Sergey N. Shevtsov

• DrSc
• Head of Department at Southern Center of Russian Academy of Science

In this article, we investigate the effectiveness of low-frequency acoustic non-evaluation (NDE) and localization of possible delaminations that occur in a multilayered carbon fiber reinforced plastic (CFRP) with transversal isotropy of the material. The experiments were carried out with a flat square panel, in which wave motions were excited by a...

The article experimentally and numerically investigates the effectiveness of low-frequency acoustic nondestructive evaluation (NDE) and the localization of possible delaminations in a multilayered carbon fiber reinforced plastic (CFRP) panel with transverse isotropy of the material. The experiments were carried out on a flat square panel, where wav...

The problems of rational design, manufacturing of the forming equipment made from polymer composite materials and its use in the molding of thin-walled composite structures by the vacuum infusion technology are considered. Taking into account the requirement for a minimum of warping deformations of the molded composite structure caused by residual...

The article presents the results of modeling various modes of vacuum infusion molding of thin-walled polymer-composite structures of arbitrary geometry. The small thickness of the manufactured structures and the fixation of their back surface on the rigid surface of the mold made it possible to significantly simplify the process model, which takes...

In this paper, we present the results related to the development of a technique for low-frequency acoustic non-destructive testing of layered composite structures. The main goal was to detect and pinpoint potential bundles in such structures. To do this, we used as an object of research a manufactured carbon fiber panel consisting of eight layers,...

Process simulation is frequently adopted to facilitate the optimization of the resin transfer molding process. However, it is computationally costly to simulate the multi-physical, multi-scale process, making it infeasible for applications involving huge datasets. In this study, the application of K-nearest neighbors and artificial neural network m...

Vacuum infusion technologies are mainly used in the production of lightly loaded composite structures due to the relatively small and unevenly distributed of the fiber volume fraction and a significant variation in the wall thickness of finished parts, which is due to a significant internal pressure gradient in the preform upon completion of the in...

Marginal spectrum (MS) feature information of humpback whale vocalization (HWV) signals is an interesting and significant research topic. Empirical mode decomposition (EMD) is a powerful time–frequency analysis tool for marine mammal vocalizations. In this paper, new MS feature innovation information of HWV signals was extracted using the EMD analy...

In the paper, we proposed a 2 × 2 direct mapping multi-input multi-output based generalized frequency division multiplexing (GFDM) low density parity check (LDPC) code underwater image transmission scheme (UITS). The adaptive 4 quadrature amplitude modulation (QAM) and 16 QAM modulations, were integrated into the proposed UITS. The performances of...

The main purpose of this study was to develop a model for predicting the quality of holes drilled in the root part of the spar of helicopter main rotor blades made of glass fiber-reinforced plastic (GFRP)-Ti multilayer polymer composite. As the main quality criterion, delaminations at the entry and exit of the drill from the hole were taken. In the...

One of the reasons for the insufficiently wide use of the low-cost and low-labor vacuum infusion process in the production of polymer composite structures is the uneven distribution of pore pressure, porosity, and preform thickness at the final stage of filling the preform with liquid resin. This article presents the results of a theoretical study...

The main purpose of this study was to develop a model for predicting the quality of holes drilled in the root part of a spar of helicopter main rotor blades made of the Glass Fiber Reinforced Plastic (GFRP)-Ti multilayer polymer composite. As the main quality criterion, delaminations at the entry and exit of the drill from the hole were taken. In t...

The increasingly widespread use of vacuum assisted technologies in the manufacture of polymer-composite structures does not always provide the required product quality and repeatability. Deterioration of quality most often appears itself in the form of incomplete filling of the preform with resin as a result of the inner and outer dry spot formatio...

In this paper, a low-power underwater acoustic (UWA) image transceiver based on generalized frequency division multiplexing (GFDM) modulation for underwater communication is proposed. The proposed transceiver integrates a low-density parity-check code error protection scheme, adaptive 4-quadrature amplitude modulation (QAM) and 16-QAM strategies, G...

Vacuum assisted molding technologies for the manufacture of composite structures have become more and more popular in the last decade in many industries due to their simplicity, relatively low cost and speed of preparation for production. However, their distribution is limited due to the low stability of the achieved quality indicators (limited por...

Insufficient reliability and repeatability of the vacuum-infusion molding of polymeric-composite structures, especially of complex shapes, limit the practical application of this relatively simple and low-cost process. These circumstances make it relevant to use the method of its computer simulation with the possibility of numerical optimization. T...

