Wyniki wyszukiwania - BazTech

1

Assessment of the technical state of mining machinery and devices with the use of diagnostic methods

Biały Witold

Production Engineering Archives

|

2024

|

Vol. 30, Iss. 2

266--272

EN

In this article, one of the possible, effective methods of assessing the technical state of mining machinery and devices has been presented. The article's main goal is to show the possible methods and ways of measuring temperature, oscillations, and vibrations generated during the operation of mining equipment and machines’ gears, which are possible in underground conditions. Devices measuring temperatures without coming into contact with the given object are built based on different types of infrared radiation detectors or matrixes of such detectors. Thermal imaging devices picture the temperature distribution on the entire surface instead of pyrometers, which measure temperatures at a given point. However, vibrations and oscillations generated by the work of gears of devices and machinery have been made using a vibrometer pen and a machine condition tester, after which the obtained measurements were used to diagnose the degradation of individual elements of those machines. Such an assessment of the degradation of individual elements of machines in production conditions has been applied with positive results in one of the mines of the Polish Mining Group (Polska Grupa Górnicza – PGG).

2

Ograniczanie drgań układu wentylator-silnik elektryczny na przykładzie remontowanej instalacji wentylacyjnej - studium przypadku

Walaszczyk Juliusz

Instal

|

2024

|

nr 2

36--43

PL

W ostatnich latach coraz mniej uwagi przykłada się do elementów związanych z prawidłową amortyzacją maszyn wirnikowych (wentylator - silnik, pompa - silnik itd.). W pogoni za ograniczeniami, przede wszystkim kosztów inwestycyjnych, nierzadko podejmowane są pochopne decyzje związane z „odchudzaniem” ram podporowych czy fundamentów pod maszyny wirnikowe. Dla zobrazowania skutków takich działań w artykule przedstawiono i omówiono wyniki pomiarów drgań wykonanych w obiekcie rzeczywistym przed oraz po wymianie instalacji wentylacyjnej obsługującej halę przemysłową. Wyniki pomiarów zestawiono z wynikami obliczeń wykonanych na podstawie 3 metod teoretycznych. Wykazano, że odpowiednia masa ramy podporowej oraz staranne wypoziomowanie układów mają decydujący wpływ na uzyskiwane amplitudy drgań. Tezę tę udowodniono poprzez ograniczenie drgań z 16,39 mm/s RMS do 4,23 mm/s RMS. Wykazano, że regularne monitorowanie amortyzacji może skutecznie i szybko doprowadzić do wykrycia problemów związanych z pracą wentylatorów i silników (uszkodzenie łożysk, niebezpieczne amplitudy drgań przegród budowlanych).

EN

In recent years, less and less attention has been paid to elements related to the proper depreciation of rotating machines (fan - electric motor, pump - electric motor, etc.). In the pursuit of reductions, especially in investment costs, hasty decisions are often made related to “slimming” support frames or foundations for rotating machines. To illustrate the effects of such actions, the article presents and discusses the results of vibration measurements performed in a real facility before and after replacing the ventilation installation that serves an industrial hall. The measurement results were compared with the results of calculations made based on 3 theoretical methods. It has been shown that the appropriate mass of the support frame and careful levelling of the systems have a decisive impact on the vibration amplitudes obtained. This thesis was proven by reducing vibrations from 16.39 mm/s RMS to 4.23 mm/s RMS. It has been shown that by regular monitoring of isolators depreciation one can effectively and quickly detect problems related to the operation of fans and electric motors (damage to bearings, dangerous vibration amplitudes of building partitions).

3

Investigation of The Effect of Mechanical Vibration Applied During Solidification on The Microstructure and Properties of Aluminum 356 Alloy

Özgü Taha Süreyya, Çalın Recept, Tanış Naci Arda

Archives of Foundry Engineering

|

2024

|

Vol. 24, iss. 1

26--31

EN

Manufacturing by casting method in aluminum and its alloys is preferred by different industries today. It may be necessary to improve the mechanical properties of the materials according to different industries and different strength requirements. The mechanical properties of metal alloys are directly related to the microstructure grain sizes. Therefore, many grain reduction methods are used during production or heat treatment. In this study, A356 alloys were molded into molds at 750°C and exposed to vibration frequency at 0,8.33, 16.66, 25, and 33.33 Hz during solidification. Optical microscopes images were analyzed in image analysis programs to measure the grain sizes of the samples that solidified after solidification. In addition, microhardness tests of samples were carried out to examine the effect of vibration and grain reduction on mechanical behavior. In the analyzes made, it was determined that the grain sizes decreased from 54.984 to 26.958 μm and the hardness values increased from 60.48 to 126.94 HV with increasing vibration frequency.

