INVESTIGATING THE INFLUENCE OF FLUID-STRUCTURE INTERACTION ON LEAK-BEFORE-BREAK ANALYSES WITH A NEW FINITE ELEMENT METHOD

This paper describes a new finite element method to analyse Leak-before-Break using the extended finite element method (XFEM). Traditionally, a Leak-before-Break analysis is performed using a methodology outlined in a Structural Integrity Assessment Procedure such as R6. This may achieve sufficient accuracy for the application of interest. However; there may be times when finite element (FE) analysis is required. With this in mind, a finite element model has been developed in which all the physics of the crack and leak rate is bundled into a special element, with only the crack size and position, external loads and fluid properties required as an input. All the meshing and leak rate calculation is dealt with by the code. This means that Leak-before-Break procedures can be performed more efficiently, even if FE modelling is required. The element was implemented in MATLAB and then used to investigate the rmo-mechanical behaviour of a leaking thermo-fluid in a plate. For bulk fluid temperatures 20 degrees C hotter than the structure, it was found that the leak rate was reduced by 40% due to crack closure.