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1

Development of a dynamic vibration absorber in the form of a variable inertia pendulum

Loch Piotr, Bugajewski Karol, Przybyłowicz Piotr, Chiliński Bogumił

Journal of Applied Mathematics and Computational Mechanics

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2025

|

Vol. 24, nr 4

37--50

EN

Nowadays, to maximize space utilization, multi-story buildings are designed to occupy as little surface area as possible. However, the high slenderness of these struc tures makes them susceptible to forces caused by factors such as wind and tectonic plate movements. Prolonged exposure to vibrations reduces the building’s lifespan and leads to its degradation. To minimize the impact of vibrations while maintaining slenderness and relatively low structural rigidity, a solution in the form of a dynamic vibration absorber can be applied. Structures already use absorbers in the form of pendulums, as seen in the Taipei 101 skyscraper, for example. The subject of study is an absorber in the form of a pendulum with a variable moment of inertia, achieved by extending the cable, which allows the structure to adapt to current forces. This significantly reduces the time of exposure to harmful influences. A skyscraper model with a variable-length pendulum was developed and analyzed through simulations, confirming the hypothesis of a significant reduction in exposure.

2

Analiza numeryczna odpowiedzi podłoża budowlanego w warunkach wymuszeń dynamicznych od ruchu pojazdów

Okroj Paweł, Hulimka Jacek

Inżynieria i Budownictwo

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2025

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R. 81, nr 6

686--691

PL

Jednym z wymuszeń w budownictwie jest efekt ruchu ciężkich pojazdów w sąsiedztwie budynków lub budowli. Zagadnienie jest szerokie, a nawiązujący do niego poniższy tekst porusza jedynie jego fragment, mianowicie analizę numeryczną zachowania się modelu gruntu przy takim obciążeniu. W szczególności rozważono efekty dynamicznej odpowiedzi modelu gruntu w zależności od uwzględnienia/pominięcia tłumienia w gruncie, uwzględnienia/pominięcia obciążenia modelu gruntu obiektem budowlanym oraz od wystąpienia/niewystąpienia rezonansu wymuszenia z drganiami własnymi modelu masywu gruntu. Na tej podstawie sformułowano wnioski jakościowe, odnosząc je do praktyki.

EN

One of the forces in structural engineering is the effect of heavy vehicle traffic in the vicinity of buildings or structures. The topic is broad, and the following text only addresses one aspect of it, namely the numerical analysis of the behaviour of a subsoil model under this type of loading. In particular, the effects of the dynamic response of the subsoil model were analysed depending on the inclusion/exclusion of soil damping, the inclusion/exclusion of the load of the soil model by a building structure, and the occurrence/non-occurrence of resonance of the forcing with the natural vibrations of the soil mass model. On this basis, conclusions were formulated, primarily of a qualitative nature, and related to practice.

3

Numerical prognosis of the dynamic response of the steel rectangular slab under the explosive load

Onopiuk Sławomir, Stolarski Adam, Rekucki Ryszard

Archives of Civil Engineering

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2025

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Vol. 71, nr 2

473--489

EN

The paper presents the methodology for determination the numerical prognosis of the dynamic response of the rectangular steel slab subjected to an explosive load, aimed at thorough preparation of experimental tests. In the presented work, in order to fully describe the parameters of the shock wave impact on the steel slab, an appropriate combination of formulas known in the literature was used. In order to describe the dynamic behavior of the rectangular steel slab, the resources of the ABAQUS computing software were used. The Johnson-Cook constitutive model was used to describe the dynamic behavior of the structural material. An explicit procedure has been used to solve the equations of motion for the slab. The parameters of the shock wave from the explosion of the TNT charge with the assumed mass and the distance of its location from the slab were determined. As a result of the numerical analysis, the results of changes in displacement and acceleration in time were presented, indicating the nature of the very intense and fast-varying dynamic behavior of the slab. Conclusions were also formulated regarding the requirements for the selection of parameters of the sensors recording both the function of real explosion pressure in time and the function of acceleration in time of the slab model during experimental tests.

