ABSTRACT
Embedding heater elements in GLARE laminates makes it to a multipurpose material and enables the design of heated leading edges without additional substructures in the wings (FMLC 2015). Thus, heated GLARE shows weight saving potential as no bleed air systems for circulating hot air in the leading edges or structures for pneumatic de-icing have to be added in the wing structure. Electrically powered embedded heater elements used for anti-or de-icing follow current trends towards electric aircraft and multipurpose materials (Mohseni & Amirfazli 2013). Figure 1 shows the cross-section of the GLARE 5-4/3-0.3 layup with an embedded heater element between the UD layers, as used in this study. In addition to residual stresses formed in the curing process (Abouhamzeh et al. 2015), a (local) temperature increase causes strains and stresses in the laminate material due to different thermal expansion coefficients
1 INTRODUCTION
The development of Fiber Metal Laminates (FMLs) such as GLARE has been a field of research since decades (Vlot & Gunnink 2001, Sinmazcelik et al. 2011). GLARE is the acronym of glass fiber rein-forced aluminum laminate and is a certified laminate material composed of alternating layers of alumi-num and S-2 fiber glass prepregs (Vlot 2001). The S-2 fiber glass prepregs are unidirectional (UD) layers. GLARE is currently used in the fuselage of the A380 (Hagenbeek 2005). The benefits of using GLARE are a lower fatigue crack growth rate com-pared to monolithic aluminum (Alderliesten & Homan 2006), a better strength bearing capability in combination with favorable impact and lightening resistance (Vlot & Gunnink 2001, Vermeeren 2002) and better UV-and moisture-resistance compared to pure glass fiber laminates (Park et al. 2010). Those features make GLARE to a favourable material to design damage tolerant parts (Alderliesten & Homan 2006).
