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The purpose of this paper is to study the deterministic elastic buckling behavior of cylindrical fiber–metal laminate panels subjected to uniaxial compressive loading and the investigation of GLAss fiber-REinforced aluminum laminate (GLARE) panels using probabilistic finite element method (FEM) analysis.

The FEM in combination with the eigenvalue buckling analysis is used for the construction of buckling coefficient–curvature parameter diagrams of seven fiber–metal laminate grades, three glass-fiber composites and monolithic 2024-T3 aluminum. The influences of uncertainties concerning material properties and laminate dimensions on the buckling load are studied with sensitivity analyses.

It is found that aluminum has a stronger impact on the buckling behavior of the fiber–metal laminate panels than their constituent uni-directional or woven composites. For the classical simply supported boundary conditions, it is found that there is an approximately linear relation between the buckling coefficient and the curvature parameter when the diagrams are plotted in double logarithmic scale. The probabilistic calculations demonstrate that there is a considerable probability to overestimate the buckling load of GLARE panels with deterministic calculations.

In this study, the deterministic and probabilistic buckling response of fiber metal laminate panels is investigated. It is shown that realistic structural uncertainties could substantially affect the buckling strength of aerospace components.

This study aims to demonstrate the numerical application of differential quadrature (DQ) methods and show the experimental application of free vibration analysis of fiber-metal laminated composite (FML) plates with various boundary conditions.

The FMLs are hybrid structures consisting of fiber-reinforced polymer matrix composites such as carbon, glass, aramid and different metal sheets, and are currently widely used in the automobile, aircraft and aerospace industries. Thus, free vibration analysis of these hybrid materials is necessary for the design process. The governing equations of motion are derived based on the classical plate theory. The DQ, generalized DQ (GDQ) and harmonic DQ (HDQ) differential quadrature methods have been used to solve the governing equations of an FML composite plate numerically. The accuracy and convergence of the numerical model have been verified by comparing the results available in the published literature with the results obtained from these methods. Moreover, an experimental procedure has been performed in order to compare the results against those of the numerical methods.

It is noteworthy that a high degree of similarity and accuracy was observed between the numerical results obtained by the DQ methods and the experimental results. Thus, the present study validates the applicability of the DQ methods for designing the FML composite plates.

In this study, the advantages of the DQ methods have been demonstrated differently from previous studies on the vibration analysis of the FML plates.

The purpose of this paper was to compare the response of selected hybrid Fibre Metal Laminates (FMLs) in the form of glass and carbon fibre aluminium laminates to dynamic and static loads compared together.

The subject of examination was FMLs (Al/CFRP and Al/GFRP). The samples were subjected to low-velocity impact and quasi-static indentation. The response of laminates to the both types of loads was evaluated by comparison of force – displacement diagrams including the values of maximum forces as well as the extent and nature of structure degradation as a result of loads.

In case of Al/GFRP laminates, the analysis of characteristic relations, i.e. force – displacement and the impactor influence area in case of indentation and impact confirmed that certain parameters, i.e. the values of maximum force transferred by laminate, destruction surface area and destruction mechanisms are consistent after static and dynamic tests. Significant differences were found in destruction scale in Al/GFRP laminates despite considerable fitting of force – displacement diagrams to static and dynamic tests. Destruction surface area observed in FML carbon laminates subjected to dynamic loads was significantly smaller than after indentation but perforation area occurring at the unloaded side was much more extensive.

Research issues in the scope of dynamic loads by means of concentrated force in composite materials and interpretation of the effects of their impacts are extremely complex. Therefore, the attempts are made to predict the resistance to dynamic loads by means of concentrated force using statistical research methods. The test results might be useful for the design and simulations of FMLs applications in aerospace.