PL

W artykule przedstawiono metodykę wyznaczania numerycznej prognozy reakcji dynamicznej prostokątnej płyty stalowej poddanej obciążeniu wybuchem, mającą na celu dokładne przygotowanie badań eksperymentalnych. W prezentowanej pracy zastosowano odpowiednią kombinację wzorów znanych z literatury, aby w pełni opisać parametry oddziaływania fali uderzeniowej na płytę stalową. W celu opisania zachowania dynamicznego prostokątnej płyty stalowej wykorzystano zasoby programu obliczeniowego ABAQUS. Do opisu dynamicznego zachowania się materiału konstrukcyjnego zastosowano model konstytutywny Johnsona-Cooka. Zastosowano jawną procedurę rozwiązania równania ruchu płyty. Wyznaczono parametry fali uderzeniowej od wybuchu ładunku trotylu o założonej masie oraz odległości jego położenia od płyty. W wyniku analizy numerycznej przedstawiono wyniki zmian przemieszczeń i przyspieszeń w czasie, wskazując na charakter bardzo intensywnego i szybkozmiennego zachowania dynamicznego płyty. Sformułowano również wnioski dotyczące wymagań dotyczących doboru parametrów czujników rejestrujących zarówno funkcję rzeczywistego ciśnienia wybuchu w czasie, jak i funkcję przyspieszenia w czasie modelu płyty podczas badań eksperymentalnych.

4

Determining a damping coefficient by using a microelectromechanical systems accelerometer for finite element method simulation purposes on a discrete damper example

Flis Leszek, Szwoch Grzegorz, Krawczyk Piotr

Advances in Science and Technology. Research Journal

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2025

|

Vol. 19, no. 6

275--290

EN

This paper introduces a methodology, algorithms, and the achieved results for determining the damping coefficient using a microelectromechanical systems (MEMS) accelerometer, specifically for finite element method (FEM) simulations. The paper not only showcases the results but also employs several independent verification procedures to confirm the validity of the obtained damping coefficient. The determined damping coefficient is presented directly in SI units, making it readily applicable to a specific object, while it is usually given as a percentage. The accuracy of the determined damping ratio was validated through unbiased experiments, an in-house computational Python program. Additionally, to ensure the correctness of the determined damping coefficient, a practical example was provided wherein FEM simulation was executed using a discrete element as a damper within ANSYS LS-Dyna software to corroborate the results. The authors emphasize that the proposed method for determining the damping coefficient is both efficient and can be implemented without the necessity of complex equipment. This novel methodology for assessing a damping coefficient serves as a promising alternative to Rayleigh Damping, which lacks a direct physical correlation. Moreover, it opens up significant possibilities for broader application in various engineering fields, including structural dynamics, vibration analysis, and mechanical system optimization.

5

Mechanical wave damping research in innovative solutions for concrete masonry units

Adamczyk Izabela, Major Maciej, Kalinowski Jarosław

Materiały Budowlane

|

2024

|

nr 8

54--61

EN

The article presents a new type of APS (openwork masonry unit) and WAPS (filled openwork masonry unit) concrete masonry units with a frame made of concrete modified with recycled materials. The technical data of the developed masonry unit and the composition of concrete modified with a mixture of SBR (styrene butadiene rubber) and PET (polyethylene terephthalate) recycling additives, as well as the composition of the composite damping mixture based on these two materials, are given. In order to demonstrate the effectiveness of the developed solution in reducing mechanical vibrations, the influence of the impact of different mechanical wave frequencies on the developed APS and WAPS concrete masonry units was assessed. The test results were presented graphically and showed that filling the holes of a new type of concrete masonry unit with a recycled composite mixture improves its effectiveness in limiting the propagation of mechanical waves in the analyzed range from 8 to 5000 Hz, simultaneously allowing the effective management of recycled materials.

PL

W artykule przedstawiono nowego typu betonowe murowe elementy ścienne APS (ażurowy pustak ścienny) i WAPS (wypełniony ażurowy pustak ścienny) o szkielecie wykonanym z betonu modyfikowanego materiałami recyklingowymi. Podano dane techniczne opracowanego elementu ściennego i skład betonu modyfikowanego mieszanką dodatków recyklingowych SBR (styrene butadiene rubber) i PET (politereftalan etylenu) oraz skład kompozytowej mieszanki tłumiącej powstałej na bazie tych dwóch materiałów. W celu wykazania efektywności opracowanego rozwiązania w redukcji drgań mechanicznych dokonano oceny wpływu oddziaływania różnych częstotliwości fali mechanicznej na opracowane betonowe murowe elementy ścienne APS i WAPS. Wyniki badań przedstawiono graficznie i wykazano, że wypełnienie otworów nowego typu betonowego murowego elementu ściennego recyklingową mieszanką kompozytową poprawia jego efektywność w ograniczeniu propagacji fal mechanicznych w analizowanym zakresie od 8 do 5000 Hz, pozwalając jednocześnie skutecznie zagospodarowywać materiały pochodzące z recyklingu.

