Grzegorz Lesiuk

• PhD DSc Eng. Assoc. Professor
• Professor (Associate) at Wrocław University of Science and Technology

In this paper, the fracture surface topography of additively manufactured Haynes 282 alloy subjected to tensile and high-cycle fatigue loading was investigated. Haynes 282 alloy bars were printed in three different directions relative to the base plate (0°, 45°, and 90°) via Direct Metal Laser Sintering (DMLS) under an argon protective atmosphere....

Dilatometric phenomena, mechanical and antifriction properties of a new high-temperature composite based on powder nickel alloy EP975 with additives (4.0− 8.0)% CaF 2 solid lubricant have been investigated. New composite has been manufactured using hot isostatic pressing (HIP) technology with subsequent hardening heat treatment. Antifriction proper...

The principles of the mechanisms for fatigue crack propagation in metals have been established several decades ago. By definition, fatigue might be summarized as a damage process imparted to a material under the action of cyclic loads. The relation between fatigue crack growth rates (FCGRs) and formation of striation marks has been a controversial...

Leaf springs are critical components for the railway vehicle safety in which they are installed. Although these components are produced in high-strength alloyed steel and designed to operate under cyclic loading conditions in the high-cyclic fatigue region, their failure is still possible, which can lead to economic and human catastrophes. The aim...

Leaf springs are critical components for the railway vehicle safety in which they are installed. Although these components are produced in high-strength alloyed steel and designed to operate under cyclic loading conditions in the high-cyclic fatigue region, their failure is still possible to occur and hence lead to economic and human catastrophes....

Dear Colleagues, The accumulating damage and growth of cracks under the influence of cyclic loads is a common phenomenon occurring in metals, alloys, welded elements, and others. Most damage to machine components occurs during fatigue work. Experimental tests and simulations are required to determine the impact of various factors on fatigue and cr...

This article presents the results of numerical simulations of a structural system consisting of steel perforated thin-walled beams and a steel grating. The simulations were conducted using the finite element method. The analysis took into account physical and geometric nonlinearity as well as the contact between the steel grating and the beams. The...

This paper presents a method for estimating the fatigue life of polyurethane elastomeric components. A rubber replacement-polyurethane of hardness 80ShA commonly used in vibration damping systems, for example, in motor vehicle suspensions, was used for the study. A metal-rubber bushing component was selected for analysis, and numerical analysis was...

An experimental and numerical investigation of the cylindrical carbon fiber reinforced polymer (CFRP) structures under various loads including tension/torsion loading conditions has been conducted. Various boundary conditions and parameters were taken into account to check the impact of the shear component to obtain the result. The nonlinear shear...

In this paper, preliminary studies on the failure analysis of hybrid composite materials utilizing acoustic emission and machine learning are presented. The main purpose of this study was to analyze the possibilities of using machine learning techniques as a way to better cluster the data obtained from acoustic emission. In this paper, we focus on...

In this paper, the application of an Autocorrelation Function for the characterisation of surface topography was validated. The roughness evaluation of turned composite surfaces was supported by sophisticated studies of the Autocorrelation Function properties, considering especially the shape of the function. Details were measured with the optical...

Three different types (with glass, basalt and hybrid fibres) of composite rebars manufactured using the pultrusion process were loaded in four-point bending tests. All tests were carried out with acoustic emission sensors to better understand the mechanisms of damage. The data obtained were investigated using standard parameter analysis and also us...

Metals have played an immensely significant role throughout the history of humanity, to the extent that different periods of human development have been marked by the dominance of specific materials, such as the Bronze Age and the Iron Age [...]

This paper examined the cyclic deformation behaviour of multiphase low-carbon steel that was subjected to austempering heat treatments at four temperatures (190 °C, 230 °C, 275 °C, and 315 °C) below the martensite start temperature (Ms = 353 °C). The tests were conducted at room temperature, under fully reversed strain-controlled conditions, with s...

One of the most important aspects of engineering assessment of the technical condition of structures and materials is the ability to assess the fatigue behavior of materials and structures [...]

In this paper, pultruded GFRP bars are investigated to determine their fracture properties. The double cantilever beam test (DCB) is used to assess fracture behavior under mode I loading conditions. However, due to the presence of the R-curve effect (variable fracture energy dependent on the length of the crack), it is necessary to introduce a nons...

Additive manufacturing technologies have numerous advantages over conventional technologies; nevertheless, their production process can lead to high residual stresses and distortions in the produced parts. The use of numerical simulation models is presented as a solution to predict the deformations and residual stresses resulting from the printing...

