J Integral Evaluation of Side-Grooved CCT Specimens by Three-Dimensional Analyses

抄録

The 25% side-grooved CCT(center-cracked tension) specimens were analyzed elastic-plastically using the three-dimensional finite element method. The models used in analyses were CCT specimens which were of two thicknesses (B₀=18.4 mm) and 50 mm in width. The material was the general rolled steel (for structure). In the case of an 18mm-thick CCT specimen employing √(B<SUB)0·B_N> as the effective thickness, the load-vs-displacement curve of the specimen with side-grooves is higher by about 6% than that of a specimen without side-grooves. In the case of a 4mm-thick specimen, the former is higher by about 11% than the latter. The effect of the side-groove is greater on a 4mm-thick specimen than on an 18mm-thick specimen. The J value estimated by Rice's conventional equation using √(B<SUB)0·B_N> as the effective thickness nearly coincides with the J value at the central part of the specimen within about 6% error. it is possible to obtain a valid J_IC using the 25% side-grooved 4mm-thick specimen.