6

On the Effects of the Interphase on the Damping of CFRP Structures: an Experimental Investigation

Gasenge Mattia, Valvo Paolo Sebastiano, Aliotta Laura, Lazzeri Andrea

Journal of Technology and Exploitation in Mechanical Engineering

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2024

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Vol. 10, nr 1

1--7

EN

The increased adoption of composite laminates in modern engineering requires advancement in the prediction of their dynamic behavior. Damping is a major design constraint in aerospace structures subjected to cyclic loads. While the effects caused by damping are well known, the mechanisms that cause it at the microscopic level are still unclear on a quantitative basis. Testing of these phenomena requires some difficulties to be overcome, like the contribution of spurious sources. The study focuses on the effects that the interphase has on the damping properties of carbon fiber-reinforced polymer (CFRP) composite structures. Three-phase models are employed to investigate the dependence of damping on the interphase mechanical properties, with a focus on the fiber-matrix interfacial shear strength. The experimental campaign confirms the attended results: in particular, a stronger interphase determines a lower damping of the structure.

7

Influence of Shock Absorber on Electric Axle Vibration in Semi-Trailer

Stembalski Marek, Szydlowski Tomasz, Czarnuch Arkadiusz

Journal of Machine Engineering

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2024

|

Vol. 24, No. 3

119--132

EN

This article describes the results of a study of the effect of a shock absorber on the vibration of an electric axle in a semi-trailer. The dynamic characteristics of three shock absorbers from different manufacturers were determined. They were then installed on the electric axle of a semi-trailer equipped with a measuring apparatus. Test runs were carried out on two types of road surface - a test track with a defined profile and a local road. Each run was repeated for a fully loaded and an empty semi-trailer. These tests were designed to determine the values of the dynamic parameters of the electric axle during operation of the semi-trailer depending on the shock absorber used.

8

Advancing the dynamic properties of a column with variable flexural stiffness in terms of structural mounting damping, external and internal damping

Szmidla Janusz, Jurczyńska Anna

Journal of Applied Mathematics and Computational Mechanics

|

2024

|

Vol. 23, nr 3

109--117

EN

The paper presents an analysis of the influence of damping on the free vibrations of a slender column subjected to a specific load. The analyzed system is characterized by a step-variable geometry modeled by connected prismatic segments. The problem was formulated according to the Bernoulli-Euler theory and solved by the variational method (Hamilton’s principle). Boundary and continuity conditions were determined. The paper shows the influence of different types of damping on the free vibrations of the column, and indicates damping as one of the methods for passive controlling and steering of the dynamic properties. The proposed mathematical and numerical model is universal and can be applied to any variable column shape, taking into account any combination of the occurring damping types.

9

Tests of the Mechanical and Acoustic Parameters of Electric Guitar Bodies

Ryniewicz Andrzej, Pietruch Marcin, Ryniewicz Anna M., Bojko Łukasz

Drewno : prace naukowe, doniesienia, komunikaty

|

2024

|

Vol. 67, nr 214

Art. no. 194995

EN

The aim of this work was to perform a mechanical and acoustic analysis of electric guitar bodies. Sam ples of ash, oak, walnut, lime tree, and fir were selected for mechanical tests - with constant moisture content, made of latewood, and free from defects. The tests were carried out on a Brinell device to determine the hardness of the wood, and on an MCT3 machine from Anton Paar to determine the microhardness and elastic moduli. The elastic properties of wood are determined by its anisotropy and have different values depending on the direction of force in relation to the fibers. The wood showed the greatest stiffness along the fibers; in the case of forces acting perpendicular to the fibers, the stiffness was much lower. Sound transmission tests of selected acoustic parameters were carried out. They involved measuring and analyzing the frequency and damping of vibrations of guitar bodies using a special vibration sensor. The acoustic parameters of a guitar body experimentally made from walnut were compared with those of a mass-produced Ibanez guitar made of ash wood. Each species of wood has its own characteristic blend of physical properties, such as grain structure, density, weight, and strength, which influence the final tonal power of the guitar. The test results of various wood species indicate significant differences in strength and acoustic-resonance properties, which determine the absorption of vibrations, sound amplification, and sound transmission. The use of a specific wood for a guitar body is dependent on the musician’s artistic vision and the purpose of the instrument.

