Investigation of GLARE 2 as Titanium replacement for fuselage crack stoppers

The Fibre Metal Laminates (FML) concept is established on Airbus aircraft, especially since its grade GLARE has been applied in significant volume at the fuselage and empennage of the Airbus A380, as well as local reinforcements at the A400M.

GLARE was developed primarily to enhance the fatigue resistance capabilities of aluminium alloys. Due to its layered configuration (alternating layers of metal and fibre composites with different fibre orientations); FML can be optimized to specific applications.

Airbus aircraft apply titanium crack stoppers at its longitudinal riveted joints in aluminium fuselage structures to enhance its damage tolerance capabilities and to improve the inspect ability of hidden cracks. The presentation will elaborate on this aspect in further detail and clarify the usage of the titanium material for crack stoppers.

Titanium alloys has a lot of advantages over aluminium alloys, of which its higher stiffness is one of great importance. However, aside of its advantages titanium alloys has also disadvantages, which are performance, manufacturability as well as cost related. The presentation will discuss these aspects briefly in further detail.

GLARE has advantages which address the specific disadvantages of Titanium alloys. However, in its standard grades GLARE does not meet the specific performances of Titanium alloys as is required for crack stopper application. Therefore the laminate needs to be optimized to meet these requirements. The presentation will discuss the development of the optimized GLARE material, its basic properties and will show by full scale test that the selected configuration meets all requirements for fuselage damage tolerance applications