Experimental and numerical investigation of ply size effects of steel foil reinforced composites

The effect of ply thickness on the notch sensitivity and bearing properties on carbon fibre reinforced polymer composites and their hybrid laminates with steel foils were studied. Laminates with ply thicknesses of 0.3 mm and 0.03 mm comprising of CFRP and hybrid laminates were manufactured and characterized using tension, open hole tension...

Fatigue in fibre metal laminates: The interplay between fatigue in metals and fatigue in composites

With the introduction of fibre metal laminates (FMLs) as a (fatigue) damage tolerant material concept in aeronautics, an interesting field emerged where fatigue damage interaction plays a dominant role. The hybrid concept effectively demands evaluating fatigue damage growth based on fracture phenomena typical for both metals and fibre...

On the physics of applying finite width and geometry correction factors in fatigue crack growth predictions of GLARE

In general, a finite width correction to stress intensity factor (SIF) is required in the fatigue crack growth. The finite width correction factor can be explained physically from the energy point of view. It is assumed that the finite width correction factor primarily constitutes an energy correction factor, i.e. it corrects the applied load...

Theoretical analysis of fatigue failure in mechanically fastened Fibre Metal Laminate joints containing multiple cracks

Mechanically fastened joints are susceptible to the presence of multiple-site damage (MSD) cracks in the critical fastener row. Different from the MSD growth in joints consisting of metallic substrates, the two coupled metal crack growth and interfacial delamination propagation failure mechanisms in Fibre Metal Laminates (FMLs) make the...

Detection and Evaluation of Pre-Preg Gaps and Overlaps in Glare Laminates

Gaps and overlaps between pre-preg plies represent common flaws in composite materials that can be introduced easily in an automated fibre placement manufacturing process and are potentially detrimental for the mechanical performances of the final laminates. Whereas gaps and overlaps have been addressed for full composite material, the topic...

The Challenge of Reversing Theories to Hybridize Structures with Fiber Metal Laminate Design Concepts

To further optimize aeronautical structures, an increased level of material hybridization is required. Optimization efforts aim to identify optimal design solutions that satisfy prescribed requirements. However, this demands reversal of currently available knowledge on hybrid structural technologies, which are often formulated as theories...

Analysis of thermal strains and stresses in heated fibre metal laminates

Current trends in aircraft design are to increase the economic efficiency by integrating different features in multifunctional materials. One strategy is to embed resistance heater elements between glass-fibre epoxy layers in (heated) fibre metal laminates and to use them as anti or de-icing devices in leading edges of wings. Heated glass...

Effect of prepreg gaps and overlaps on mechanical properties of fibre metal laminates

During the automated manufacturing of fibre reinforced laminates, defects can be produced. Gaps and overlaps between adjacent prepreg layers can be produced in composites during the tape-layup process. However, the topic is not yet studied for hybrid materials, in which metal sheets and thin prepreg layers lead to different effects due to the...

Analytical prediction model for non-symmetric fatigue crack growth in Fibre Metal Laminates

This paper proposes an analytical model for predicting the non-symmetric crack growth and accompanying delamination growth in FMLs. The general approach of this model applies Linear Elastic Fracture Mechanics, the principle of superposition, and displacement compatibility based on the understanding of deformation behaviour in eccentrically...

Out-of-autoclave manufacturing of GLARE panels using resistance heating

Autoclave manufacturing of fibre metal laminates, such as GLARE, is an expensive process.Therefore, there is an increasing interest to find cost effective out-of-autoclave manufacturing processes without diminishing the laminate quality. The aim of this study is to evaluate the quality of fibre metal laminate...

An experimental investigation into pin loading effects on fatigue crack growth in Fibre Metal Laminates

This paper provides an experimental investigation into the pin loading effects on the crack growth behaviour in Fibre Metal Laminates. The pin loading effects and bypass loading effects are incorporated in two different tested joints. The analysis of the test results shows that pin loading dominates the crack growth only in the vicinity of the...

Degradation Behavior of Epoxy Resins in Fibre Metal Laminates Under Thermal Conditions

GLARE (glass fibre/epoxy reinforced aluminum laminate) is a member of the fiber metal laminate (FML) family, and is built up of alternating metal and fiber layers. About 500m2 GLARE is employed in each Airbus A380 because of the superior mechanical properties over the monolithic aluminum alloys, such as weight reduction, improved damage...

Numerical assessment of failure mechanisms in fibre metal laminates

In this contribution numerical models are discussed for describing failure mechanisms in fibre metal laminates. Fibre metal laminates form a new class of materials which are considered for a possible application to the fuselage of future aircraft generations. The intensive experimental analyses of these materials are focused on the assessment of...

Finite element procedure for modelling fibre metal laminates