10

Shear modulus and damping ratio of recycled concrete aggregate from cyclic torsional shear test

Gabryś Katarzyna

Roads and Bridges - Drogi i Mosty

|

2023

|

Vol. 22, no. 4

387--398

EN

This study examines the small-strain dynamic properties of three mixtures of recycled concrete aggregate (RCA) using laboratory investigations typical of natural soils, namely cyclic torsional shear (CTS) tests. In order to construct two samples, crushed concrete curbs originating from a demolition site in Warsaw was employed. To create the third sample, crushed concrete from demolished buildings also Warsaw was used, mainly from concrete wall and floor elements. A series of CTS tests were performed to investigate the impact of various parameters, including confining pressure, excitation frequency, and number of vibration cycles on the G−modulus, Gmax−modulus, shear modulus degradation curve G(γ)/Gmax, D−ratio, Dmin−ratio, variation in damping curve D(γ)/Dmin. The resulting stiffness and damping characteristics of the analysed concrete aggregate were compared with those of natural gravel and sand aggregate – natural aggregate (NA). The results collected from the CTS tests indicate that the performance of most RCA is comparable to that of NA and can be used as an unbound granular material (UGM).

PL

W niniejszym badaniu zbadano właściwości dynamiczne przy małych odkształceniach trzech mieszanek kruszywa betonowego z recyklingu (RCA) przy użyciu badań laboratoryjnych typowych dla gruntów naturalnych, a mianowicie badania cyklicznego ścinania skrętnego (CTS). Do wykonania dwóch próbek wykorzystano pokruszone krawężniki betonowe pochodzące z rozbiórki w Warszawie. Do stworzenia trzeciej próbki wykorzystano pokruszony beton z rozebranych budynków, także z Warszawy, głównie z betonowych elementów ścian i podłóg. Przeprowadzono serię testów CTS w celu zbadania wpływu różnych parametrów, w tym ciśnienia ograniczającego, częstotliwości wzbudzenia i liczby cykli wibracji na moduł G, moduł Gmax, krzywą degradacji modułu ścinania G(γ)/Gmax, współczynnik D, współczynnik Dmin, zmianę krzywej tłumienia D(γ)/Dmin. Uzyskane charakterystyki sztywności i tłumienia analizowanego kruszywa betonowego porównano z charakterystykami naturalnego kruszywa żwirowo-piaskowego – kruszywa naturalnego NA). Wyniki zebrane z badań CTS wskazują, że wydajność większości destruktu betonowego jest porównywalna z kruszywem naturalnym i może być stosowana jako niezwiązany materiał ziarnisty (UGM).

11

Analysis of synchronized asynchronous generator for a wind electric installation

Mammadov Nijat, Rzayeva Sona, Ganiyeva Nigar

Przegląd Elektrotechniczny

|

2023

|

R. 99, nr 5

37--40

EN

Objective. Analysis of the effectiveness of the use of SAG, excited according to a fundamentally new scheme, in a wind electric installation. This article analysis the application of the efficiency of a synchronized asynchronous generator in a wind electric installation. This is natural in vibration damping, which causes gusts of wind and changes in wind speed, as well as an increase in the efficiency of the device at low wind speeds. The article shows a schematic diagram of a synchronized asynchronous generator of a wind electric installation. Some properties of the synchronized asynchronous generator that drives the circuit are also explored. The article presents the advantages of using a synchronized asynchronous generator for wind turbines. The results of calculated characteristics for the given system of values are given. The possibility of operation at cosφ =1 is considered.

PL

Cel. Analiza efektywności wykorzystania SAG, wzbudzonego według zasadniczo nowego schematu, w wiatrowej instalacji elektrycznej. W artykule dokonano analizy zastosowania sprawności zsynchronizowanego generatora asynchronicznego w elektrowni wiatrowej. Jest to naturalne przy tłumieniu drgań, które powoduje podmuchy wiatru i zmiany prędkości wiatru oraz wzrost wydajności urządzenia przy małych prędkościach wiatru. W artykule przedstawiono schemat ideowy zsynchronizowanego generatora asynchronicznego wiatrowej instalacji elektrycznej. Badane są również niektóre właściwości zsynchronizowanego generatora asynchronicznego, który napędza obwód. W artykule przedstawiono zalety zastosowania zsynchronizowanego generatora asynchronicznego do turbin wiatrowych. Podano wyniki obliczonych charakterystyk dla zadanego systemu wartości. Rozważana jest możliwość pracy przy cosφ =1.

