SIMULATION OF AE GENERATION BEHAVIOR IN 2-DIMENSIONAL POLYCRYSTALS BYUSING THE BODY FORCE METHOD

AE (Acoustic Emission) generation behavior during microfracture proces s of 2-dimensional alumina polycrystals is simulated along with its ch aracteristic parameters, by assuming that a microfracture corresponds to an AE event. The microfracture process is simulated by using the bo dy force method. Various AE generation behaviors are predicted as a fu nction of the grain boundary toughness (K-cb), the grain size and the distribution state of residual stresses due to crystalline anisotropy. The predicted AE events have a tendency to occur at higher stress wit h increasing K-cb and with decreasing grain size. By the fracture-mech anical calculation of the crack opening volume, the relative variation of AE amplitude is also simulated, The actual AE measurements are car ried out in vacuum for two kinds of alumina with different grain size, and compared with the simulated results. The cumulative AE event curv e for 11.5 mu m grain size shows good agreement with the simulation wh en the K-cb is 0.35 times the grain toughness (K-cg), and that for 28. 2 mu m shows good agreement with the simulation at K-cb = 0.45K(cg). T he results of AE location for both the simulation and the measurement show the similar characteristics of the scattered distribution over th e stressed fields.