Increasing the quality and reliable reproducibility of large-size composite structures molding using the vacuum infusion method, which is gaining popularity in various industries, is achieved in practice through numerous tests by try and errors that require significant costs and time. The purpose of these tests is to determine the layout of the por...

Increasing the quality and reliable reproducibility of large-size composite structures molding using the vacuum infusion method, which is gaining popularity in various industries, is achieved in practice through numerous tests by try and errors that require significant costs and time. The purpose of these tests is to determine the layout of the por...

In the paper, a 2 × 4 space time block code (STBC) based filter bank multicarrier (FBMC)-low density parity check (LDPC) code underwater image communication technology (UICT) is proposed. The adaptive binary phase shift keying (BPSK) modulation and four offset quadrature amplitude modulation (4-OQAM), are integrated into the proposed UICT. The perf...

The vacuum assisted technologies of composite parts manufacturing are becoming very popular owing to their relative simplicity and inexpensive equipment. They are implemented in the production of aircrafts, rotorcrafts, ships, cars and wind turbine blades. Unfortunately, in many cases this technology does not provide sufficient repeatability and qu...

Technologies for the production of polymer composites based on vacuum infusion have attracted more and more attention of engineers and scientists due to the simplicity and low cost of technological equipment. However, the industrial use of these technologies requires a large number of preliminary trial tests to ensure the stable quality of manufact...

The production of composite structures using vacuum infusion technology is used in various industries due to its low cost, labor intensity, and simplicity of the required equipment. However, ensuring the quality of the process requires a significant investment of time using the trial and error method, the consumption of expensive materials, which m...

The technologies of composite structures manufacturing using vacuum broad their application in the production of large-sized structures of good quality a in aviation, shipbuilding, automotive, wind energy and other industries, due to its low workload, simplicity of the necessary equipment and the satisfactory environmental conditions. The vacuum in...

Featured Application Polymeric composites: modeling, optimization, technology. Abstract This paper considers a new approach to the modeling of the vacuum infusion process at the manufacturing of three-dimensional composite parts of complex shape. The developed approach and numerical methods focus on reliable prediction with needed accuracy and eli...

This paper addresses investigation of guided-wave excitation by angle-beam wedge piezoelectric (PZT) transducers in multilayered composite plate structure with orthotropic symmetry of the material. The aim of the present study is to determine the capability of such actuators to provide the controlled generation of an acoustic wave of a desirable ty...

This paper addresses investigation of guided-wave excitation by angle-beam wedge piezoelectric transducers in multi-layered composite plate structure with orthotropic symmetry of the material. The aim of the present study is to determine the capability of such actuators to provide the controlled generation of an acoustic wave of a desirable type wi...

This paper considers a new approach to the modeling of the vacuum infusion process at the manufacturing three-dimensional composite parts of complex shape. The developed approach and numerical methods are focused on the reliable prediction with the needed accuracy and elimination the unrecoverable defect of composite structure such as the dry spots...

In this paper, a direct-mapping (DM)-based multi-input multi-output (MIMO) filter bank multi-carrier (FBMC) underwater acoustic multimedia communication architecture (UAMCA) is proposed. The proposed DM-based MIMO-FBMC UAMCA is rare and non-obvious in the underwater multimedia communication research topic. The following are integrated into the prop...

This study presents some results of the experimental and numerical investigations on the generation of Lamb waves using a piezoelectric angle beam actuator with wedge. The experiments were carried out on isotropic plastic panel. Experimental study was performed using the Olympus V414-SB angle beam transducer. For the numerical part of the current r...

This paper is motivated by the goal of developing improved technique for the Nondestructive Evaluation (NDE) of the load carrying composite structures using Lamb waves generated by the surface mounted piezoelectric (PZT) transducers. The Lamb waves are used in the active NDE systems due to their ability to propagate over large distances in the thin...

The processes of the vacuum assisted composite fabrication often named as VARTM that are intensively studied in aircraft, shipbuiding, automotive industries involve the placement of preform - dry fabric or layered glass / carbon fibers into the mould, which is inserted in a vacuum bag. A liquid resin flows into dry preform through the resin inlet,...

The paper aims to develop improved acoustic-based structural health monitoring (SHM) and nondestructive evaluation (NDE) techniques, which provide the waves directivity emitted by the angle beam wedge actuators in thin-walled structures made of plastic materials and polymeric composites. Our investigation includes the dispersive analysis of the wav...

