Aerospace damage tolerance requires that a part will not grow a crack of critical size, in this case leading to a fuel leak within the duration of the maintenance interval. It was required to assess the damage tolerance of an aerospace flight component where fuel was circulated in the base of the component to cool the electronics. The challenge was to determine that a crack would not grow to a critical size which would lead to a fuel leak within the duration of the maintenance interval.
Hamilton Sundstrand utilized the BEASY 3D Crack Growth analysis capabilities to study crack growth rates and directions in the aerospace flight component. The BEASY model enabled the fracture mechanics study to be performed on the actual 3D hardware thereby eliminating the need for crude 2D Approximations. The analysis process starts with the most conservative approach and if required to less and less conservative analysis. This starts with the calculation of a stress intensity factor, then use of generic crack growth analysis using solutions like NASGRO. Finally, BEASY crack growth simulation was used to ensure the part met the damage tolerant requirements, with the least conservative approach. The BEASY solution enables the engineer to quickly extract the local area of interest, setup the analysis including the creation of an initial crack, and then solve and post process the results.
Using the most specific and least conservative crack growth approach, Hamilton Sundstrand was able to demonstrate the in service the controller would not grow a crack able to leak fuel between service intervals without having to redesign the controller.
The outcome was assessed to be a significant improvement over previous less sophisticated methods used in fracture mechanics.