Aircraft Construction Research Articles

Fretting wear behaviour in 6061-T6 aluminium alloy

Abstract In this study, fretting wear in riveted lap joints of aluminium alloy plates was investigated. For the fretting test, 6061-T6 aluminium alloy plates, which are widely used in aircraft construction, and blind rivets were used. Experiments were carried out using a computer controlled Instron testing machine. Fretting surface roughness, microhardness was investigated by metallographic techniques and scanning electron microscopy. Tensile load cycles in the riveted lap joint were found to cause damage to all surfaces. Two contact surfaces where friction occurs were investigated. The contact surface of the lower plate with the upper plate, and the contact surface of the lower plate with the rivet head. As load and cycles increased, fretting scars and surface roughness increased. Consequently, it has been determined that fretting damages occur between the contact surface of the plates and between the plate and the rivet contact surface.

Evolution of Airframe Materials for Russian Fighters

Fighter aircraft make extensive use of materials such as Steels, Aluminum alloys, Magnesium alloys, Titanium alloys and composites for construction of airframe. It has been seen that many of the airframe materials used in Russian fighters are common. But attempt has been made to introduce progressively superior quality alloy grades in the later version of aircraft. A comprehensive study (1) is thus made to identify the important structural member of the airframe and its materials in different generations of the Russian fighters to highlight the ways lighter and superior alloys replaced steels. This paper describes the application of various aerospace materials used from the evolution of old generation Russian combat fighters to latest Russian fighters. Effort have been made to analyse and explain the change of some of the grades within the domain of these Russian fighters and use of superior structural materials (western and Russian origin) to old age aircraft to enhance the performance. It also discusses the percentage weight change of various types of materials used in the construction of Russian fighter aircrafts under operation in India. Main objective of this study which is discussed here, to keep aware the operators as well as manufacturer’s of Russian aircrafts within India to exchange these Russian materials during rationalization, substitution, indigenization and at a times of short supply or non-availability of these grades based on their merits.

An ultrasonic scanning system for the inspection of composite stiffened panels from elastic constant identification via inversion of guided waves

This paper describes an ultrasonic scanning system for the inspection of stiffened composite panels used in modern aircraft construction based on elastic constant identification. Conventional ultrasonic scanning systems track individual features of the propagating waves (e.g. amplitude, arrival time, etc.) to detect damage by tracking the associated wave scattering. An ability to map the elastic constants of the composite part can greatly enhance the sensitivity of the scan to structural damage that can be detected and quantified by a corresponding reduction in the stiffness components. Elastic constants can be also correlated to residual strength. The proposed scanning system utilizes a “single-input-dual-output“ (SIDO) scheme whereby ultrasonic guided waves are excited by an impact and detected by two air-coupled ultrasonic sensors. The phase velocity dispersion curves of the waves are experimentally measured under a single excitation at each scanning line using a phase-spectrum technique. These curves are then inverted using a Semi-Analytical Finite Element (SAFE) method as the wave propagation forward model and Simulated Annealing as the optimization routine. This approach yields estimates of several elastic effective constants of the composite panel at each scanning line. These constants are then related to impact damage in stiffened stringer-skin composite panels.

Influence of aging heat treatment at 180 °C on cavitation erosion for aluminum alloy type 5083 in cold rolled state

Aluminum-based alloys have wide applicability in the construction of aircraft, vehicles, and ships. Some of their components, during operation, such as the radiators and the rotors of the cooling pumps in the vehicles, and the propellers of fishing and pleasure boats are affected by the abrasive, chemical and cavitational corrosive action of the water. At certain hydrodynamic flow regimes, the most dangerous becomes the corrosion through cavitation. Operation in such regimes inevitably leads to damaging the structure, due to cyclic stresses of the micro-jets and shock waves generated by the implosion of cavitation bubbles. Although the chemical constitution and alloying with other chemical elements increase the mechanical properties, the service life is still limited when operating in high-intensity cavitation flows. Therefore, researchers are looking for solutions to improve this resistance through various treatments, such as bulk heat. Research heading the same direction, but, made on 5083 alloy, is presented in this paper. The results highlight the behavior of a modified structure compared to the semi-fabricated state (obtained by rolling), through three durations regimes (one hours, 12 hours and 24 hours) of aging heat treatment to 180 °C temperature, after hardening treatment at 450 °C. The cavitation tests were performed in the Laboratory of the Polytechnic University of Timisoara, on the standard vibrating device with piezoceramic crystals. The results were expressed by curves and parameters specific to the evaluation of cavitation resistance, and by macro and microscopic images, showing the unique aspects of the connection between the structure and the mechanical properties obtained through heat treatment regimes. Thus, comparison of the results, including with the delivery state (laminated product), shows that the highest resistance is provided by the treatment at 24 hours. At the same time, the erosion, of pitting and caverns type, and differs from one structure to another.

