Grzegorz Litak

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• Prof. (PhD 1994, DSc 2002) email:g.litak@pollub.pl
• Head of Department at Lublin University of Technology

The chromium nitride coating is a hard coating used to improve the sliding friction and wear behavior and is applied to engine components in various operating conditions even at an elevated temperature. In this study, chromium nitride was deposited by a physical vapor deposition process onto the cast iron substrate. All tribological tests were perf...

This paper examines the oscillations of a spherical pendulum with horizontal Lissajous excitation. The pendulum has two degrees of freedom: a rotational angle defined in the horizontal plane and an inclination angle defined by the pendulum with respect to the vertical z axis. The results of numerical simulations are illustrated with the mathematica...

As an effective means to overcome the shortcomings of linear systems only performing well near the resonance frequency, monostable piezoelectric energy harvesters (MPEHs) have been investigated widely in the area of energy harvesting. However, it is difficult to achieve a perfectly symmetric potential energy function due to the asymmetries in magne...

This paper presents the results of numerical simulations of a non-linear, tristable system for harvesting energy from vibrating mechanical devices. Detailed model tests were carried out in relation to the system consisting of a beam and three permanent magnets. Based on the derived mathematical model and assuming a range of control parameter variab...

Due to the broadband response characteristics at low levels of excitations, nonlinear multistable systems have garnered a great deal of attention in the area of energy harvesting. Moreover, various performance enhancement strategies of multistable harvesters have been proposed and discussed extensively for systems with perfectly symmetric potential...

A bistable effect on a laminate structure with a piezoelectric patch was tested to harvest kinetic energy. The composite bistable plate was prepared in the autoclave with two different orientations of the glass fibers. The dynamic tests were performed on the universal testing machine using cyclic vertical compression excitation. During the tests, t...

Nonlinear Energy Sinks (NESs) have been successfully deployed to control hazardous stall-induced aeroelastic responses. This study investigates the effectiveness of NES, its parameters and location on airfoil for optimal suppression of stall flutter oscillations. A mathematical model encompassing a pitch-plunge airfoil is considered. A NES is attac...

Non-smooth dynamical systems are integral to many engineering applications, including vibration control, energy dissipation, stability analysis, and nonlinear electronic circuits. The growing interest in this field has led to significant advances in theoretical modeling, computational techniques, and experimental validations, which are reflected in...

The present study investigates the effect of the passive jet control system on the performance of a vibration energy harvester system (VIVEHS). The shape of a bluff body primarily in-fluences the mechanism of vortex shedding and the effect of passive jet control system would impact the dynamic behavior of vortices and result in enhancing or suppres...

We report the experimental results of flow energy harvesting where the bluff-bodies with different shapes of cross-section are mounted at the ends of the cantilever beams. Namely, bluff-bodies as cylinders and rectangles were considered for the interaction with flowing air. The bluff-bodies are coupled through the joint suspension frame where the o...

Nonlinear wind-induced vibration energy harvesters have rich response dynamic behaviors, and diagnosing these response characteristics is crucial for promoting their application. This paper uses the analysis method of “0-1 test” to distinguish response characteristics of bistable and tristable vortex-induced vibration energy harvesters (VIVEHs), an...

Citation: Ambrożkiewicz, B.; Czyż, Z.; Pakrashi, V.; Anczarski, J.; Stączek, P.; Koszewnik, A.; Wendeker, M.; Litak, G. Performance Assessment of a Piezoelectric Vibration Energy Harvester for Hybrid Excitation with Varying Cross Sections. Sensors 2024, 24, 7629. https://doi. Abstract: This paper experimentally examines the influence of hybrid exci...

The aim of this paper is to present a methodology for implementing the high-energy orbits which is still an open problem for nonlinear energy harvesters. To achieve it, this paper presents a new design of system with a flag configuration which potential function is shaped with the use of elastic elements. We have identified the lift force in FEM fo...

https://authors.elsevier.com/a/1k8nx3YtFPxyOm

This paper presents research on a new type of energy harvester consisting of two parts-the classical tristable system based on a flexible beam and permanent magnets, supplemented by the second part: an additional nonlinear support made of ethylene propylene diene monomer (EPDM). This support is used to amplify the vibration amplitude. As part of th...

This paper deals with nonlinear mechanics of an elevator brake system subjected to uncertainties. A deterministic model that relates the braking force with uncertain parameters is deduced from mechanical equilibrium conditions. In order to take into account parameters variabilities, a parametric probabilis-tic approach is employed. In this stochast...

