抄録
Microfracture process in ceramics was analyzed using Monte-Carlo simulation. It was supposed in the simulation that the microfracture process consists of the maincrack formation resulted from the growth and coalescence of pre-existing microcracks, and the propagation of maincrack to final failure. To determine the crack growth parameters for simulation, microfracture process in alumina ceramics was characterized by acoustic emission technique, and the critical stress for maincrack formation and final strength were determined and compared with the results of simulation. The Monte-Carlo simulation assuming the 3 microcracks array with random size was adapted to the fracture analysis during the proof test with various proof stresses and holding times as well as residual strength measurements. The time-to-maincrack formation, yields and residual strength were calculated and it was found that they showed good agreement with the several experimental results. Consequently, the proof test with the wide range of proof stresses and holding times were examined and their influence on the yields, residual strength and lifetime was discussed.