Free vibration analysis of the sandwich structured composite annular plates: Numerical and experimental investigation

Sandwich structures are interesting structural elements due to their high stiffness-to-weight ratio, high fatigue resistance, and excellent vibration characteristics. The aerospace industry relies heavily on these types of structures considering the different optimized materials and shapes available for sandwich construction. In the present study, vibration aspects of annular sandwich structures with composite laminates and a 3D printed honeycomb core are investigated in both the numerical and experimental methods. Amongst the various shapes of sandwich structures, annular sector plates are predominantly used in the construction of modern bridges, aircrafts, and automobile parts. Furthermore, the investigation of annular sandwich plates featuring GFRP facesheet and 3D printed PLA cores are studied in a very limited extent. In order to obtain the sector plates experimentally, Glass Fiber Reinforced Polymer (GFRP) laminates are fabricated by hand layup techniques, and the 3D printing Poly-lactic Acid (PLA) honeycomb core is manufactured using Fused Deposition Modelling (FDM). The material properties of honeycomb core and composite skins are estimated with the help of Gibson formulation and rule of mixture, respectively. Based on available literature, the analysis approach is validated through numerical analysis using ANSYS Finite Element (FE) software. Also, the frequency responses of annular sandwich plate were measured in both experimental and numerical analysis and the results showed good agreement. However, in order to describe the effectiveness of annular composite sandwich plates, parametric studies are carried out in terms of natural frequencies and mode shapes with different configurations of core geometry, ply orientation, boundary constraints, and inner to outer radius ratio. The research outcome highlights that the optimum angle ply orientation, core height of 12.5 mm with clamped–clamped condition and inner to outer radius of 0.75 mm yields better structural stiffness.

CERTIFICATE PROGRAMS OF THE AVIATION FIELD FROM THE PROGRESSTECH-UKRAINE COMPANY

The paper considers the implementation of certificate programs at the bachelor's level of higher education for students of five technical faculties of The National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute» as an element of dual education. Certificate programs include such courses as: passenger aircraft design, passenger aircraft systems, «heavy» CAD system CATIA, aircraft construction technologies, the general structure of aircraft and their units, features of the science-intensive products construction of machine-building production and conducting pre-diploma practice. The development of these courses and the conduct of classes are carried out exclusively by Progresstech-Ukraine engineers. Training takes place on the basis of the Learning Management System (LMS). Currently, 103 students are studying according certificate programs.

The strength calculation of the transport aircraft control system element by the finite element method

The work is devoted to determining the stress-strain state of the element of the control system of the transport aircraft, which serves to transmit motion and is an element of the mechanism for deflecting the rudder and removing the load from the control wiring. If this element is destroyed, the control system will not function, as a result of which some elements of the electronic installation of the aircraft will be disabled. Analytical methods are not always effective when studying the stress state of complex parts and mechanisms of aircraft construction, although they are also used. To determine the stress-strain state in the work, a numerical method was used - the finite element method, which models the stress-strain state of mechanical systems with great accuracy, taking into account the boundary conditions and the given load. A four-node tetrahedral element was chosen as a finite element. Based on the analysis of the stress-strain state, dangerous places in the structure were identified, where there is a possibility of a crack appearing and, as a consequence, destruction.

Influence of exposure in a corrosive environment on ultimate stress of heat-treated welded joints of Al–Mg–Si–Сu alloy

Abstract The priority task of modern aircraft construction is to ensure the reliability of the operation of structures, which depends both on the quality of execution of technological processes during manufacturing and on the corrosion-mechanical durability of welded joints. This work aims to study the influence of contact duration with a corrosive environment on the mechanical strength of the base metal and welded joints of the Al–Mg–Si–Cu alloy, heat-treated in different modes (artificial aging, quenching followed by artificial aging). Corrosion-mechanical tests were carried out under constant axial tensile stress in 3 % NaCl solution for 14 days, followed by determination of the corrosion rate, ultimate strength, and fractographic analysis of the fracture surface. The results showed that the corrosion resistance of the joints is almost equal to the corrosion resistance of the base metal. It was experimentally confirmed that the ultimate strength of the base metal and welded joints decreased after corrosion exposure in a 3 % NaCl solution. This is caused by the embrittlement of the structure and the formation of corrosion defects in the near-surface zone during contact with a corrosive environment, which led to a change like a fracture from ductile to ductile with brittleness.