In this investigation, a three-dimensional (3D) axisymmetric potential well-based nonlinear piezoelectric energy harvester is proposed to increase the broadband frequency response under low-strength planar external excitation. Here, a two-dimensional (2D) planar bi-stable Duffing potential is generalized into three dimensions by utilizing axial sym...

In this study, we investigate the nonlinear dynamics of a kinetic energy harvester featuring a single degree-of-freedom magneto-piezoelectric harvester with a double-well potential resonator. A detailed analysis of the simulation results revealed the influence of initial conditions on the average power output as we varied the frequency of the exter...

To improve the energy harvesting performance of flow-induced vibration energy harvesters, this paper proposes the design of the nonlinear multistable wake-galloping energy harvester. The corresponding lumped-parameter model is established to use for theoretical analysis. The homoclinic and heteroclinic orbits of nonlinear bistable and tristable wak...

This article presents the operation of an automatic pine sawn timber inspection system, which was developed at the Woodinspector company and is offered commercially. The vision inspection system is used to detect various wood defects, including knots, blue stain, and mechanical damage caused by worms. A blue stain is a defect that is difficult to d...

The proposed energy harvesting system is based on a rotational pendulum-like electromagnetic device. Pendulum energy harvesting systems can be used to generate power for wearable devices such as smart watches and fitness trackers, by harnessing the energy from the human body motion. These systems can also be used to power low-energy-consuming senso...

Numerical calculations were performed to study the vortex-induced vibration (VIV) of a circular cylinder, which was elastically supported by springs of linear and cubic terms. These simulations were conducted at high Reynolds numbers ranging from 4200 to 42,000. To simulate the cylinder's motion and the associated aerodynamic forces, Computational...

This paper analyzes the dynamics and energy harvesting of a resonantly excited single-degree-of-freedom linear system with an array of pendulums coupled by springs as absorbers. Energy generation along with vibration reduction gives added advantage of generating sufficient electrical energy to powerup portable electronics. Energy harvesting convert...

The development of small-scale and low power consumption devices has been motivating the design of intelligent mechanisms, exhibiting a wide power density spectrum across various external sources. Smart materials come up as an attractive alternative due to their intrinsic multi-coupling between different physical domains. In this context, piezoelec...

The development of small-scale and low power consumption devices has been motivating the design of intelligent mechanisms, exhibiting a wide power density spectrum across various external sources. Smart materials come up as an attractive alternative due to their intrinsic multi-coupling between different physical domains. In this context, piezo-ele...

The paper presents a study of issues related to the identification of a non-linear mathematical model describing dynamics of the temporomandibular joint (TMJ) disc. Based on the tests of real disks, a non-linear model was built and verified, and then numerical simulations were carried out, the purpose of which was to analyze the behavior of the mod...

The article presents the operation of the automatic pine sawn timber inspection system, which was developed at the Woodinspector company and offered commercially. The vision inspection system is used to detect various wood defects, including knots, blue stain, and mechanical damage caused by worms. Blue stain is a defect that is difficult to detect...

Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered devices. To improve the working performance of energy harvesters effectively, a suitable structural design is crucial. This paper proposes a dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system to enhan...

We study the effect of an amplification mechanism in a nonlinear vibration energy harvesting system where a ferromagnetic beam resonator is attached to the vibration source through an additional linear spring with a damper. The beam moves in the nonlinear double-well potential caused by interaction with two magnets. The piezoelectric patches with e...

In this work, we explore the nonlinear dynamics for capturing energy from a device, which is considered support with cantilever beam ferromagnetic containing piezoceramic patches connected to an electrical circuit that collects energy for capture. The free end of the ferromagnetic cantilever beam is under the effect of two magnetic poles, and we co...

Traditional structures adopt a split design with vibration control, energy harvesting and monitoring, which is difficult to meet the needs of technological development. The development of new structure from a single function to a multifunctional integration structure requires that the structure not only has the characteristics of low-frequency vibr...

In this paper, we compare three energy harvesting systems in which we introduce additional bumpers whose mathematical model is mapped with a non-linear characteristic based on the hyperbolic sine Fibonacci function. For the analysis, we construct non-linear two-well, three-well and four-well systems with a cantilever beam and permanent magnets. In...

The phenomenon of amplitude jump usually means the presence of multi-solution ranges and unstable periodic solutions, which has not been fully explored in the field of vortex-induced vibration energy harvesting. In this study, semi-analytical periodic solutions of vortex-induced vibration energy harvesters (VIVEHs) are obtained using the incrementa...