12

Analysis of dynamic characteristics of a sealed ends squeeze film damper considering the fluid inertia force

Zhou Hai Lun, Cang Yang Guang, Zhang Yu Qi, Guo Chao

Journal of Theoretical and Applied Mechanics

|

2023

|

Vol. 61 nr 3

441--452

EN

In order to effectively calculate dynamic characteristics of a sealed ends squeeze film damper (SFD) under the influence of the inertial force, a computational fluid dynamics model of the sealed ends SFD is established. The fluid inertia coefficient of SFD is investigated by using an energy approximation method. Both the theoretical calculation and numerical simulation are conducted to analyze the effects of eccentricity ratio and whirling frequency on stiffness and damping. In this research, the oil film inertia force of the sealed ends SFD is solved by using long bearing approximation (LBA) theory, which provides guidance for the design and application of the sealed ends SFD.

13

A certain class of fractional difference equations with damping: Oscillatory properties

Arundhathi Sivakumar, Alzabut Jehad, Muthulakshmi Velu, Adıgüzel Hakan

Demonstratio Mathematica

|

2023

|

Vol. 56, nr 1

art. no. 20220236

EN

In this study, we have investigated the oscillatory properties of the following fractional difference equation: [formula] where […] denotes the Liouville fractional difference operator of order α ∈ (0,1), p , and q are nonnegative sequences, and г and G are real valued continuous functions, all of which satisfy certain assumptions. Using the generalized Riccati transformation technique, mathematical inequalities, and comparison results, we have found a number of new oscillation results. A few examples have been built up in this context to illustrate the main findings. The conclusion of this study is regarded as an expansion of continuous time to discrete time in fractional contexts.

14

Some recent developments in inerter-based devices for vibration mitigation

Wagg David J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 3

art. no. e144617

EN

Reducing the effect of unwanted vibrations is an important topic in many engineering applications. In this paper we describe some recent developments in the area of passive vibration mitigation. This is based on a new device called the inerter which can be exploited in a range of different contexts. In this paper we consider two recent examples; (i) where a flywheel inerter is combined with a hysteretic damper, and (ii) in which a pivoted bar inerter is developed for a machining application. In both cases, experimental test results show that the devices can outperform existing methods.

15

Influence of material distribution and damping on the dynamic stability of Bernoulli-Euler beams

Garus Sebastian, Garus Justyna, Sochacki Wojciech, Nabiałek Marcin, Petru Jana, Borek Wojciech, Šofer Michal, Kwiatoń Paweł

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 4

art. no. e145567

EN

The study analyzed the influence of materials and different types of damping on the dynamic stability of the Bernoulli-Euler beam. Using the mode summation method and applying an orthogonal condition of eigenfunctions and describing the analyzed system with the Mathieu equation, the problem of dynamic stability was solved. By examining the influence of internal and external damping and damping in the beam supports, their influence on the regions of stability and instability of the solution to the Mathieu equation was determined.

16

Analysis of Flow-Induced Vibrations in a Heat Exchanger Tube Bundle Subjected to Variable Tube Flow Velocity

Hafeez Akmal, Khushnood Shahab, Nizam Luqman Ahmad, Usman Muhammad, Rashid Muhammad Mohsin, Khan Hassan Farid, Ayub Muhammad, Qadir Adeel

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 2

279--288

EN

Tube bundles of shell and tube-type heat exchangers often fail because of vibrations produced in tubes due to flow. The turbulence in the flow is the primary cause of vibrations in the tubes. In this study, a tube positioned in the third row of the tube bundle was considered to determine the vibrational response of the heat exchanger tubes. The tube bundle was parallelly arranged in a triangular (60°) configuration having a pitch to diameter (P/D) ratio of 1.44. The internal tube flow velocity ranges from 0 to 0.371 m/s and the shell side velocity ranges from 0.5 m/s to 2 m/s. The experimentation shows that the amplitude of vibration without flow inside the tube is less as compared to the amplitude with the flow. Furthermore, as the velocity of internal tube flow escalates; the amplitude of tube vibrations tends to escalate as well even when the shell side flow velocity is kept constant. The data points from experiments tend to reside in the unstable region of the stability map and particularly on the map’s left side, although the tube shows stable vibration behaviour as confirmed by the experimental results. Thus, further, development can be done by modifying the theoretical models to predict the realistic stability behaviour of tubes with internal tube flow.

