A modified continuum damage model considering cryogenic temperatures and its application in corrugated plates of the LNG membrane storage tank

The primary barrier system of LNG (liquid natural gas) membrane storage tank is a critical component, comprising corrugated plates made of austenitic stainless steel (ASS). Although many experiments show that the nonlinear behaviours of ASS during plastic deformation can significantly be affected by the temperature and strain, the conventional damage constitutive models are often inadequate to accurately characterize mechanical properties of complicated structures, particularly at cryogenic temperatures. In the present study, a modified Lemaitre damage constitutive model is developed on the 304L stainless steel, where the phase transition has been incorporated. First, the stress-strain curve for the 304L stainless steel within the range of 108-293 K are obtained based on the loading and unloading experiments. Subsequently, a modified model is proposed in combination with the Olson-Cohen phase transition model. The consistency between the experimental and simulation results is evaluated using the vumat subroutine implemented by the finite element method. Finally, the modified model is employed to analyze the damage of corrugated plates subjected to dynamic loading at various temperatures. The results show that the modified model is potential in designing and accurately assessing the safety of ASS structures at cryogenic temperatures.