The paper is aimed to develop an improved acoustic-based Structural Health Monitoring (SHM) and Non-Destructive Evaluation (NDE) techniques, which provide the waves directivity emitting by the angle-beam wedge actuators in the thin-walled structures made of plastic materials and polymeric composites. Our investigation includes the dispersive analys...

The paper is aimed to develop an improved acoustic-based SHM and NDE technique, which provides the waves directivity emitting by the angle-beam wedge actuators in the thin-walled structures made of plastic materials and polymeric composites. Our investigation includes the dispersive analysis of the waves that can be excited in the studied plastic p...

The article investigates the Lamb wave generation by the surface bonded circular actuator and wave propagation within the orthotropic Carbon Fiber Reinforced Plastic (CFRP) plate considering the anisotropy of the material elastic and damping properties. The first part of our investigation includes experimental determination of the elastic propertie...

This paper investigates the Lamb wave generation by the surface bonded circular piezoelectric (PZT) actuator and wave propagation within the orthotropic Carbon Fiber Reinforced Plastic (CFRP) plate considering the anisotropy of the elastic and damping properties of the materials; existence of the adhesive layer; and dependence of the interfacial st...

Численными методами проведен анализ напряженного состояния выравнивающего заполнителя ЗП-1 (эпоксидная композиция с наполнителем из диоксида титана) при ремонте коррозионного повреждения верхней панели средней части крыла методом установки накладки. Подтверждены данные невозможности существования абразива в пакете панель-накладка из-за разрушения к...

The subject of optimum composite structures is a rapidly evolving field and intensive research and development has taken place in the last few decades. Therefore, this book aims to provide an up-to-date comprehensive overview of the current status in this field to the research community. The contributing authors combine structural analysis, design...

The subject of optimum composite structures is a rapidly evolving field and an intensive research and development has taken place in the last few decades. Therefore, this book aims to provide an up-to-date comprehensive overview of the current status in this field to the research community. The contributing authors combine structural analysis, desi...

This paper proposes a direct mapping (DM) filter bank multicarrier (FBMC) based underwater transmission scheme for audio signals. Figure 50.1 schematically shows the proposed FBMC scheme, and DM transmission technology, low-density parity-check (LDPC) channel coding, adaptive binary phase shift keying (BPSK) modulation or offset quadrature amplitud...

In this paper, the method of multicriteria optimization of cantilever PEG with added mass is presented. The optimization process was divided into several stages, which made it possible to significantly reduce the volume of calculations. The main goal of the optimization was to adjust the PEG to a given operating frequency of 26 Hz. As a result, a s...

In the paper there is shown an essence of the stabilizing machining of parts and the ways for its realization are presented, the methods of processing system development, parameters computation of the controlling impact of stabilizing processing are offered, and there are given recommendations for manufacturing equipment design.

The main requirements for high loaded composite structures experiencing the forces and torques with varied intensity and orientation, are the specified mechanical stiffness to prevent the inadmissible deformations and some structural failure. Examples of these structures are aircraft spars, stringers, wing panels etc. Usually, such parts are manufa...

This paper proposes a filter bank multicarrier (FBMC)-based underwater transmission scheme for voice and image signals. In this scheme, FBMC transmission technology, low-density parity-check (LDPC) channel coding, adaptive binary phase shift keying (BPSK) modulation or offset quadrature amplitude modulation (OQAM), and a power assignment mechanism...

The vibrations and noise experienced in a helicopter are mainly caused by periodic forces generated in forward flight by the main rotor due to blade vortex interaction (BVI) and high Mach numbers at the advancing blade. These vibrations are transferred through the rotor hub and the gearbox into the fuselage and this limits the operator’s capability...

In recent years, the research on piezoelectric transducers of mechanical energy into electrical energy has been actively developed. This type of transducer is called a piezoelectric generator (PEG). Basic information about PEGs, as well as the problems arising at the development stages of energy harvesting devices, was provided in the review papers...

The well-known classification of damage includes five levels [49, 146]. The first level consists of detection of defects in a construction without specifying their parameters. The second level determines the location of defects in construction elements. The third level assesses the degree of danger that the damage expresses. The fourth level is the...

This section describes an experiment to determine the performance of a laboratory sample of a cantilever-type piezoelectric generator (PEG). The test set-up, experimental procedure, and experimental data are presented. In addition, the results of the mathematical model described in the previous chapter are compared with the data obtained during the...

