A method for 3D simulation of internal gas effects on thermal-mechanical behaviors in nuclear fuel elements

A new method for three-dimensional simulation of the interaction between the gas and the solid around is developed. The effects of the gas on the thermal-mechanical behaviors within the surrounded solid are performed by replacing the internal gas with an equivalent solid in the modeling, which can make it convenient to simulate the thermal-mechanical coupling effects in the solid research objects with gases in them. The applied thermal expansion coefficient, Young＇s modulus and Poisson＇s ratio of the equivalent solid material are derived. A series of tests have been conducted; and the proposed equivalent solid method to simulate the gas effects is validated.