This article classifies the dynamic response of rolling bearings in terms of radial internal clearance values. The value of the radial internal clearance in rolling-element bearings cannot be described in a deterministic manner, which shows the challenge of its detection through the analysis of the bearing's dynamics. In this article, we show the o...

To enhance the broadband performance of the bistable energy harvester under low-level vibrations, this paper proposes a piezoelectric nonlinear energy harvester with dual-coupling beams. The proposed device is composed of a linear energy harvester and a bistable nonlinear energy harvester which are elastically connected by a linear spring. The elec...

The paper presents the application of a new impulse excitation diagram (IED) to help realize high-energy orbits in nonlinear energy harvesting systems. In the case of non-linearity, we can deal with the occurrence of coexisting solutions and the proposed diagram allows for the use of the impulse excitation method in order to change the solution. Fo...

Dynamical systems for kinetic energy harvesting have recently been designed that use nonlinear mechanical resonators and corresponding transducers to create electrical output. Nonlinearities are important for providing a broadband input frequency efficiency, which is necessary to ensure that the output voltage is at a satisfactory level in the case...

Dynamical systems for kinetic energy harvesting have recently been designed that use nonlinear mechanical resonators and corresponding transducers to create electrical output. Nonlinearities are important for providing a broadband input frequency efficiency, which is necessary to ensure that the output voltage is at a satisfactory level in the case...

The basic types of multi-stable energy harvesters are bistable energy harvesting systems (BEH) and tristable energy harvesting systems (TEH). The present investigations focus on the analysis of BEH and TEH systems, where the corresponding depth of the potential well and the width of their characteristics are the same. The efficiency of energy harve...

Paper presents computer simulations conducted to study the influence of the configuration of an energy harvesting system with tunnel mechanical characteristics in terms of its energy generation efficiency. In this context, numerical simulation experiments were carried out to assess the impact of physical properties and initial conditions on the occ...

This paper proposes a novel vortex-induced vibration piezoelectric energy harvester attached to two asymmetrical splitter plates (VIVPEH-S), which aims at converting the vibration mode from vortex-induced vibration (VIV) to galloping and improving the energy harvesting efficiency. The conceptual designing of VIVPEH-S with two asymmetrical splitter...

Energy harvesters based on non-linear systems are promising devices for extracting energy from mechanical vibrations. This paper presents a new design of energy harvester consisting of two coupled nonlinear systems; the Duffing oscillator and a system with quasizero stiffness. A numerical analysis of the dynamics of the harvester is carried out, pr...

In the paper, flow boiling in three parallel minichannels with a common inlet and outlet area was examined. The synchronization between flow distributions in minichannels was analyzed in local area (image analysis) and as the process of the synchronization between inlet and outlet pressure fluctuations. These processes were studied using cross recu...

This paper presents the results of numerical simulations of a non-linear, bistable system for harvesting energy from ambient vibrating mechanical sources. Detailed model tests were carried out in relation to the system consisting of a piezoelectric beam with additional springs attached. Based on the springs selection symmetry of potential wells was...

A nonlinear energy harvester with asymmetric potential wells is studied numerically. An energy transducing piezoelectric patch is attached to the cantilever elastic beam to harvest kinetic energy of the moving frame. To obtain an asymmetric effect in the double well potential induced by permanent magnets, an elastic ferromagnetic beam resonator mis...

This article demonstrates the possibility of energy harvesting by mistuned pendulums with torsional coupling. Two pendulums of different lengths with coils and magnets at the pivots are used as electromagnetic harvesters. The ambient energy source to the system is considered in the form of harmonic base excitations. Torsional coupling is achieved b...

In this work, we analyzed the nonlinear fractional dynamics in the equations of motion of a bar coupled to support under the effect of a potential described by two equally spaced magnetic poles. We also considered Bouc–Wen damping in the equations of motion. For external force vibrations, we considered an equation of a non-ideal motor based on the...

Interpretation of acceleration time-series from rolling-element bearings is sometimes challenging if no prior knowledge of the system is available. The evaluation must adapt operational conditions or the actual value of operational parameters. In our analysis, we apply the machine learning methods and statistical indicators in the diagnosis of dyna...

The subject of the research contained in this paper is a new design solution for an energy harvesting system resulting from the combination of a quasi-zero-stiffness energy harvester and a two-stage flexible cantilever beam. Numerical tests were divided into two main parts-analysis of the dynamics of the system due to periodic, quasiperiodic, and c...

