Correlation between quasi-static and dynamic crack resistance curves

Abstract

The correlation between the crack resistance measured from dynamic and quasi-static J–R tests has been investigated based on test data from instrumented Charpy impact tests and quasi-static single edge notched bend (SENB) J–R tests. The method originally proposed by Aurich et al. [Analyse und Weiterentwicklung Bruchmechanischer versagenskonzepte––Lokales Risswachstum, Ermittlung des Risswiderstandsverhaltens aus der Kerbslagarbeit. BAM Forschungsbericht 192, Berlin 1993, ISBN 3-89429-329-2], to develop a correlation coefficient between the net fracture resistance of Charpy V-notch (ISO) and quasi-static compact tension tests, was extended to establish correlations between so-called ductile–brittle transition fracture resistance curves obtained from instrumented Charpy V-notched (ISO) and fatigue precracked impact tests and quasi-static SENB J–R fracture resistance tests. The correlation between the dynamic and quasi-static crack resistance with regard to practical application to fracture assessments appears to be reasonably consistent, bearing in mind the inherent scatter in crack resistance data in general. The findings of the present research project from testing of ship grade NVE 36 and pressure vessel steel to ASTM A516 Gr. 70 as well as two weldments in the NVE 36 steel, are in excellent agreement with the results of the research conducted by Aurich et al. [Analyse und Weiterentwicklung Bruchmechanischer versagenskonzepte––Lokales Risswachstum, Ermittlung des Risswiderstandsverhaltens aus der Kerbslagarbeit. BAM Forschungsbericht 192, Berlin 1993, ISBN 3-89429-329-2] for structural and pressure vessel steels to the German DIN standard steels including St 52-3, StE 355 and StE 460.