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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 the study is the evaluation of the efficiencies of a group of small Italian airports and the comparison with a set of transport heliports to show the difference in the productivity of the two types of infrastructures.

The methodology used for the evaluation is the data envelopment analysis (DEA).

The better performance of the heliports compared to the small inefficient airports.

This research is limited by the field of application and the weaknesses of the DEA methodology. However, it could be the first step for further works that will include more accurate models.

The study suggests the conversion of the small inefficient airports into heliports feeding traffic towards the major hubs. The use of helicopters to reach poor accessible areas represents an alternative mode of transport.

This is the first case of application of the DEA methodology to a group of heliports.

The purpose of this article is to determine if the level of recyclability of atomized Ti-6Al-4V powder, used as raw material in electron beam melting (EBM), is in compliance with aeronautical standards.

The adopted strategy for this study was to manufacture a series of builds in the EBM system recycling the same powder from build to build. Optimized EBM process parameters were used, as well as the common procedure of powder recycling for each build, to emulate real production conditions. The aim of the study is to confirm that the powder properties are kept within the range of chemical contents which complies with the aeronautical standards despite numerous reuses.

The conclusion of this study is that the EBM-processed Ti-6Al-4V powder properties are conserved in consecutive builds with recycled powder. This study shows that significant raw material can be saved by powder recycling since the powder quality is kept in range throughout consecutive builds, despite the working conditions of EBM.

The main two advantages of application of EBM in the aerospace sector are design freedom and reduction of buy-to-fly ratio. The design freedom enables the creation of lightweight structures, which can significantly reduce the fuel consumption, while the reduction of buy-to-fly ratio enables much material saving in manufacturing of aircraft parts.

The present study represents the first complete study on atomized Ti-6Al-4V powder processed in EBM which was made for the sake of aeronautical sector.

This paper aims to identify the parameters that influence the cost competitiveness of helicopter services for scheduled passenger transport on a regional area.

The approach used is based on an analysis of demand and on a bi-level model (modal split model – service supply optimization model) optimization. Performance optimization in the supply of helicopter transport services is obtained by a sensitivity analysis on the recognized cost factors.

The identification of the variation margins in the cost factors that might make an helicopter competitive for scheduled passenger services.

The inability to consider the totality of the helicopters today on the market due to lack of available data on their cost structure.

It is represented by the opportunity of the spread of the helicopter through the strengthening of the competitive position in relation to other transport modes for passenger transport services.

It is represented by the ability to provide air transport services less expensive on the routes that connect the mainland with small islands, especially during the months when the sea conditions do not allow the naval connection causing the insulation phenomenon.

Today, there is a lack of papers dealing with the issue of the performance of the helicopters from the point of view of the transport planner, considering what should be the characteristics of the aircraft to ensure performance to consistent designed services.

This paper aims to set up and assess a new method to collaboratively mature the requirements for engine development in a more efficient way during the preliminary design phase.

A collaborative process has been set up in which detailed information on the behaviour of designed engines has been integrated into the aircraft preliminary sizing process by means of surrogate modelling.

The engine surrogate model has been invoked as a black box from within the aircraft preliminary design optimisation loops. The surrogate model reduces the uncertainty of coarse-grain formulas and may result in more competitive aircraft and engine designs. The surrogate model has been integrated in a collaborative cross-organisational workflow between aircraft manufacturer, engine manufacturer and simulation service providers to prepare for its deployment in industrial preliminary design processes.

The new collaborative way of working between aircraft manufacturer, engine manufacturer and simulation service providers could contribute to remove time consuming rework cycles in early and later design stages within delivering the optimal aircraft-engine combination.

The assessed process, based on an innovative collaboration standard, provides the opportunity to introduce useful design iterations with much more enriched information than in the classical design process as performed today. Specifically, the application of an engine surrogate model is advantageous, as it allows for extensive trade-off studies on aircraft level because of the low computational effort, while the intellectual property of the engine manufacturer (the engine preliminary design process) is respected and kept in-house.

The purpose of this paper is to investigate the concept of new drill bit geometry adjusted to a given composite type. This paper explores the possibility of drilling in composites without negative effects such as: delamination, rapid tool wear, matrix burns, pulling out of fibers, etc.

Appropriate modification of drill bit geometries applied to composite materials include, among other things: modifications of point angles, reduction of chisel edge width, modification of drill margins and proper preparation of drill bit corners.

