| Abstract: | The failure behaviour of cracked components can be described sufficiently precisely and assessed conservatively using fracture mechanics based methods within their limits of application. Depending on the chosen procedure rather different results can be obtained concerning the accuracy reaching from relatively rough estimations up to very exact assessments. Toughness requirements can be specified quantitatively for cracked components reversing the conventional fracture-mechanics analysis. The required toughness values depend on the component and defect geometry, the strength of the material and the safety criterion. The presented examples have revealed that for realistic defect sizes the material toughness of low-strength steels shows a much higher level than required, whereas in case of higher strength steels the margin between requirements and properties may become small. |
