Acoustic emission source localisation on bone using multiple regression
A regression source location algorithm is developed to locate microcracks in bovine bone samples. Bone samples measuring 60 mm long, 22 mm wide and 5.5 mm thick were harvested from bovine femora. Artificial acoustic emission sources were created on the bone samples. The known location of these acoustic emission sources and the recorded arrival times at four acoustic emission sensors were used to develop regression equations, which when given new arrival time data could compute the acoustic emission source location. The regression equations were tested to determine if they could locate artificial acoustic emission sources and then acoustic emission emanating from microcracks in three–point bend tests. Results for the artificial acoustic emission source tests gave a mean absolute error of 0.69 mm and 0.71 mm for the X and Y coordinates respectively. In three–point bend tests a good spatial correlation was observed between the located microcracks and the observed fracture location.
Keywords: bovine bone, bone fracture, microcracks, acoustic emission, source location, multiple regression, regression equations, AE velocity, complex structures