Polyurethane (PU) has been used in a variety of industries during the past few years due to its exceptional qualities, including strong mechanical strength, good abrasion resistance, toughness, low-temperature flexibility, etc. More specifically, PU is easily “tailored” to satisfy particular requirements. There is a lot of potential for its use in...

Recently, a trend in fatigue testing related to increasing excitation frequencies during experiments has been observed. This tendency is a product of both necessity and available technological capabilities. Regarding the last, advances in control and excitation systems made it possible to perform tests at impressive frequencies, beyond the tenths o...

Stainless steels, especially AISI 304, are increasingly used civil engineering materials in the last years because they have excellent properties. They are used for many civil engineering structures e.g. chemical, energy, bridges etc. The presented study brings results of the observation of micro-structure and results on basic mechanical properties...

Testing beyond 10 millions of cycles in a conventional fatigue machine is a very time consuming task, so the fatigue limit has been settled around this number of cycles. However, during the service life, several engineering components experience a number of cycles larger than 10 million cycles. For that reason, the region of very high cycle fatigue...

In the paper, a design of experiment (DOE) in terms of the Taguchi method was used for the optimization of the manufacturing process. This approach makes it possible to do fewer experiments while still getting the desired outcomes. This research programme will use this tool to optimize the resin casting process by monitoring manufacturing parameter...

The low-carbon bainitic steel after a continuous cooling process was subjected to fracture toughness investigations using the J-integral approach. The research was focused on the determination of microstructural factors influencing the fracture processes considering the crystallographic units, as well as dimensions and morphology of phases. It was...

Fire resistance is a major issue concerning composite materials for safe operation in many industrial sectors. The design process needs to meet safety requirements for buildings and vehicles, where the use of composites has increased. There are several solutions to increasing the flame resistance of polymeric materials, based on either chemical mod...

This paper presents the results of a study of polyurethane rigid (PUR) elastomers in terms of the constitutive law identification, and analyses the effect of polyurethane elastomers’ hardness on fatigue properties. The research objects were PUR materials based on 4,4′-diphenylmethane diisocyanate (MDI) with the hardness of 80 ShA and 90 ShA, typica...

Fibre metal laminates (FML) are layered materials consisting of both metal and reinforced composite layers. Due to numerous possibilities of configuration, constituent materials, etc., designing and testing such materials can be time- and cost-consuming. In addition to that, some parameters cannot be obtained directly from the experiment campaign....

Engineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural...

Numerous studies were conducted on the tension-compression fatigue behavior of Inconel 718 (IN718) fabricated with laser powder bed fusion (LPBF). Contrary, only a few fatigue crack growth rate (FCGR) studies are available in the literature. Considering the above, LPBF manufactured IN718 is heat treated in variants including (H) and excluding (A) h...

Fatigue crack growth modelling for S355 structural steel considering plasticity-induced crack-closure by means of UniGrow model, Abstract: The UniGrow model is an analytical procedure to assess the fatigue crack growth based on elastic-plastic crack tip stresses and strains. The assumption is that fatigue crack growth (FCG) can be considered as a p...

In this research work, the modelling of the fatigue crack growth behaviour of the 6061-T651 aluminium alloy through the Huffman fatigue crack growth approach, based on the strain energy density from dislocations and considering the residual stress effects was suggested. The Huffman fatigue crack growth model is based on the cyclic stress–strain beh...

The study presents the results of the research on the rate of fatigue crack growth subjected to bending in the ferritic-pearlitic structure. The studies were carried out at a constant amplitude of the moment and at various values of the load ratios R and at the operating frequency of the machine of 28.4 Hz. Flat specimens made of S355 steel and wit...

Fiber metal laminates (FML) are hybrid materials consisting of metal and composite layers. They have great mechanical and fatigue properties. However, interface between metal and composite layers can be critical for their final properties. In this paper, process of determination of some fracture parameters of this interface in unusual FML material...

The paper contains the results of an experimental investigation of fatigue crack development under mixed-mode I + II and I + III in heat-treated 42CrMo4 steel. Tests were performed on heat-treated compact tension shear specimens and rectangular cross-section specimens for mixed-mode I + III. Mixed-mode I + II tests were conducted for 30 and 60° loa...

In Europe, several bridges, as Luiz I bridge in Porto, are at the end of their service life, which is pretended to extend due to cultural value of these structures. The application of carbon reinforced polymers (CFRP) in certain regions of the structures under maintenance is a widely used methodology of strengthening. Thus, this work aims to charac...