4

Operation of a new single-vibrator conveyor on the falling slope of the second resonance

Żmuda Weronika, Czubak Piotr

Transport Problems

|

2023

|

T. 18, z. 4

223--232

EN

The paper presents the possibilities of operating an innovative single- vibrator-driven vibratory conveyor [1] in the vicinity of the second resonance zone. The characteristics of operation on both ascending and descending slopes are presented. The differences in the suspension deflection of the additional mass (which is a dynamic eliminator) during operation before and after the resonance were analyzed. We proposed working on the descending slope of the second resonance in order to increase the durability of the device. This is because the amplitude of the suspension deflection of the additional mass is limited and, due to its high stiffness, is exposed to material fatigue. This is an unusual method of operation for conveyors because it carries certain risks, such as the risk of the device entering resonance on its own or the problem of maintaining constant angular velocity of the unbalanced masses. This paper presents both analytical and simulation studies, which were then confirmed on a laboratory stand designed and built by the authors.

5

Evaluation of vibration and noise characteristics of a compression-ignition engine fuelled with natural gas-biodiesel dual fuel

Stravinskas Saulius, Rimkus Alfredas, Matijošius Jonas

Transport Problems

|

2023

|

T. 18, z. 1

67--74

EN

As environmental requirements become more stringent and the planet becomes more polluted, the replacement of conventional diesel is attracting more interest. For alternative fuels, such as biodiesel and natural gas, to be used, their effects must be examined not only in terms of the engine’s environmental indicators but also in terms of engine vibrations and sound pressure. This study examined the influence of dual fuel – biodiesel and natural gas – on vibrations and sound pressure of a compression-ignition (CI) engine. Conventional diesel or hydrotreated vegetable oil biodiesel was used as a pilot fuel for gas ignition. The gaseous fuel was natural gas, which was injected into the intake manifold with different energy shares of the gaseous fuel (40%, 60% and 80%). Tests were performed at a constant engine crankshaft speed and a fixed start of pilot fuel injection of 6° BTDC while the fuel composition and engine load were changed. This experiment revealed correlations between gas energy share (GES) in liquid fuel and ecological and energy indicators of a CI engine.

6

Noise emission and vibration study of a mista rd-165 fhad grader to reduce environmental harmful impact

Kobiałka Janusz, Barszcz Andrzej

Technologia i Automatyzacja Montażu

|

2023

|

nr 2

50--55

EN

Construction machinery noise emission and vibration on the operator site are the most important harmful factors having impact on human health. They affect for people working on the operators and as well as other persons around the machine. The article concerns the issues of noise level and noise emission measurements applied to the earthmoving machinery which are covered by the EU directive 2005/88/EC. The methods of noise testing during design and in the certification, process has been described. The basic information about testing the noise emission to the environment has been presented. Methods and results of vibration tests affecting the operator are also presented. The reference documents and EU standards concerning this topics have been described. The noise testing methods has been presented based on the prototyping and R&D cycle of the Mista RD-165 FHAD grader which is subjected to the European noise limits. The results of noise measurements and sound power level determination has been presented. The testing procedure implemented during two stages of R&D cycle. The article describes the effects of the improvements in the grader focused on noise emission limitation limits.

