Abstract
Acoustic Emission (abbreviated as AE) is the transient elastic wave emission due to microfracturing in a solid. In the previous paper, theoretical representation of AE wave motions in concrete was reported by applying the theory of dislocation and elastodynamics. Once sources are mathematically described by the dislocation model, AE waveforms generated by various types of source mechanisms are characterized with emphasis on features of the radiation pattern, which is the spatial distribution of amplitude and polarization of first motions.
In this paper, fundamental studies in regard to radiation patterns of AE wave motions are reported. Such patterns are verified in the experiments. In the source location experiments, the types of sources can be classified into two groups from AE characteristics based on the radiation pattern. They are associated with tensile cracks and others.
From the relation between the radiation pattern and the dislocation model, in addition, the orientations of dislocation models may be determined. The improved source location technique useful for such an attempt is developed and applied in the experiments. The results show that the determination of source kinematics by the aid of the radiation pattern is promising in concrete.