Investigation of microstructure of fretting wear behavior in 6061-T6 aluminum alloy

PurposeThe purpose of this study is to investigate the microstructure of fretting wear behavior in 6061-T6 aluminum alloy. The fretting wear of blind riveted lap joints of 6061-T6 aluminum alloy plates, which are widely used in aircraft construction, was investigated. Fretting damages were investigated between the contact surface of the plates and between the plate and the rivet contact surface.Design/methodology/approachExperiments were carried out using a computer controlled Instron testing machine with 200 kN static and 100 kN dynamic load capacity. Max package computer program was used for the control of the experiments. Fretting scars, width of wear scars, microstructure was investigated by metallographic techniques and scanning electron microscopy.FindingsIt was found that fretting damages were occurred between the plates contacting surface and between the plate and rivet contact surface. As load and cycles increased, fretting scars increased. Fretting wear initially begins with metal-to-metal contact. Then, the formed metallic wear particles are hardened by oxidation. These hard particles spread between surfaces, causing three-body fretting wear. Fretting wear surface width increases with increasing load and number of cycles.Originality/valueThe useful life of many tribological joints is limited by wear or deterioration of the fretting components due to fretting by oscillating relative displacements of the friction surfaces. Such displacements are caused by vibrations, reciprocating motion, periodic bending or twisting of the mating component, etc. Fretting also tangibly reduces the surface layer quality and produces increased surface roughness, micropits, subsurface microphone.

Advancing Power Supply Devices for Electric Aircraft

The pollution caused by the construction of more aircraft that run on fuel will become more severe as more fuel-energy aircraft are built. As a result of the numerous environmental crises currently confronting the world, electric jumbo jets need to replace those that run on fuel. Note that the most interesting issue would be the airplane's power supplies. Research is conducted on the physical principles underpinning solar panels and power beaming. Batteries are an essential component of electric aircraft. The materials used to construct airplane batteries are among the most crucial aspects of battery design, and lithium-ion batteries are among the top options available. The capacity of the batteries will not decrease over time, and they will not catch fire or put passengers at risk. In order to maintain charging, a one-of-a-kind combination of sulfur and selenium is utilized. It has been discovered that solid sulfur selenium batteries have a good touch, do not ignite, are thinner (even thinner than lithium-ion batteries), and have a higher capacity for storing energy than lithium-ion batteries.

Development of Heat-Resistant Composite Foam Material

The paper is devoted to the research results dealing with the development of heat-resistant composite cellularmaterial, where polymer matrix is based on10% polycarbosilanesolution in xylene, hollow microspheres and fibrous mineral material are used as fillers. In this study, the used hollow microspheres are corundum and aluminosilicate microspheres, and fibrous filler is quartz fiber. According to the experiments, the best results refer to thecomposite foam samples, containing hollow corundum microspheres as filler. The developed composite foam is characterized with low thermal conductivity and density, good physical and mechanical properties,when polymer binder content was 20-70% wt., corundum hollow microspheres - 20-60% wt., and quartz fiber material - 10-50% wt. Thus, the developed composite foam might be recommended for the applicationin high-tech industries, including heat and power engineering, nuclear power and aircraft construction as high-temperature thermal insulation material.

Aviation and carbon emissions: Evidence from airport operations

Carbon emissions have become a significant concern for the development of the aviation industry. Current studies provide valuable insights into aircraft and airport construction's effect on carbon emissions at a micro level, while the impact of airport operations on cities' carbon emissions at a macro level remains under-investigated. This study investigates whether and how airport operation would affect cities' carbon emissions. This study draws a causality relying on a quasi-natural experiment based on airport operation shock events that increased certain cities' transportation options and changed cities' economic activities and carbon emissions. A total of 4938 datasets among 280 China's prefecture-level cities during the period 1999–2017 are analysed via the Difference-in-Differences model. Our estimation results show that airport operation significantly increases cities' carbon emissions, with a 4.3% increase in carbon emissions in cities that opened new airports compared to those cities without new airport operations. The mediation effect indicates that the substitution impact of transport increases cities' carbon emissions by 0.3%. Furthermore, increasing the science and technology expenditure ratio can offset the impact of airport operations on cities' carbon emissions. Our study provides implications for policymakers and stakeholders concerning mitigating carbon emissions to promote the green aviation industry and optimise airport construction and operation.

