Generation stress distribution when using in the internal defective diagnostic manner of the large-sized casting structure and the concentration of stress region

摘要

PROBLEM TO BE SOLVED: To provide a method for diagnosing an internal defect in a large cast structure that can accurately detect the presence or absence of an internal defect in a cast article that is an initiation point of a fatigue crack, and to provide a method for extending the useful life of a large cast structure based on the diagnosis.;SOLUTION: The method includes: determining, by FEM analysis, the stress distribution generated when in use in a stress concentration region of a large cast structure; determining a critical dimension of an internal defect in the cast article that may develop a fatigue crack by the depth from the surface based on the FEM analysis resu and detecting presence or absence of an internal defect in the cast article that may develop a fatigue crack by a different inspection method according to the depth from the surface. When an internal defect in the cast article that may develop a fatigue crack is detected as a result, the useful life can be extended by cutting work.;COPYRIGHT: (C)2010,JPO&INPIT