A review: Fibre metal laminates, background, bonding types and applied test methods

Impact resistance of fiber-metal laminates: A review

Behaviour of fibre–metal laminates subjected to localised blast loading: Part I—Experimental observations

Fiber metal laminates (FMLs) are layered materials based on stacked arrangements of aluminum alloy layers and fiber reinforced plastic (FRP) layers. FMLs have benefits over both aluminum and fiber reinforced composites. In this work, glass fibers and Kevlar fibers are used together and effect of fibers orientation on tensile behavior of this novel material is investigated. A modified classical laminate theory (CLT), which considers the elastic–plastic behavior of the aluminum sheets, and a numerical simulation method based on finite element modeling (FEM) are used to predict the stress–strain response of FMLs. Specimens were made and mechanical testing was performed to determine in-plane tensile properties of this type of FMLs. Good agreement is obtained between the models predictions and experimental results. Test results show that fiber sheets with zero orientation in laminate improve modulus of elasticity, yield stress and ultimate tensile stress considerably. Statistical analysis of data is done and an estimated response surface of ultimate tensile strength of the specimens as a function of fiber orientation in each layer is obtained. Also, the effect of the independent variables and interactions with their relative significance on the tensile behavior is specified. It is shown that Kevlar fiber orientation is the most important parameter between all variables and their interactions.

A study on tensile properties of a novel fiber/metal laminates

Simulation of the response of fibre–metal laminates to localised blast loading

Behaviour of fibre metal laminates subjected to localised blast loading—Part II: Quantitative analysis

Failure characterisation of blast-loaded fibre–metal laminate panels based on aluminium and glass–fibre reinforced polypropylene

The main aim of the work reported in this paper was to assess the reponse of panels representative of aircraft structures, to pulse pressure loading by means of experimental and finite element (FE) techniques. A series of experiments were conducted to compare the responses and failure modes of stiffened, aluminium alloy panels, joined using conventional riveting techniques and laser welding. The failure pressures of the riveted panels ranged from 29 to 36 kPa and a number of principal modes of failure were identified, namely (1) rivet shear/tensile failure, (2) frame buckling, (3) stringer buckling and (4) frame rupture. In the case of the laser-welded panels, failure pressures were between 28 and 33 kPa and failure was dominated by significant tearing along the weld heat affected zone at the frame–skin interface. The FE models correctly modelled most of the principal modes of failure observed experimentally and central panel displacement was also predicted well up until the time at which failure initiated.

Pulse pressure loading of aircraft structural panels

The paper presents some results from a study being undertaken at Liverpool into the application of laser welding technology to the design and fabrication of blast and impact resistant structures in the transportation industries. A novel facility has been developed at Liverpool for analysis of dynamic pressure loading of structures, such as aircraft fuselage panels. In the initial work to compare riveted and laser welded panels, the study has included experiments to lap weld AA2024-T3 sheet with both CO2 and YAG lasers, initial dynamic loading tests on a riveted panel, quasi-static and uniaxial tensile tests on laser welded and riveted AA2024-T3 specimens and FE modelling of the trial riveted structures under loading. In conclusion, more consistent weld penetration on lap joints of 1.6mm thick alloy were obtained with a 3.5kW Nd:YAG laser, than a CO2 laser of equivalent power. Initial tests on a riveted panel identified some boundary conditions and failure loads for future tests. Uniaxial tests on laser welded and riveted specimens of AA2024-T3 indicated that the laser-welded joints have higher strength per unit joint length than the riveted ones, but exhibit more brittle failure. For the initial test panel, failure under dynamic loading occurred at a peak pressure of only 0.6 bar. The FE models of the preliminary tests compare well with experiment, based on mid-panel displacement measurements, but need further development to account for weak points in the frames where the test panel eventually failed.The paper presents some results from a study being undertaken at Liverpool into the application of laser welding technology to the design and fabrication of blast and impact resistant structures in the transportation industries. A novel facility has been developed at Liverpool for analysis of dynamic pressure loading of structures, such as aircraft fuselage panels. In the initial work to compare riveted and laser welded panels, the study has included experiments to lap weld AA2024-T3 sheet with both CO2 and YAG lasers, initial dynamic loading tests on a riveted panel, quasi-static and uniaxial tensile tests on laser welded and riveted AA2024-T3 specimens and FE modelling of the trial riveted structures under loading. In conclusion, more consistent weld penetration on lap joints of 1.6mm thick alloy were obtained with a 3.5kW Nd:YAG laser, than a CO2 laser of equivalent power. Initial tests on a riveted panel identified some boundary conditions and failure loads for future tests. Uniaxial tests on laser we...

M.C. Simmons

Papers

Behaviour of fibre–metal laminates subjected to localised blast loading: Part I—Experimental observations

Behaviour of fibre metal laminates subjected to localised blast loading—Part II: Quantitative analysis

Failure characterisation of blast-loaded fibre–metal laminate panels based on aluminium and glass–fibre reinforced polypropylene

Pulse pressure loading of aircraft structural panels

Blast and impact resistance studies of laser welded and riveted panel structures