Experimental and numerical validation of an inter-ply friction model for thermoset based fibre metal laminate under hot-pressing conditions

Hot-pressing can be an attractive fabrication method that enables the forming of hybrid materials like thermoset based fibre metal laminates. However, the process simulation on press forming requires accurate material characterization and boundary conditions to facilitate part design for a defect-free component. In order to improve the overall...

A methodology to predict the static strength of bolted joints in Fibre Metal Laminates

Joining structural components in aircraft is generally performed through mechanical fastening. The interaction of bearing and bypass stresses in composite bolted joints causes a reduction in the static strength of the joint. The bearing-bypass diagram determines the bearing and net-section failure modes. This thesis work aims to provide a design...

The mechanical effects of kissing bonding defects in hybrid metal-composite laminates

Fibre metal laminates (FML) are hybrid materials perspective for wind-turbine, containers and marine objects, besides the aerospace industry. During the manufacturing process some faults can occur and can be hazardous for the reliability of FML structures. One of the most critical defects are kissing bonding due to their lack of detectability...

Prediction of Fatigue Crack Growth and Damage Directionality in Non-Conventional Fibre Metal Laminates

This thesis presents a model that is able to predict fatigue crack growth and damage directionality in non-conventional Fibre Metal Laminates (FMLs) in CentreCracked Tension (CCT) specimens. Non-conventional FMLs encompass all FMLs other than standardised ones such as GLARE. FMLs can be made non-conventional by using multiple fibre types, any...

Methodology for Bearing-Bypass Testing in Fibre Metal Laminates

Bearing-bypass behaviour for composites is different than for metals and therefore this behaviour needs to be re-evaluated. This thesis work aims to provide an initial test set-up to map the bearing- and bypass behaviour in Fibre Metal Laminate mechanical joints, to develop a simple method which can be used by engineers for joint design. This...

Alternative Manufacturing Route of Fibre Metal Laminates

Fibre metal laminates (FML) are manufactured by stacking metal sheets and fibre reinforced prepreg in an alternating fashion, and curing it in an autoclave. The most well-known FML is Glare, which has been successfully applied on Airbus A380 for its fuselage skin. It consists of aluminium sheets and glass fibre prepregs. FMLs have a better...

Investigation of the low velocity impact on advanced hybrid laminates: Improving the impact resistance of CFRP laminates by embedding metal constituents

Composites have been widely applied in current aerospace structures. In spite of various advantages that composites have, the sensitivity to the impact damage for the composite materials has become a severe threat to the structural integrity of aerospace structures. Therefore, this research work focuses on embedding metal layers in the composite...

Conceptual Design of Fibre Metal Laminate Fuselage Panels

With improvements in aviation technology, design requirements to be full-filled have also increased exponentially. This in turn influences the complexity of design process, along with the time and effort required for it. The problem, for this research, has been set up with respect to challenges faced at Fokker Aerostructures, during in-proposal...

Methods of Improving the Post Shear-Buckled Stiffness of Glare

The influence of the Transition Zone on the structural behavior of pin connected areas in local metal reinforced composites

Fibre Metal Laminates (FML) are hybrid composites, with the attempt to combine the advantages of metals and fibre reinforced plastics. Their promising properties are used locally in joining areas to reduce the structural weight. As the metal foils density, in this case a steel alloy, is much higher than the density of carbon plies, its amount...

Friction Stir Welding effects of defects in Glare

Splicing technology is used to create fuselage panels due to the maximum width of the aluminium sheets of 60 inches as a result of the production process. A set of designing rules is required for the design of a spliced Glare fuselage resulting in a significant increase in complexity. Friction stir welding of the thin aluminium sheets in Glare...

A simplified method for the determination of damage arrest capabilities in stiffened structures

The recent application of Glass Reinforced Aluminium (Glare) in the Airbus A380 has proven to be a suitable candidate to replace metal structures. The reduction in weight and increased performance results in lower emissions and cost reduction. Therefore research has been performed at the Delft University of Technology, dedicated to the residual...

Predicting fatigue crack initiation and propagation in Glare reinforced frames

The most highly loaded frames of the newly developed Airbus A400M transport aircraft have glass reinforced aluminium laminate (Glare) straps attached to them to increase their resistance to fatigue damage. These straps were designed using static strength requirements for the frame. Basic justification was done in two steps. Firstly, the frame...

Fatigue Crack Growth Prediction for generalized fiber metal laminates and hybrid materials

The excellent durability performance of Glare, a thin fiber metal laminate (FML) material system, is now being proven in service. This has motivated work towards the application of FMLs to thicker structures driven by damage tolerance. In order to fully characterize the crack growth life of such materials, models are necessary that can account...

Damage evolution in GLARE fibre-metal laminate under repeated low-velocity impact tests

An experimental study was performed on the repeated low-velocity impact behaviour of GLARE. Damage evolution in the material constituents was characterised with successive number of impacts. Records were correlated with visual inspection, ultrasound C-scan and chemical etching. The stiffness of the plate varied when cumulating the number of...

Forming of Laminates

Fibre-Metal-Laminates have excellent properties for aerospace applications, with GLARE as an example. The metal layers inside the laminate provide permanent plastic deformations for the whole laminate; in principle Fibre-Metal-Laminates can be formed with common sheet metal forming processes. The difference between monolithic sheet metal and...