放射線遮へいガラスの微小塑性挙動に及ぼすレーザー照射の影響

抄録

Pulsed laser irradiation and indentation tests on radiation shielding glasses with the different lead content and a lead-free glass were carried out. The size of irradiation damage of the glass with high lead content was larger than that with low content and the threshold of the damage initiation of the glass with high lead content was lower than that with low content. Constants in the material constitutive equation expressing the micro plastic behavior of glasses were quantitatively determined using the inverse analyses with Kalman’s filter and a finite element method based on indentation load-depth curves. Flow stress decreased with an increase of lead content and that in irradiated area was lower than that in unirradiated area. On the other hand, plastic flow resistance increased with an increase of the lead content and that in irradiated area was higher than that in unirradiated area. Fracture energy and critical size of plastic zone around tip of crack in unirradiated and irradiated areas were calculated based on experimental results including constants evaluated using the inverse analysis. These values decreased with an increase of the lead content and these values in irradiated area were lower than that in unirradiated area.