Using the Pulsed Eddy Current Techniques for Monitoring the Aircraft Structure Condition

Abstract It is known that during operation, the aircraft construction materials are exposed to significant mechanical loads and changes in temperature for a very short period of time. All this leads to various defects and damages in the aircraft assemblies and units that need to be inspected for the safe operation of the aircraft, their assemblies, and units. In some cases, the implementation of inspection or diagnostic is accompanied by the emergence of technical difficulties caused by the large size of the aircraft assemblies or units and limited access to their local places. Under such conditions, ensuring the possibility of diagnosis in hard-to-reach places of the object becomes especially important. The problem can be solved by applying wireless technologies. It allows spatial separation of the probes and the signal processing units, which simplifies the scanning of the surfaces of the large assemblies and units in hard-to-reach places. In this article, the description of the developed wireless system of eddy current inspection for aircraft structural materials is given. Experimental results of object scanning are given in the form of a distribution of the values of probe signal informative parameters (amplitude, frequency and decrement) along the object coordinates.

ВПЛИВ МАТЕРІАЛУ СМУГИ ТА СХЕМИ УКЛАДАННЯ ШАРІВ КОМПОЗИЦІЙНОГО МАТЕРІАЛУ НА КОЕФІЦІЄНТ КОНЦЕНТРАЦІЇ НАПРУЖЕНЬ У СМУЗІ З ОТВОРОМ ПРИ ЇЇ РОЗТЯГУВАННІ

At present, there is a tendency to increase percentage of the use of composite materials in the structures of modern aerospace technology. Experience in the operation of critical structures of aerospace engineering made of polymer composite materials has shown that their application instead of structures made of metal alloys provides a reduction in the mass of the structure by up to 30–50%, an increase in the service life by 2–5 times, a decrease in the labor intensity of manufacturing by 20–40% and material consumption - up to 50 %. Application of composite materials in the construction of aircrafts requires the development and application of methods for analysis their static and fatigue strength. The influence of the plate material and composite material plies stack-up sequence on the distribution of normal stresses and the stress concentration factor in the plate with a hole at B/d=6 under uniaxial tension has been studied. It has been shown by calculation that in the case of the orientation of the plies in the same direction with an angle q=0°, the maximum normal stress sх is 1.5 times greater than the corresponding stress value in a plate with a hole made of D16T aluminum alloy. Application of the plies stack-up sequence q [45°/-45°] enables to reduce the level of maximum stresses sх to the level of stresses in the plate with a hole made of D16T alloy. In this case, the area of maximum stresses is shifted from the vertical diametral point along the arc of the hole by an angle of 22.5°. For a woven composite, the level of maximum normal stresses sх is lower than the corresponding stress level for a fiber composite. When using plies stack-up sequence q [45°/-45°], the level of maximum normal stresses sх is lower than the level of the corresponding stresses in the plate with a hole made of D16T alloy. It has been found that, in contrast to the D16T alloy plate, in a plate with a hole at B/d=6, the stress concentration factor could be less or greater than 3, which is explained by the influence of plies stack-up sequence on the stress concentration factor. For a woven composite, when using plies stack-up sequence q [45°/-45°], we obtained the value of the stress concentration coefficient equal to 2.28.

Static strength prediction of curved composite joints under internal pressure

ABSTRACT Nowadays, adhesive joints are largely applied in the automotive, aircraft and aerospace, civil, and naval industries. Although several applications involve flat (plane) adherends, curved joints play an important role in many engineering applications like civil and aircraft construction. This work aims to investigate three structural adhesives, ranging from brittle to ductile, applied in curved joggle-lap joints between carbon fibre reinforced polymer adherends and subjected to internal pressure, to validate a robust design procedure and provide project guidelines for this complex structural, geometrical, and loading system, which constitute the main novelty of the proposed work. A numerical cohesive zone model parametric analysis was undertaken by varying the overlap length, thickness of the adherends, and adherends’ curvature, including the evaluation of peel and shear stresses in the adhesive, failure mode comparison, maximum load, and energy dissipated after failure. Validation of the cohesive zone model technique was initially performed using flat single-lap joint under tensile loads. A significant effect of the overlap length and thickness of the adherends on the maximum load was found, while the adherends’ curvature effect on the maximum load was negligible. Ductile adhesives, although less strong, generally performed better in terms of maximum load and dissipated energy.

