Functional failure criterion based on biaxial tensile testing of steel liners and its application to fragility analysis of nuclear containment under overpressure conditions

To investigate the mechanical behavior of the steel liner under bi-directional tensile loading, 39 cruciform tensile specimens made of P265GH steel liner are examined by biaxial tensile tests with different loading ratios. Based on the strength theory of materials and test results, an anisotropic tearing criterion for the steel liner is established. Subsequently, the proposed tearing criterion is applied to the fragility analysis of the containment under overpressure conditions. Finally, the differences between the proposed and existing tearing criteria are discussed. The results show that the strength of the steel liner under biaxial tensile loading is improved, while the deformation capacity is significantly decreased. The proposed tearing criterion is more consistent with the actual behavior of steel liners under bi-directional tensile loading. When evaluating the probabilistic performance of the containment, it is more practical and safer to predict the functional failure of the containment by using the proposed tearing criterion.