic emission
- Concrete
- Damage mechanism
- Solid mechanics
- Wavelet transform