17

Studying the dynamic system “tire-suspension-body” by the resonance method

Gogiashvili Phridon, Kbilashvili David, Chogovadze Jumber, Lekveishvili Gocha, Sirbiladze Besik

Transport Problems

|

2022

|

T. 17, z. 1

63--72

EN

By comparing the results of a pilot study of the damping coefficient of a pneumatic tire carried out on a test bench, this study justifies the possibility of using the less time-consuming experimental resonance curve method instead of the dynamic loop method. A mathematical model of the vertical oscillations of a vehicle’s dynamic system “pneumatic wheel-suspension-sprung weight”was created on the test-bench, and an image of the amplitude-frequency characteristic of the sprung weight oscillation was obtained. The approaches and results of the pilot and analytical studies presented in the article aid the selection of the tire with the best damping properties. The use of the experimental resonance curve method to determine the damping characteristic of a vehicle’s tire is limited in the external frequency range of the resonant frequencies. In this case, we have to use the dynamic loop method.

18

Vibration analysis of a turning tool with passive damping

Klamczyński Kamil

Mechanik

|

2022

|

R. 95, nr 10

40--46

EN

Mechanical vibrations generated during machining can cause many problems in production processes. Vibrations can cause high dynamic loads leading to damage of the machine spindle, the cutting tool or the workpiece. Another unwanted effect of the existence of vibration during the machining process can be a deterioration in the quality of the machined surface. In this paper, a comparative analysis was carried out based on studies of the face turning process with conventional knives and those equipped with passive vibration damping systems. The results show the influence of the implemented vibration damper on the cutting process.

PL

Drgania mechaniczne pojawiające się podczas obróbki skrawaniem mogą być przyczyną występowania wielu problemów w procesach produkcyjnych. Drgania mogą powodować duże obciążenia dynamiczne prowadzące do uszkodzenia wrzeciona obrabiarki, narzędzia skrawającego lub przedmiotu obrabianego. Innym niepożądanym efektem występowania drgań w czasie procesu obróbki mechanicznej może być pogorszenie jakości obrabianej powierzchni. W niniejszej pracy przeprowadzono analizę porównawczą na podstawie badań procesu toczenia czołowego powierzchni nożami konwencjonalnymi i wyposażonymi w pasywne systemy tłumienia drgań. Wyniki badań przedstawiają wpływ zastosowanego tłumika drgań na przebieg procesu skrawania.

19

Insight into Damping Sources in Turbines

Moneta Grzegorz

Fatigue of Aircraft Structures

|

2022

|

Iss. 14

69--82

EN

Blade vibrations in aircraft engines are a significant challenge that must be overcome during the design and development of modern turbine engines. Vibrations lead to cyclic displacements and result in alternating stress and strain in undesired environments (high temperatures, erosion, corrosion of the surface, etc.). Under resonance conditions, stress amplitudes can increase and exceed their safety limits, and in extreme cases, can lead to engine failure. One method to reduce resonance vibrations is to increase damping in the turbine assembly. This paper presents and describes vibration damping sources in the turbine, including aerodynamic, material, and friction damping. Additionally, typical damping values for each damping component are presented and compared.

20

Seismic codes based equivalent nonlinear and stochastic soil structure interaction analysis

Guellil Mohamed Elhebib, Harichane Zamila, Çelebi Erkan

Studia Geotechnica et Mechanica

|

2021

|

Vol. 43, nr 1

1--14

EN

The aim of this study is to consider the effects of the variation of shear modulus ratio (G/G0) and damping ratio (ξ) of soil, obtained by a linear iterative method based on the design spectra of seismic codes, the soil environment in terms of uncertainties in shear modulus using Monte Carlo simulations and the foundation damping (ξf) of flexible base for analyses of the Soil-Structure Interaction (SSI) problems. A squat structure with circular shallow foundation resting on a soil layer over a homogeneous half-space is studied by using cone model and considering seismic zone effect on structural response. Firstly, after showing the effects of the correction of G and ξ on impedance functions and the responses of soil-foundation-structure system, a study is carried out to compare these effects to those of the modelling of uncertainties in shear modulus as random variations. Secondly, a comparative analysis on design response spectra and base shear forces was carried out for four seismic codes (Algerian Seismic Rules RPA99- 2003, Eurocode 8-2004, International Building Code IBC-2015 and Indian Code IS-1893-2002) considering the three cases of SSI: SSI effects (initial G and ξ), nonlinear SSI (corrected G and ξ) and stochastic SSI (random G with COV = 20%) compared to the fixed base case. Results show that the correction of G and ξ, according to the equivalent nonlinear method in all the cases, leads to a remarkable decrease in peak responses but show a huge amount of reduction in the second study for IBC-2015 and IS-1893-2002 codes compared to the other codes.