From the analysis of available literature, it appears that there are no studies exploring the issue of forecasting or comparison the effects of static and dynamic tests for hybrid FMLs. The new hybrid materials like FMLs have different mechanisms of damage initiation and propagation as a result of impact, in comparison to classic composite materials. It means that possibilities of using the static loads to predict impact resistance should be known well for all type of FMLs. Actually, there is no research about static indentation in relation to low-velocity impact of aluminium-carbon laminates. This situation encouraged the authors of the present study to undertake research in this scope. The results can demonstrate and explain why prediction of impact resistance of FMLs by using static indentation is uncertain and not always valuable.

The purpose of this study was to carry out the analysis of impact resistance for aluminum hybrid laminates and polymer matrix composites reinforced with glass and carbon fibers. Damage modes and damages process under varied impact energies are also presented and discussed.

The subject of examination were fiber metal laminates – FMLs (Al/CFRP and Al/GFRP). The samples were subjected to low-velocity impact by using a drop-weight impact tester. The specimens after impact were examined using non-destructive and destructive inspection techniques.

The hybrid laminates are characterized by higher resistance to impact in comparison to the conventional laminates. The delaminations between composite layers as well as the delaminations on metal/composite interface and lateral cracks are the prevailing type of destruction mechanisms. No significant relationships between metal volume friction coefficient vs response to the impact were recorded for the hybrid laminates under tests.

The understanding of impact behavior of FMLs is particularly important for selecting these materials and their designing, in damage tolerance philosophy aspect in aerospace industry as well as in searching the methods of predicting of FML hybrid materials resistance to impact. The test results might be useful for the validation of simulations using numerical methods.

The paper presents the impact resistance of new hybrid laminates for aerospace applications. The identification of damage character and failure mechanisms as well as the relationships between damage and impact responses of aluminum/carbon and aluminum/glass hybrid laminates were estimated.

The purpose of this paper is to use numerical methods early in the airframe design process and access the structural performance of wing leading edge devices made of different materials and design details, under bird strike events.

Explicit finite element analysis was used to numerically model bird strike events.

Structural performance charts related to materials and general design details were drawn to explore the design space dictated by the current applicable airworthiness requirements.

This paper makes use of the current capability in the numerical tools available for structural simulations and exposes the existing limitations in the terms of material modelling, material properties and fracture simulation using continuum damage mechanics. Such results will always be in the need of fine-tuning with experimental testing, yet the tools can shed some light very early in the design process in a relative inexpensive manner, especially for design details down selection like materials to use, structural thicknesses and even design arrangements.

Bird strike simulations have been successfully used on aircraft design, mainly at the manufactured articles design validation, testing and certification. This paper presents a hypothetical early design case study of leading edge devices for appropriate material and skin thickness down selection.

The purpose of this paper is to develop a mathematical model for delamination during drilling by using a response surface methodology (RSM) and also to determine how the input parameters (tool diameter, spindle speed and feed rate) influence the output response (delamination) in machining of fiber metal laminates.

Three factors and a three-level central composite design in RSM are used to carry out the experimental investigation. A video measuring system is used to measure the width of maximum damage of the machined FML composite. The “Design Expert 7.0” is used to analyze the data collected graphically. Analysis of variance is carried out to validate the model and for determining the most significant parameter.

The response surface model is used to predict the input factors influencing the delamination on the machined surfaces of the ARALL composite at different cutting conditions with the chosen range of 95 percent confidence intervals. Analysis of the influences of entire individual input machining parameters on the delamination has been carried out using RSM.

The effect of delamination on drilling of ARALL composites with solid carbide tools of various diameters has not been analyzed yet using RSM.

The purpose of this paper is to predict the response and perforation of fibre metal laminates (FMLs) subjected to impact by projectiles at different velocities.

A finite element (FE) model is constructed in which recently proposed dynamic constitutive models for fibre reinforced plastic (FRP) laminates and metals are used. Moreover, a recently developed dynamic cohesive element constitutive model is also used to simulate the debonding between FRP laminates and metal sheets. The FE model is first validated against the test data for glass laminate aluminum reinforced epoxy (GLARE) both under dropped object loading and ballistic impact, then used to perform a parametric study on the influence of projectile nose shape on the perforation of FMLs.

