Acoustic Emission Testing In Structure And Optimization Method For Damage Location

The experiments based on the measurement of load and deformation investigate on mechanical properties of rock-like materials,representing the relationship between stress and strain.As a special means of detection,acoustic emission(AE)directly indicates the internal fracturing or deformation in materials.It is of great significance to introduce the acoustic emission to the research of the mechanical properties of rock.Firstly the contact problem of the rock and AE sensor is solved.With AE testing of different rock types under uniaxial compression,the relationship between the AE signal and time or stress level is established.There are obvious differences between different rock types.The characteristics of AE in different rock types are different.Aiming at the key problem-AE source localization,the AIC method is introduced to improve the accuracy of arrival times of AE signals.By conducting the experiment of pencil-lead break on the surface of concrete specimen,the signals are captured and compiled to localize the AE source.Two algorithms of AE source localization are compared and optimized.The arrangement of AE sensors are discussed and finally the conclusion is reached that the actual source located in the center of sensors will improve the accuracy of AE source localization.