抄録
Cracking and delamination of brittle coating under equi-biaxial tension are investigated using the ring-on-ring test apparatus. As the specimen, brittle paint (stress-analysis paint) was coated on the surface of the substrate of PMMA (polymethyl methacrylate). The in-plane and the interface strengths of the brittle coating were changed by drying temperature of the paint. After the ring-on-ring test, the total length of the cracking and the delamination area were measured. In the coating dried at 30℃, both delamination and cracking increase with the strain. However, in the coating dried at 60℃, delamination is predominant and the spread of cracking with the strain is little when the applied equi-biaxial strain is not small (over 1500 microstrain). Furthennore, scale-like cracking pattern was observed in the coating dried at 60℃.
