Research on the Crack Initiation Criteria for the Existing Crack Defects in Corroded Steels

Steel structures that have been in service in the harsh environment for many years, often suffer from macroscopic cracks and surface corrosion damage at the same time. In order to properly evaluate the reduction degree of crack initiation threshold of existing crack defects in corroded steel structures, the paper studied the crack initiation criteria for existing crack defects in corroded steels. Through the tensile tests of cracked corroded steel plates, and the fracture analysis based on microscopic mechanism, the fracture initiation criterion for existed crack defects in corroded steels was established. The results showed that surface corrosion greatly reduced the critical loads of the existing cracks in the steel structure. According to the micro fracture mechanism of hole initiation and deformation in the crack tip region of the corroded steel plates, the crack initiation criteria for the existing crack defects of the corroded steel plates could be established, and the fracture loads of the corroded steel plates with cracks could be better calculated.