This paper presents the numerical simulation of the GFRP rebars subjected to the bending loading. Additionally, the comparison of the mechanical properties of CFRP/GFRP laminates with different fiber volumes is given according to the widely used hypotheses available in the literature. The most suitable hypotheses are the Abolish regarding Kirchhoff...

Cast iron probably represents one of the most widely utilized constructive materials in our modern industrial world. This is due not only to the excellent mechanical and tribological properties, but also to a certain flexibility of the same. In fact, it can be produced in various types of metal alloy, which differ significantly in properties: from...

In the paper, the problem of long-term operated materials from nineteenth-century steel was discussed. The detailed analysis was focused on materials aspect and strength degradation based on the experimental results from rivets and metal plate from materials extracted from Sand Bridge (1861) located in Wrocław, Poland. As it is reported, the most s...

This paper presents the experimental results of composite rebars based on GFRP and CFRP manufactured by a pultrusion system. The off-plane compression strength of rods was determined. This compression test reflects the weakest nature of the composite materials based on the interlaminar compressive strength. The proposed methodology allows us to inv...

Stainless steels are widely used engineering materials providing excellent properties. They have applications in many industries (chemical, energy, food production and civil engineering). The presented study aims to evaluate the effect of specimen thickness on fatigue crack growth behavior in stainless steels AISI 304L. Two grades of stainless stee...

An experimental and analytical approach to the relaxation problem of wood-based materials—OSB (Oriented Strand Boards—pressed wood-based composite panels) beams, including beams with CFRP (Carbon fiber reinforced polymer) tape composite reinforcement, is presented. It is a relevant engineering and scientific problem due to the fact that wood and wo...

This work aims to evaluate the degradation mechanisms of selected composite bars subjected to exposure to various chemical environments. Sets of three different groups of bars, such as glass fiber reinforced epoxy pultruded at Wroclaw University of Science and Technology (WUST), commercial glass fiber reinforced epoxy overwrapped with carbon fiber,...

The paper brings results of high‐cycle fatigue and very‐high‐cycle fatigue tests of the steel S355 tested during low‐ and high‐frequency loading. Two grades of structural steel (S355J0 and S355J2) were tested to gain fatigue properties that serve as inputs to reliable finite element calculations of cyclically loaded structures. Experimental measure...

The problem with composite rebars in the civil engineering industry is often described as the material’s brittleness while overloaded. To overcome this drawback, researchers pay attention to the pseudo-ductility effect. The paper presents four-point bending tests of pure unidirectional (UD) rods with additional composite layers obtained by filament...

This work presents global and local fatigue approaches for snug-tight (common in rack structures) and preloaded bolted joints using thin hot-dip galvanized steel plates, where the zinc coating results in a low friction coefficient. Moreover, S-N data supporting the current revision of Eurocode 3 (EN 1993-1-9) is generated by considering remote and...

Fatigue is one of the main causes of failures as well as mechanical fractures in structural details made of aluminium alloys under cyclic loading, where the materials (during the crack growth process) are subject to the stress R-ratio effects and crack closure phenomenon. In this research work, a comparison of the effect of various crack closure/op...

Fiber metal laminates (FML) are hybrid materials consisting of metal and composite layers. They have great mechanical and fatigue properties. However, interface between metal and composite layers can be critical for their final properties. In this paper, process of determination of some fracture parameters of this interface in unusual FML material...

The fatigue crack initiation and propagation phases have been widely studied by the scientific community. There are several models to describe low-cycle fatigue behaviour based on strain damage criteria, but the most widely used is the Coffin-Manson-Morrow relationship, normally used for the fatigue crack initiation modelling. In addition, strain-l...

This paper presents experimental research aimed at addressing the fatigue behaviour of thin-walled cold roll-formed steel sections, very commonly used in rack structures. This research is performed under the FASTCOLD-RFCS project, which aims to fill an existing gap on fatigue design rules. A new design S-N curve is derived from an innovative testin...

The paper presents a comparison of the results of the fatigue crack growth rate for raw rail steel, steel reinforced with composite material—CFRP—and also in the case of counteracting crack growth using the stop-hole technique, as well as with an application of an “anti-crack growth fluid”. All specimens were tested using constant load amplitude me...

Although several old riveted bridges served more than 100-150 years in the world, some of them are still in the application, generally limited by the economic budget or cultural relic protection reason. Hence, the status of those bridges needed to be evaluated to support the bridge management and rehabilitation, especially with the increasing traff...

In recent years, the possibility of using bainitic steels in railways has aroused considerable interest due to the promising mechanical properties and performance in service. Concerning fatigue performance, the published research does not unequivocally indicate the bainitic rails' advantage over conventional pearlitic rails. Therefore, the investig...