The influence of heat, developed in process, on the performance of bearings applied in rotational systems is often studied. In the present work, the influence of thermal expansion on the reduction of the radial clearance after assembly and the dynamics of the self-aligning ball bearing are experimentally studied. The course of the temperature chang...

We use friction to simultaneously damp and excite a pendulum system. A Froude pendulum attached to a suspension shaft is subjected to a frictional load. We investigate two types of response of the system: regular and chaotic responses, depending on the excitation frequency. A transient chaotic solution was also obtained. We identify the motions usi...

We examine the nonlinear response of two planar pendula under external and kinematic excitations, which are very relevant as paradigmatic models in nonlinear dynamics. These pendula act under the action of an additional constant torque, and are subjected to one of the following excitations: a further external periodic torque, and a vertically perio...

In this paper, an electronic circuit based on Macek equations was developed in which the phenomenon of hyperchaos was observed. Synchronization of signals was applied using the technique optimal linear feedback control (OLFC) and embedded in digital signal processor (DSP), with the circuit with hyperchaotic behavior as a master system and a periodi...

PurposeThe present work examines the influence of additional moderate amplitude high-frequency (HF) excitation on energy harvesting (EH) in the inertially excited bistable Duffing-type harvester with nonlinear damping.Method By introducing the slow and fast time scale we split the dynamics of the electromechanical system and obtain the effective ha...

With the advent of technology miniaturization, portable electronic devices are evolving at a rapid pace, especially in the field of wireless sensor networks for IoT applications. On the contrary, battery technology has not seen a similar growth in miniaturization. Also, frequent replacement of batteries is challenging for devices located in remote...

In this work, we present a quantitative and qualitative analysis of the dynamic response of ball bearings dependent on radial internal clearance. We measured the vibrations of a rotating system based on self-aligning ball bearings for different clearances and rotating speeds. The analysis of vibration spectra was conducted considering a set of diff...

Hydroxyapatite possesses desirable properties as a scaffold in tissue engineering: it is biocompatible at a site of implantation, and it is degradable to non-toxic products. Moreover, its porosity enables infiltration of cells, nutrients and waste products. The outcome of hydroxyapatite implantation highly depends on the extent of the host immune r...

In this work, modeling and nonlinear analysis of an energy harvesting system from vibrating mechanical devices are presented. Detailed model analyses are carried out for the system consisting of two flexible beams interconnected mechanically through elastic and dissipative elements and electrically by circuits through piezoelectric patches. During...

Vibration mitigation is atracting lot of researcher to safegaurd machines and structurs. Energy harvesting along with vibration mitigation gives added advantage of generating enough electrical energy to powerup sensors. Vibration energy harvesting converts vibration into useful electrical energy using suitable trnsduction method. Nonlinear energy s...

Broadband frequency energy harvesting systems are based on nonlinear resonators. Ambient kinetic energy is transformed to electric energy by a piezoelectric patch installed on the elastic beam. In this paper we study a bistable energy harvester consisted of the resonator with some nonlinearities induced by magnets. The system is excited with the co...

In this paper, a study on modelling energy harvesting efficiency of a quasi-zero stiffness system is presented. Mechanical characteristics of the system are identified, and the effect of its stiffness and geometry on the function describing energy potential barrier is determined. It has been shown numerically that an increase in equivalent stiffnes...

We investigated the mathematical model of a ferromagnetic cantilever beam containing patches of piezoceramic materials for vibration energy harvesting. The beam is coupled to a hysterical Bouc-Wen damper. One of the beam end is clamped to the vibrating frame. It contains the piezoelectric patch coupled to an electric circuit for energy transduction...

Ambient vibration conditions greatly influence the response of nonlinear energy harvesters. Recently, simulations and experiments have verified that tristable energy harvesters have excellent energy harvesting performance and complex nonlinear characteristics, which are important in broadening their effective operating frequency range. The response...

The subject of the model research contained in this paper is a new design solution of the energy harvesting system with a star-shaped structure of elastic elements and variable configuration. Numerical experiments focused mainly on the assessment of the configuration of elastic elements in the context of energy harvesting efficiency. The results of...

In this paper, a study on modelling energy harvesting efficiency of a quasi-zero stiffness system is presented. Mechanical characteristics of the system are identified, and the effect of its stiffness and geometry on the function describing energy potential barrier is determined. It has been shown numerically that an increase in equivalent stiffnes...