In a direct problem, steady-state vibrations of an elastic body are considered in a region with boundaries and they are described by the following boundary-value problem:

Chapter 6 considered examples of rod constructions with defects, as well as algorithms for identifying the parameters of the defects. For early identification of the defect, based on the presented approaches, it is necessary to use automated diagnostic measuring systems. At the same time, technical diagnostics of complex systems (e.g., industrial o...

To study the flexoelectric effect, a three-point excitation model for a piezoelectric element with a proof mass at its center was selected. This type of excitation occupies an “intermediate” place between cantilever- and stack-type PEGs. The axial action of the proof mass along the center of the plate leads to an elastic deflection (see Fig. 3.1),...

Abstract Purpose - The purpose of this paper is to develop the multiobjective optimization approach and its numerical implementation to synthesis the model-base control for the part curing at autoclave processing, which supply the stability and uniformity of the structure and mechanical properties of the material within the cured composite part. D...

This book presents new approaches to R&D of piezoelectric actuators and generators of different types based on established, original constructions and contemporary research into framework of theoretical, experimental, and numerical methods of physics, mechanics, and materials science. Improved technical solutions incorporated into the devices demon...

The paper studies a problem of optimal control synthesis for curing a large composite structure using open die moulding in an autoclave. The necessary control should eliminate early hard skin formation, emergence of resin-rich or resin-dry areas, insufficient consolidation, and uneven cure. This purpose is achieved through providing uniform distrib...

In the paper, the intrinsic mode function (IMF) features of Brain-computer interfaces (BCI) FP1 electroencephalogram (EEG) signals for cerebral palsy (CP) using empirical mode decomposition (EMD) methods were analyzed. The BCI FP1 EEG signals for CP and health, were decomposed into nine IMFs and one residual function (RF), respectively. \( IMFERTE_...

In this paper, a unique analysis method for sperm whale clicks based on Hilbert-Huang transform (HHT) is proposed. Four sperm whale click samples with durations of 10 ms (defined as click I), and four sperm whale click samples with durations of 5 ms (defined as click II) were illustrated. These click samples were recorded in the Mediterranean Sea b...

The main requirements for aircraft glass/carbon fiber shell-like cowls, which are exposed to non-uniform air pressure, are the specified mechanical stiffness to withstand the acting air pressure and reduce the level of noise caused by the airflow-induced vibrations at the constrained weight of the part. To increase the stiffness of the cowl the opt...

One of the main goal in aircraft structures designing isweight decreasing and stiffness increasing. Composite structures recently became popular in aircraft because of their mechanical properties and wide range of optimization possibilities.Weight distribution and lay-up are keys to creating lightweight stiff strictures. In this paperwe discuss opt...

The ability of dielectric analysis (DEA) to continuously monitor the ion viscosity and loss factor of the resin during polymerization not only for the small specimens but also for the large composite structures, is a reason of increasing interest of the engineers and scientists working, especially, in the area of aircraft technology. This growing a...

The most comprehensive endurance characterization of high-strength polymeric composites subject to the external environmental action (humidity, cyclic temperature changes, and ultra violet radiation) can be obtained at the compressive testing of the material's samples. Reinforcing fibers that are directed at acute angles to the part (or specimen) a...

This paper presents the method to improve the performance of underwater transducers based on the porous piezoelectric ceramics. The Pareto-based approach has been used for the optimization of two types of devices: multilayered projector with an active layer made of porous piezoe-lectric ceramics and the membrane-type hydrophone with a perforated ac...

The glass/carbon fiber composites are widely used in the design of various aircraft and rotorcraft components such as fairings and cowlings, which have predominantly a shell-like geometry and are made of quasi-isotropic laminates. The main requirements to such the composite parts are the specified mechanical stiffness to withstand the non-uniform a...

The paper presents an optimal control synthesis for curing shell-like composite structures using open dies in an autoclave. The control synthesis is a multi-objective optimization problem where minimization objectives are deviations of temperature and degree of cure within a cured part, considering constraints imposed by thermo-kinetic properties o...

1. Abstract In this paper we study an optimization problem for the two-stage cure process control that can provide the best quality of the shell-like composite part cured in an autoclave for the acceptable processing time. We consider this process using an example of composite cowling with varying wall thickness. The designed control law should pre...

