Correlations between fracture toughness and small-scale test results are useful in pressure vessel applications due to cost, availability of material, and ease of testing. The material parameter, fracture toughness, can be used directly in design analysis. The small-scale test results, which are not designed to provide the information necessary to predict a failure load or critical flaw size, may provide this information through correlation with the fracture toughness. Possible small-scale tests for this type of relationship include the Charpy test, the nil-ductility transition temperature test, and the dynamic tear test. Correlations of Charpy test results for the upper shelf region and three types of transition region correlations are evaluated. When evaluating the proposed correlations, it is important to consider the effects of notch acuity and strain rate. The effects of plate position and scatter of the experimental results are also noted. Due to the empirical nature of the correlations, no one correlation can be shown to be more accurate for all materials. The materials reviewed are steels with yield strengths between 250 and 760 MPa (36 and 110 ksi). A correlation developed for a material under consideration is obviously preferred. When such a correlation is not available, the authors have recommended correlations likely to give conservative results.
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Published: 1981 Number of Pages: 24 File Size: 1 file , 840 KB