Fractal analysis of damage detected by acoustic emissions in prestressed reinforced concrete beam under loading

摘要

For researching the relationship between prestressed reinforced concrete acoustic emissions (AE) signal and its damage evolution information, the paper studies AE signal parameter sequence fractal characteristics for destruction of whole process of prestressed reinforced concrete under different stress level. The research results show that in the process of destruction, AE signal energy parameter sequence has obvious fractal characters at a scale. AE process has different degree of self-similarity under different loading level, so the mechanical state beam structure can be described by the correlation dimension. It indicated that beam structure has damage when correlation dimension cuts down to a minimum and then reaches to the maximum. This model of the range of the changes reflects the damage degree. It will appear more serious damage when the correlation dimension is in stable state after damage. It gives the theoretical basis and methods for prestressed concrete structure health monitoring and nondestructive testing.