The paper studies a problem of optimal control synthesis for curing the shell-like composite structure using open die molding in an autoclave. The necessary control should eliminate early hard skin formation, emergence of resin-rich or resin-dry areas, insufficient consolidation, and uneven cure. This purpose can be achieved through providing unifo...

The method for determining the mechanical properties of unidirectional fiber reinforced and layered composite materials has been developed. This method is based on finite element modeling of representative volumes of composite materials, and solving some boundary value problems for them. Finite element modeling was carried out in ANSYS CAE package....

This paper highlights the electric energy harvesting system that consists of piezoelectric (PZT) stack transducer which is excited by random mechanical oscillating force and charges the Li-Ion battery. This battery is a power supply for LED lamp lighting. A very big electric capacitance of the multilayered PZT stack affects on the electric energy f...

Harvesting of mechanical energy generated by the moving cars and trains is a vigorous field of researches because such harvested energy can supply the electric and electronic devices with low power consumption. For instance, the energy harvesting systems that are based on the PZT stack transducers can be effectively used for lighting the road secti...

For two kinds of defects – delamination and transversal failure in the multilayer composite the damages detection method is proposed. The inverse geometrical problems of crack's parameters reconstruction were formulated as a sequence of boundary integral equations (BIE). These boundary integral equations were derived on the basis of the principle o...

В работе рассмотрена проблема синтеза оптимального управления двухстадийным процессом полимеризации в автоклаве композитной конструкции с геометрией типа открытой оболочки переменной толщины. Синтезируемый закон управления температурным режимом должен исключить преждевременное отвердевание поверхности полимеризуемого препрега, возникновение областе...

The work objective is to study the impact of the drill design value and geometrics on the quality of the processed holes, the efficiency, and the machining dynamics of the high-strength polymer composite - fiberglass plastic reinforced by titanium foil. Packs of the reinforcing layers made from the titanium foil or carbon fiber tapes are often used...

This paper presents the numerical method and results of the structural optimization of the wind turbine blade’s mounting zones to diminish and flatten the stress distribution at the action of the wind load on the blade. The blade, which has the stiff carbon/epoxy composite skin and less stiff lightweight core body, is mounted by two spokes to the r...

This paper examined five Berardius Bairdii whistle samples and one referred sample, denoted as ws1(t), ws2(t), ws3(t), ws4(t), ws5(t), and rs1(t), respectively. McDonald, [1] recorded these samples in 1994 at 44° 16.1′ N, 130° 26.8′ W. The current study examined the Hilbert-Huang Transformation (HHT) based time-frequency features of the ws1(t), ws2...

In present study the influence of non-uniform polarization on the electro-mechanical properties of a three-layered piezoelectric transducer is investigated. We suggest that nonuniform polarization field with certain disposition of electrodes can be lead to increased efficiency of the transducer. Finite element package ACELAN was used to solve modal...

Presentation on 3rd European Conference on Renewable Energy Systems

Draft version of book chapter, which is preparing for NOVA science publ.

Draft paper sent to 3rd. European Conference on Renewable Energy Systems, Antalya, TURKEY

1. Introduction-Technology of manufacturing the solid semiconductors, which last time are widely used in wideband electronic devices, attracts an attention both of engineers and scientists. In practice of preparing solid electrolytes in the form of polymer-matrix composite materials, where polymer is a binder, polyvinyl alcohol (PVA) or its derivat...

This work, which has been carried out for defects in aircraft structures diagnosis, is considering of measurement errors, different accelerometers positioning and numerical differentiation of the natural vibrations mode shapes as the sources of uncertainty, which affects on the crack identification results. A physical theory to solve the forward id...

The fabrication of high loaded aircraft polymeric composite parts requires tools such as heated closed-mold to which a pressure is applied at the correct gelation stage of the resin. The curing process includes the placing of a premixed compound in the mould, a pre-warming to the resin viscosity reaches a minimum, next applying of pressure to remov...

: A key aspect of an energy harvesting system is the power electronic circuitry, which interfaces the piezoelectric (PZT) device with the electric load, as a well-designed circuit can increase the amount of energy harvested. Many different circuit topologies have been proposed and studied to achieve this function. Among these types of circuits are...

The method suggests the use of the dependence for Timoshenko beam's deflection, which takes into account the interlaminar shear [3] (1) (2) where P is the applied force, α-is a coefficient that depends on the beam cross-section (1.2 for rectangular form), I x is the moment inertia of cross-section, E f ,-fictive elastic module, which is joined with...