Surface damages caused by the impact of flying objects are important factors responsible for fatigue performance degradation of high-speed railway axles, both qualitative and quantitative assessment of these damages are necessary for the maintenance of these axles. In this paper, cubical projectiles were used to reproduce actual damages on S38C axl...

There are many old riveted highway and railway bridges, constructed 100-150 years ago in Europe and North America. In Portugal, it is counted that about 100 riveted bridges, which were built based on traffic intensity and vehicle weight, are no longer suitable nowadays. However, mainly due to economic reasons, those riveted bridges are still in ser...

The paper presents the results of experimental research on polyurethane materials used in car suspension systems. Taking into account the frequency of maintenance and the number of replacement metal-rubber bushings on the market, the authors considered it reasonable to carry out their tests of materials with different hardnesses of 80 and 90 ShA us...

Although cooling at ambient temperature is widely used and is said to be safe and convenient, faster cooling may have an influence not only on the time of the manufacturing process but also on the mechanical response, especially the residual stress. The study aimed to investigate the influence of the cooling rate after curing on the mechanical resp...

The possibility of eliminating of electrically inactive areas from varistor body with maintaining varistor electrical parameters can be achieved by modifying Bi 2 O 3 in such a way that a Bi-rich layer which surrounds the grains of ZnO is as thin as possible and by minimizing of the amount of additives so as not to form electrically inactive areas...

Foreign object damage (FOD) introduced in service, indentations, and nicks encountered during maintenance are typical defects leading to pre-scrap of high-speed railway axles. A comprehensive assessment of the influence of these defects on the structural integrity of axles is critical for ensuring their operation safety with low maintenance costs....

This paper presents the experimental results of composite rebars based on GFRP manufactured by a pultrusion system. The bending and radial compression strength of rods was determined. The elastic modulus of GFRP rebars is significantly lower than for steel rebars, while the static flexural properties are higher. The microstructure of the selected r...

In this chapter, the problem of deterioration of the mechanical properties of metallic structural members is presented. This phenomenon is associated with microstructural changes in the long-term operated structural objects, especially heavy machinery and bridges. The basic mechanisms of degradation are presented and classified. Further, basic rese...

This book chapter intends to provide a fatigue database for some representative materials of old Portuguese metallic bridges (Eiffel, Luiz I, Fão, Pinhão and Trezói). Puddle irons and structural steels are covered, depending of construction year of the bridge. Besides the base materials, also S–N fatigue data of riveted joints made of original rive...

The typical corrosion damages of structural elements of water tower design engineer V. Shukhov in Mykolayiv (Ukraine) were analyzed. The technical state of the old and repair (used for tower renovation) steels after operation during ~110 and 70 years respectively were evaluated. For their validation the metallographic and fractographic investigatio...

This chapter presents and discusses the typical properties of historical structural materials used in civil engineering. In particular, puddle iron and early 20th-century mild steel have been highlighted. The next part of this chapter presents the problem of structural degradation of long-term operated metallic materials (low carbon steel and puddl...

This chapter of book is devoted to the study of the old steels from the elements of different objects of the late XIX century in Poland such as the Sand Bridge, the Main Railway Station and the Central Pomorski Bridge. It was used the metallographic and fractographic studies, determination of mechanical characteristics during tensile and impact tes...

Surface-hardening process of steel materials by robot laser technologies can involve the challenge of modeling the determining process parameters through non-conventional tools in order to evaluate the quality of the heat treatment. In the current study a new method based on fractal geometry, used to determine the microstructural properties of lase...

Racking systems applied in logistics warehouses are built with thin steel sections that are joined by bolted connections. In fully automatic systems, these structures are loaded 7/7 days and 24/24 hours raising fatigue issues due to the cyclic nature of the resulting stresses. According to the current industrial practice, those bolted joints are ti...

Multiaxial fatigue is frequently present on engineering structures and is the cause of many mechanical failures. However, multiaxial fatigue analysis is full of questions and different points of view. Thus, throughout this study, Susmel’s criterion, a recent multiaxial fatigue damage model also known as the Modified Wöhler Curve Method, is presente...

In large companies, warehouse logistics usually include shuttle pallet carriers that are responsible for the transportation of various goods and products. These shuttles run along steel rails, which are usually produced from thin metal sheets that are cold roll-formed into the desired section. These shuttles also work 24 hours a day, 7 days a week,...

Multiaxial stresses are usually present in engineering structures and are often associated to multiaxial fatigue failures. However, multiaxial fatigue is an open topic, full of questions and different points of view. Therefore, an experimental campaign of uniaxial and multiaxial fatigue tests under proportional loading was conducted aiming at evalu...