DEVELOPED MILITARY ECONOMY AS A COMPONENT OF UKRAINE’S NATIONAL ECONOMIC STRATEGY

Purpose. The principles, strategic goals and directions of the development of the military economy in the structure of the national economy and its influence on the formation of the military-economic policy of the state to ensure its modern military-economic security have been determined. Design/methodology/approach. In the article, the author used the following methods: analysis and synthesis – to analyze modern trends and generalize their impact on the formation and development of the military economy; systemic method – to reveal the essence of the military economy through the prism of the formation of military-economic potential and national security; statistical – for ranking the most powerful armies in the world and outlining the military and economic potential of Ukraine; comparison – to determine the volume and share of military defense expenditures of a number of states and the volume of sales of weapons and military services in the world in a geographical dimension; strategizing – for the formation of strategic goals of the policy of the national economy of Ukraine; generalization – when formulating conclusions and recommendations. Based on a review of the literature, the author determined the goals of analyzing the indicators of military and defense spending among a number of countries in the world, the dynamics of sales of weapons and military services, and substantiated the main defense trends of governments and a number of enterprises of many states. The strategic objectives of the policy of the national economy of Ukraine considered by the author made it possible to form conclusions, the reliability of which is based on the interpretation of the indicators given in the analytical part. Findings. The a proven hypothesis that the level of spending on national defense makes it possible to guarantee a high level of military-economic security, which is the fundamental function of the state. This condition in the military-economic potential can be achieved only thanks to the formation of the military-economic concept of the state, which is based on its historical experience, on the study of similar concepts and practices of states with different economic models, which reflect scientific and technical achievements. Also, the requirement of the present and the future is the need to develop special components in the structure of the military economy of Ukraine: nuclear military industry; rocket engineering; aircraft construction; tank construction; shipbuilding; production of artillery systems, rocket launchers and robotic systems, hypersonic weapons, unmanned aerial vehicles, anti-ship missiles and medium and long-range ballistic missiles; production of small arms and ammunition; production of radar surveillance systems, anti-satellite technologies and weapons with artificial intelligence, etc. This will require a constant increase in the military budget and spending on scientific research, as a certain annual share of Ukraine’s GDP Practical implications. The results of this study are of interest to state authorities, business entities in the field of the defense-industrial complex, who seek to expand and modernize the sphere of the military economy, increase the innovative and technological level of military equipment, weapons and dual-purpose products in accordance with the conditions of competitive markets and ensure employment growth at military industry enterprises. In addition, the results can help scientists of higher education institutions to improve tools for expansion of innovative knowledge and build scientific potential in the field of military technologies. Originality/value. This study emphasizes the peculiarities of the formation of the military economy sector in the structure of the national economy and its impact on the investment and innovation activity of industrial enterprises that produce dual-use products. The outline of the defense trends of governments and a number of enterprises of many states made it possible to form the strategic goals of the policy of the national economy of Ukraine in the defense sphere. Provide recommendations to the authorities regarding the development of the military industry and the adoption of a number of institutional decisions at the state level.

Fabrication and characterization of woven and comingled nonwoven sheet polypropylene hybrid composite by recycling and alkali-treated jute waste fibers

Natural fiber reinforced hybrid composite materials, with their enhanced characteristics, represent the future of our advanced material search. Natural fibers are the substitute for synthetics because their less manufacturing cost, bio-degradable, easy availability, durability, resistance to environmental degradation, etc., makes them popular nowadays. This paper presents how jute fibers are recycled from various jute waste sources. After recycling, jute fibers are used to fabricate the hybrid composites. Two forms of recycled jute sheets are used to fabricate the composites that is, woven sheets and nonwoven comingled (jute and polypropylene) sheets. The NaOH treatment was performed on recycled jute sheets with different concentrations (0%, 2%, 4%, 6%, and 8%). The hybrid composites are made using three distinct fiber-polypropylene weight fraction ratios (50/50, 40/60, and 30/70), as well as five different stacking sequences. Mechanical parameters such as tensile strength, elongation (%), flexural strength, impact strength, and water absorption were evaluated. Among the five fabricated combinations, it is found that the combination of (40/60), (JJJ), with 2% NaOH treated fibers composite gives the maximum tensile and flexural strength, and the combination of (30/70) (CCC) with 2% NaOH treated fiber composites exhibits the maximum Impact strength. The combination of (50/50), and (CCC) with 2% NaOH treated fiber composite gives the maximum Elongation %, and the combination of (50/50), (JJJ), and 0% NaOH treatment yields the maximum water absorption. A relationship between fabric loading, tensile modulus, and flexural modulus and other relationship between chemical treatment and water absorption% has been established for JJJ laminated sheet which shows almost best properties among them. These assessments make them most valuable for a variety of sectors, including car, aircraft, marine, and building construction.