We propose a system for collecting energy based on a structure with two bars, in which one of its ends is embedded in the moving system frame and the other end is under the action of magnetic fields. The recessed tips are connected to an electrical system in which a resistor generates a voltage due to the current produced by the PZT deformations. H...

Dual Energy X-ray Absorptiometry (DXA) is a tool that allows the assessment of bone density. It was first presented by Cameron and Sorenson in 1963 and was approved by the Food and Drug Administration. Misplacing the femoral neck box, placing a trochanteric line below the midland and improper placement of boundary lines are the most common errors m...

The piezoelectric energy-harvesting system with double-well characteristics and hysteresis in the restoring force is studied. The proposed system consists of a bistable oscillator based on a cantilever beam structure. The elastic force potential is modified by magnets. The hysteresis is an additional effect of the composite beam considered in this...

This chapter presents the results of computer simulations of the system of energy harvesting from vibrating mechanical devices. Detailed model tests were carried out for the system of cantilever beams coupled with elastic elements. The end of one vibrating element is loaded with a permanent magnet, which defines a non-linear potential characteristi...

In this work, the investigation of energy harvesting for a U-frame-type (portal frame) structure is presented. The structure is considered as a composite made out of a Shape Memory Alloy (SMA), accounting for a non-ideal DC motor of limited power supply attached to its rigid body. The energy harvesting is carried out using a piezoelectric material...

Tribological behaviour is characterized by the strong nonlinear effects in its response, which are hardly identified with standard signal processing methods. One of the challenges in the analysis of wear phenomena is identification of its propagation and potential quantification. In our study, we propose application of wavelet-based methods, i.e. c...

This paper presents the results of modelling a new nonlinear multi-stable QZEH (quasi-zero energy harvester) system for harvesting energy from vibrating mechanical devices. Detailed tests were carried out on the system model, which consisted of a beam and a system of springs, which were used to determine the potential of a quasi-flat well. Two-dime...

The special issue entitled "Mathematical modelling, nonlinear dynamics, bifurcation, synchronization and control of mechanisms driven by power supply," published by The European Physical Journal: Special Topics (EPJST), aims to bring into discussion works involving nonlinear and dynamic and chaotic behaviors, which are frequently found in mechanica...

This paper analyzes the energy efficiency of a Micro Fiber Composite (MFC) piezoelectric system. It is based on a smart Lead Zirconate Titanate material that consists of a monolithic PZT (piezoelectric ceramic) wafer, which is a ceramic-based piezoelectric material. An experimental test rig consisting of a wind tunnel and a developed measurement sy...

This paper investigates the nonlinear dynamics of a flexible tyre coupling via computer modelling and simulation. The research mainly focused on identifying basins of attraction of coexisting solutions of the formulated phenomenological coupling model. On the basis of the derived mathematical model, and by assuming ranges of variability of the cont...

In the present work, a method for the analysis of short time intervals in ball bearings is proposed. We study the effect of the internal clearance on the dynamics of ball bearings using recurrence plots and the recurrence quantification approach. In the proposed method, we focused on the analysis of dynamic states generated from the 2-DOF mathemati...

In this paper, the dynamical behavior of a four-dimensional magnetohydrodynamic model, consisting of a generalized Lorenz model, is investigated. A nonlinear dynamical analysis is performed using Lyapunov exponents and bifurcation diagrams, focusing on the chaotic and hyperchaotic behaviors associated with the bifurcation parameter \(\left( k_{1} \...

The paper proposes and investigates nonlinear vibrations mitigation strategies of an externally excited pendulum. This problem is highly relevant to the crane’s payload behavior, which dynamics is typically described by a nonlinear pendulum model. Currently, there are various active control strategies to mitigate swinging vibrations of the payload...

In the paper, a new 3D energy harvesting system is provided. This work discussed the Lagrange approach to derive the differential equations of motion in the case of energy harvesting systems. An electromechanical system consists of a mechanical resonator, a piezoelectric transducer and electrical circuit with the load resistor. A flexible slender r...

In this paper, the frequency broadband effect in vibration energy harvesting was studied numerically using a quasi-zero stiffness resonator with two potential wells and piezoelectric transducers. Corresponding solutions were investigated for system excitation harmonics at various frequencies. Solutions for the higher voltage output were collected i...

This work aimed to investigate the performance of the process of capturing electricity through piezoelectric ceramic materials, installed in one and two elastic beams due to the action of magnetic field forces, of non-linear behaviour and subject to different forms of excitement of the environment.