In the paper, the problem of fatigue crack growth description is discussed in terms of the energy approach. Authors presented energy models based on the strain energy density parameter applied to the fatigue crack growth rate (FCGR) description. The main beneficial results of this approach is a generalization of the FCGR curves independently from s...

Railway bridges are susceptible to fatigue failures, once these bridges are subjected to permanent loading and high variable loads resulting from the passage of trains. [1]. There are several approaches to evaluate the structural component submitted to the fatigue process. The present paper analyses the fatigue failure process based on Hot Spot Str...

Cast iron probably represents one of the most widely utilized constructive materials in our modern industrial world. This is due not only to the excellent mechanical and tribological properties, but also to a certain flexibility of the same. In fact, it can be produced in various types of metal alloy, which differ significantly in properties: from...

The presented work contains experimental results of fatigue crack growth rate in 42CrMo4 steel. All performed investigations were focused on fatigue crack growth rate and fatigue crack closure effect under mode I and mixed-mode (I+II) loading conditions. For the experimental campaign, CTS (Compact Tension Shear) specimens were involved. Steel 42CrM...

The fatigue crack growth laws that include crack closure effects are based on the relationship between the fatigue crack growth rates ( and the effective stress intensity factor ranges. It is well known, that the crack closure phenomenon near the crack tip plays an important role in fatigue life predictions. In this sense, many relations for the qu...

The growing interest in new materials - especially composite materials in the manufacturing and application of reinforcing bars in the building industry - leads to the development of the fatigue database for steel and composite materials. In the presented paper, Authors compare the fatigue endurance and failure mechanism of two different rebars; st...

Nowadays, in the field of logistics engineering, rack structures prepared for automatic shuttles that are responsible for the intensive transportation and storage of various goods and products are used to deal with the logistics of a large warehouse. These shuttles are automated and can work non-stop in a 24/7 economy. In order to move through the...

One of the essential subjects for the pipeline in the sea is the existence of many earthquakes in the sea, and hence, the dynamic deflection of these structures is essential. Hydro-dynamic analysis of nanocomposite pipes with internal and external fluid is presented. The system is under the earthquake dynamic load and the final equations of are obt...

In this article, a new method for complexity determination by using fractals in combination with an artificial intelligent approach is proposed and its application in laser hardening technology is detailed. In particular, nanoindentation tests were applied as a way to investigate the hardness properties of tool steel alloys with respect to both mar...

The paper presents the fatigue tests results of the different samples configurations subjected to the biaxial type of loading. All test were performed for structural steel. The experimental campaign was conducted with non-proportional bending and torsion without and with phase shift equal to ϕ = 0° and 90° for various stress ratios. One-sided restr...

The paper deals with the subject of diagnostics and the quick repairs of long-term operated metallic materials. Special attention was paid to historical materials, where the structure (e.g., puddle iron) is different from modern structural steels. In such materials, the processes of microstructural degradation occur as a result of several decades o...

The paper presents the results of comparative strength tests on reinforced concrete beams with two different types of reinforcement. The test beams had glass-fibre-reinforced-polymer reinforcing bars with transversal stirrups, while the control beams used conventional streel reinforcement. Both groups were prepared with appropriate geometric parame...

This study addresses the fatigue crack growth behaviour of a material from an old riveted steel bridge, the Portuguese Fão Bridge, based on an experimental program of constant and variable amplitude loading tests. The material under consideration is a centenary puddle iron, for which information on fatigue crack growth under variable amplitude load...

In order to ensure the safety and reliability of materials and structures, for example in power and energy systems, structural integrity and lifetime prediction are hot topics of research in these systems. For many countries, currently facing a potential future mismatch between energy production and transformation, an increasing interest is being p...

This book addresses the fatigue behavior of riveted connections from ancient Portuguese metallic bridges as well as the fatigue crack propagation behavior of related materials. Some examples of the fatigue assessment of long-term operated metallic bridges are presented and discussed. The phenomena of degradation is discussed in chapter 2, devoted t...

The paper presents an analysis of mixed-mode fatigue crack growth in bridge steel after 100-years operating time. Experiments were carried out under mode I + II configuration on Compact Tension Shear (CTS) specimens and mode I + III on rectangular specimens with lateral stress concentrator under bending and torsion loading type. Due to the lack of...

p>One key aspect related to structural integrity of bridges is the fatigue behavior of its materials and structural components. Generally, a fatigue crack initiates in zones where there is a concentration of stresses (geometric discontinuities, for example) and then it may propagate at an increasing growth rate leading to structural failure. Experi...