It is found that the present model predicts well the response and perforation of GLARE subjected to impact loading in terms of load-time history, load-displacement curve, residual velocity and failure pattern. It is also found that projectile nose shape has a considerable effect on the perforation of GLARE FMLs and that the ballistic limit is the highest for a flat-ended projectile whilst for a conical-nosed missile the resistance to perforation is the least.

Recently developed constitutive models for FRPs and metals, together with cohesive element model which considers strain rate effect, are used in the FE model to predict the behaviour of FMLs struck by projectiles in a wider range of impact velocities; the present model is advantageous over such existing models as Johnson-Cook (JC) + Chang-Chang and JC (+BW) + MAT162 in terms of failure pattern though they produce similar results for residual velocity.

The purpose of this paper is to investigate the ballistic impact response of square clamped fiber-metal laminates and monolithic plates consisting of different metal alloys using the ANSYS LS-DYNA explicit nonlinear analysis software. The panels are subjected to central normal high velocity ballistic impact by a cylindrical projectile.

Using validated finite element models, the influence of the constituent metal alloy on the ballistic resistance of the fiber-metal laminates and the monolithic plates is studied. Six steel alloys are examined, namely, 304 stainless steel, 1010, 1080, 4340, A36 steel and DP 590 dual phase steel. A comparison with the response of GLAss REinforced plates is also implemented.

It is found that the ballistic limits of the panels can be substantially affected by the constituent alloy. The stainless steel based panels offer the highest ballistic resistance followed by the A36 steel based panels which in turn have higher ballistic resistance than the 2024-T3 aluminum based panels. The A36 steel based panels have higher ballistic limit than the 1010 steel based panels which in turn have higher ballistic limit than the 1080 steel based panels. The behavior of characteristic impact variables such as the impact load, the absorbed impact energy and the projectile’s displacement during the ballistic impact phenomenon is analyzed.

The ballistic resistance of the aforementioned steel fiber-metal laminates has not been studied previously. This study contributes to the scientific knowledge concerning the impact response of steel-based fiber-metal laminates and to the construction of impact resistant structures.

The purpose of the study was to develop the forming methodology for FML laminates with complex shapes, based on aluminium and epoxy-glass composite.

The subject of research encompassed Al/GFRP fibre metal laminates. Autoclave process has been selected for FML profiles production. The manufacturing process was followed by quality analysis for laminates produced.

The achievement of high stability and dimensional tolerance of thin-walled FML laminates is ensured by developed technology. The values of selected sections angles are significantly limited as a result of forming of FML laminates through the components performing. Failure to adhere to technological recommendations and to high regime of developer technology may lead to the occurrence of defects in FML.

Thin-walled composite structures could be applied in light-weight constructions, such as aircraft structures, which must meet rigorous requirements with regard to operation under complex load. The development of this type of technology may contribute to increased importance of FML sections in research area and finally to increased scope of their applications.

The production of thin-walled FML profiles with complex geometry, which would be characterized by dimensional stability and repeatable structural quality free of defects, is associated with many problems. No studies have been published so far on an effective forming process for FML laminates with complex shapes. Developed methodology has been verified through quality evaluation of produced profiles by means of non-destructive and destructive methods. The development of this type of technology may contribute to increased importance of FML, e.g. in aerospace technology.

Fibre metal laminates were developed at Delft University during the last two decades as a family of new hybrid materials consisting of bonded thin metal sheets and fibre/adhesive layers. This laminated structure provides the material with excellent fatigue, impact and damage tolerance characteristics and a low density. While the 20 per cent weight reduction was the prime driver behind the development of this new family of materials, it turns out that additional benefits like cost reduction and an improved safety level have become more and more important. The combination of these aspects in one material makes fibre metal laminates a strong candidate material for fuselage skin structures of the new generation of high capacity aircraft. The focus on this application currently leads to industrialization and qualification that makes this material available to the aircraft designer.