Berücksichtigung der Dehnungsbehinderung in bruchmechanischen Sicherheitsanalysen

In integrity assessments for structures containing defects fracture mechanics based approaches are required. Therefore, besides the need to imply all parameters contributing to the stressing it is essential to characterise the resistance. Concerning upper shelf behaviour and ductile crack initiation, a physical as well as a technical characteristic value of the critical crack tip loading J can be employed. But, as the stress-state is changing due to crack growth there is a certain influence on the result of the fracture mechanics test. Whether the toughness value determined with a laboratory-size specimen may be assigned to a structure can be verified by constraint theory. Within a testing series of fracture mechanics tests as well as a component test implying two different steels, the transferability is approved by considering the specific stress state. Furthermore it is proven that taking the constraint into account is a crucial point, particularly for semi-elliptical crack configurations

Berücksichtigung der Dehnungsbehinderung in bruchmechanischen Sicherheitsanalysen

In integrity assessments for structures containing defects fracture mechanics based approaches are required. Therefore, besides the need to imply all parameters contributing to the stressing it is essential to characterise the resistance. Concerning upper shelf behaviour and ductile crack initiation, a physical as well as a technical characteristic value of the critical crack tip loading J can be employed. But, as the stress-state is changing due to crack growth there is a certain influence on the result of the fracture mechanics test. Whether the toughness value determined with a laboratory-size specimen may be assigned to a structure can be verified by constraint theory. Within a testing series of fracture mechanics tests as well as a component test implying two different steels, the transferability is approved by considering the specific stress state. Furthermore it is proven that taking the constraint into account is a crucial point, particularly for semi-elliptical crack configurations