Influence of hybrid nanoparticles on the wear behavior of aluminum alloy composites for aerospace applications

PurposeEngineers and scientists are searching for novel materials with high performance on all aspect points of view for the applications including marine, aero and automobile fields. AA8090 aluminum alloy is one of the materials used in aero industries for aircraft construction because of its weight reduction ability. However, the AA8090 alloy has a drawback such as low wear resistance that affects the life time of material; hence, it should be addressed. The purpose of this investigation is to improve the wear resistance of AA8090 alloy.Design/methodology/approachIn this investigation, AA8090 aluminum alloy metal matrix composite was fabricated using different types of carbide nanoparticles such as vanadium carbide (VC), Cr3C2 and Mo2C by stir casting method and tribological and mechanical behaviors were studied.FindingsMechanical studies showed that the S1 sample displayed the maximum hardness of 142 HV and maximum tensile strength of 857 MPa because of the inclusion of hard VC particles. Tribological studies revealed that S1 sample showed high performance. A least wear rate of 0.003915 × 10–3 mm3/m was noted for S1 sample, which is 71% lower than the wear rate of S0 sample. Further, a least mass loss and lower coefficient of friction of 0.00152 g and 0.2, respectively, were observed for S1 sample because of its high hardness and high wear resistance because of the stuffing of high-hardness VC particles. Hence, it is concluded from this study that S1 sample, i.e. AA8090/VC, could be a better candidate for aerospace applications as it showed good tribological and mechanical properties.Originality/valueTo the best of the authors’ knowledge, this work is original and novel in the field of metal matrix composite which deals with the effect of hybridization on the wear performance of the aluminum alloy composites.

Registration of the Growth of Manufacturing Defects by the Monitoring System During the Operation of the Structure

Structural composite materials are currently increasingly used in various fields of modern technology. The potential capabilities of composites exceed those of traditional materials due to particular mechanical characteristics and fundamentally new qualities arising from the simultaneous creation of material and structure. This paper describes the experience of using fiber-optic distributed and piezoelectric sensors to monitor the state of samples of materials used in the construction of aircraft. Characteristic forms of responses from fiber-optic and piezoelectric sensors are presented, which make it possible to determine the growth of delamination that occurs in polymer composite materials under various impacts.

The influence of adhesive material properties on the impact strength of adhesive block connections

Adhesive connections are becoming increasingly popular in the construction of aircraft and other means of transport. Today, bonding is mainly used in the construction of helicopter fuselages, wings or lifting rotors. The increased popularity of bonding is forcing designers to seek new and improve research methods as well as enhancing the existing test methods which specify the static, fatigue or impact strength of joints. A variety of tests are used to determine the strength of structures, although new ones are constantly being sought so as to be applied more quickly and without specialised equipment. Current testing standards are also being modified in order to speed up and simplify the testing process, resulting in safer structures that use adhesive bonds. The aim of the research presented in this paper was to test whether there is a relationship between the mechanical properties of adhesive materials and the impact strength of adhesive block joints with a cylindrical top element. Steels S235, Raex 400 and PA6 aluminium alloy were used for the manufacture of the samples. From each material, 10 samples were prepared with upper elements of different diameters, namely: 17.8 mm, 12.6 mm and 8.9 mm. A pendulum hammer was used to determine the strength of the adhesive bond against dynamic load application. For the sake of the research, the authors used a modified PN-EN ISO 9653 with a mounted hammer equal to the maximum energy of 15 J. Lower failure energy was characteristic of samples made from material with a lower value of Young's modulus (dural) and from steel with a lower yield strength. The connection failure energy grew with increasing the joint area, which was approximately parabolic.