Description of tool geometry for drilling of different types of composites, in particular drilling in parts included free grain surfaces but also drilling at a different angle than 90°.

Geometrical details of the tool for drilling are depended on the type of composite.

Making of montage holes in parts made of composites without negative effects during drilling.

Analysis of the current state of knowledge shows that there are insufficient solutions in terms of new drill geometry for drilling of composites. Existing solutions do not guarantee adequate stability and repeatability of the cutting process. It is necessary to create new geometry drills permit the elimination of negative phenomena during drilling.

This study aims to develop an innovative actuator for improving the performance of future aircraft, by adapting the airfoil shape according to the flight conditions. The flap’s camber of a civil regional transportation aircraft’s trailing edge actuated and morphed with the use of shape memory alloys (SMA) actuator technology, instead of the conventional split flap mechanism is studied.

For the flap’s members sizing an efficient methodology is utilised based on finite element (FE) stress analysis combined to analytically formulated design criteria. A mechanical simulation within an FE approach simulated the performance of the moving rib, integrating both aerodynamic loads and SMA phenomenology, implementing Lagouda’s constitutive model. Aim of this numerical simulation is to provide guidelines for further development of the flap. A three-dimensional assembly of the flap is constructed to produce manufacturing drawing and to ensure that during its morphing no interference between the members occurrs. Eventually, the manufactured flap is integrated on a test rig and the experimental characterisations under no and static loads, and dynamic excitation are performed.

Experimental results showed that the rib’s SMA mechanism can adequate function under load providing satisfactory morphing capabilities.

The investigated approach is an internal into the flap mechanism based on the shape memory effect of thin wires. In the developed mechanism, SMA wires are attached to the wing structure, where they function as actuating elements.

The purpose of the present paper is to develop a new technology for producing magnesium alloy twin-rib aircraft brackets by the forging method.

An overall description of magnesium alloys is given, with particular emphasis placed on magnesium wrought alloys that are used in the aircraft industry. Methods for producing ribbed brackets are discussed and the location of these parts in aircraft structure is described. The forging process for producing AZ31 magnesium alloy twin-rib brackets was modelled numerically, and selected results of the simulations performed are presented. The simulation results were then verified under laboratory conditions using a three-slide forging press equipped with three movable working tools. It was assumed that the use of this machine would allow for obtaining twin-rib aircraft brackets with improved both functional and strength properties compared to the production methods used so far.

The results demonstrate that the method developed by the present authors permits the production of twin-rib brackets. Positive theoretical results and preliminary experimental results prove that it is justified that the research on magnesium alloys used in the aircraft industry be continued.

The production of twin-rib aircraft brackets from magnesium alloys by the technology developed by the present authors would lead to enhanced product quality with simultaneous reduction in production costs (reduced labour costs and material consumption as well as increased process efficiency). At present, magnesium alloy aircraft parts, mainly obtained from semi-finished products imported to Poland, are produced by casting and machining methods. They exhibit, however, much worse properties than elements produced by metal forming methods. In addition to that, the application of machining in the production of these part leads to higher production costs.

The originality of this study stems from the presentation of an innovative metal forming technology for producing twin-rib brackets. This method is unique on a global scale, and its basic assumptions have been granted patent protection. Also, the originality of the study stems from the fact that brackets are made from magnesium alloys, as these light metals are considered the future of structural materials used in the aircraft industry. Given the above, the research on developing the technology for producing parts made from these alloys using a three-slide press is justified.

The purpose of this paper is to analyze machinability of CFRP, GFRP, GLARE-type composites in drilling process taking into account their features and properties (the geometric characteristics, the volume fraction and the mechanical properties of the individual components of the composite). Drilling in non-plan surfaces and slope drilling.

The tests were carried out in two stages: perpendicular drilling of materials such as GLARE with special drill bits, and drilling of composite structures with non-planar surfaces made of unidirectional carbon fiber prepregs, using the modified special drill. Measurement of cutting forces and torque, stress distribution (photoelastic method) and a visual assessment of defects occurring during drilling allowed to determine the relationship between the type and geometry of the composite drill.

Identified great effect of kind of composite on the machinability of these materials has substantiated modification of the standard geometry of drills and matching this geometry to specific properties of the various type of composites.

Drilling of assembly holes for aerospace parts.

New type of drill geometry for different type of composite.