Effects of damage evolution on tensile strength measurement of nuclear graphite material by ring compression test

Abstract

• Effects of damage evolution on tensile strength measurements were studied. • Damage evolution should be considered if an indirect method is used for strength measurement. • Uniaxial tensile strength can be measured via the diametrical ring compression test. Because of the limitations of the direct tension method, indirect methods such as Brazil tests or ring compression tests are widely applied to measure the tensile strength of brittle materials. However, in most cases of indirect method application, empirical equations that have been derived based on the assumption of a linear elastic material are used, and the effects of damage on the tensile strength measurements are ignored. Thus, in this study, ring-shaped nuclear graphite IG-11 specimens were subjected to diametrical compression tests to study the effects of damage evolution on tensile strength measurements. By analysing the experimental results and the damage evolution law obtained via an inverse method and finite element analysis, the true uniaxial tensile strength of IG-11 was accurately obtained. The results indicate that damage plays an important role in the tensile strength measurement of the nuclear graphite material when an indirect method is used. This study is also useful as a reference for obtaining accurate tensile strength predictions for other types of brittle materials.