PL

Hałas emitowany przez maszyny budowlane jest jednym z głównych czynników szkodliwych wpływających na środowisko, a szczególnie na zdrowie osób przebywających w obszarze oddziaływania tych maszyn. Narażonym na hałas poddane są osoby bezpośrednio zaangażowane w pracę, ale również inne osoby znajdujące się w otoczeniu maszyny. Artykuł porusza zagadnienia badania hałasu i drgań miejscowych w maszynach budowlanych podlegających pod dyrektywę Unii Europejskiej 2005/88/WE. Omówione zostały sposoby badania hałasu w trakcie produkcji i certyfikacji maszyn. Przedstawiono podstawowe informacje dotyczące przeprowadzania badań emisji hałasu do otoczenia. Przywołano dokumenty odniesienia i normy badawcze które regulują te badania. Na przykładzie równiarki drogowej Mista RD-165 FHAD, która podlega limitom emisji hałasu, przedstawiono prowadzenie badań podczas prac badawczo-rozwojowych. Przedstawione zostały wyniki pomiarów hałasu i wyznaczona moc akustyczna maszyny. Badania były wykonywane na dwóch etapach prac konstrukcyjnych. W artykule zaprezentowano efekty prac doskonalących konstrukcję pod względem zmniejszenia emisji hałasu do otoczenia.

7

Operating characteristics of bearings with magnetic nanoparticles doped lubricant

Krenicky Tibor, Mascenik Jozef, Coranic Tomas, Ruzbarsky Juraj

Mining Machines

|

2023

|

vol. 41, iss. 3

168--174

EN

The main aim of the presented research was to investigate theoperational characteristics of a bearing when alternative lubricants were used for comparison with a standard lubricant, including that containing magnetic nanoparticles. The bearing was subjected to varying operating conditions, differing in terms of mechanical load status. The monitoring of the bearing operation parameters primarily focused on monitoring the velocity and acceleration of vibrations, as well as the operating temperature of the bearing. Thebearingwith lubricant doped by magnetic nanoparticles exhibited reduced vibration velocity and acceleration values both under no load conditions and when subjected to a mechanicalload. The operating temperature slightly increased during testing in the case ofthe bearing with nanoparticles compared to the bearing using the original lubricant.

8

Analysis of the influence of adding rubber recyclate on the strength properties of epoxy-glass composites

Abramczyk Norbert, Żuk Daria, Panasiuk Katarzyna

Journal of KONBiN

|

2023

|

Vol. 53, iss. 1

1--24

EN

The article attempts to assess the possibility of using rubber recyclate as a component of composite materials. Research is being carried out to develop a technology for the production of composite materials with the addition of rubber waste. These tests are aimed at increasing the reliability and safety of the operation of structures exposed to longterm impact of devices generating vibrations. At the same time, work is underway on the use of complex composite surfaces as sound-absorbing elements. The new direction of using recyclates will have a positive impact on the management of environmentally harmful waste, taking into account a favorable economic factor.

PL

W artykule podjęto próbę oceny możliwości wykorzystania recyklatu gumowego jako składnika materiałów kompozytowych. Prowadzone są badania mające na celu opracowanie technologii wytwarzania materiałów kompozytowych z dodatkiem odpadu gumowego. Badania te są ukierunkowane na zwiększenie niezawodności i bezpieczeństwa obsługi konstrukcji narażonych na długotrwałe oddziaływanie urządzeń generujących wibracje. Jednocześnie trwają prace nad wykorzystaniem złożonych powierzchni kompozytowych jako elementów dźwiękochłonnych. Nowy kierunek wykorzystania recyklatów będzie miał korzystny wpływ na zagospodarowanie szkodliwych dla środowiska odpadów z uwzględnieniem korzystnego czynnika ekonomicznego.

9

Influence of the specific load on stability and vibrations of the multimember column with internal cracks

Sokół Krzysztof, Kuliński Krzysztof

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 4

art. no. e146408

EN

Slender systems are mostly studied when Euler’s load or follower load is considered. The use of those types of external loads results in well-known divergence or flutter shape of the characteristic curve. In this study, one takes into account the specific load which allows one to obtain an interesting divergence – pseudo flutter shape of characteristic curves on the external load–vibration frequency plane. The curves can change inclination angle as well as one can observe the change in vibration modes along them. The shape of those curves depends not only on the parameters of the slender system but also on loading heads that induce the specific load. In this study, one considers the slender multimember system in which cracks are present and weaken the host structure. The results of theoretical as well as numerical simulations are focused on the influence of the parameters of the loading heads on vibrations, stability, and loading capacity of the investigated system as well as on the possibility of partial reduction of unwanted crack effect.

10

Forecasting the Natural Frequency of the Brake Disccasting

Zyska Andrzej, Bieroński Mariusz

Archives of Foundry Engineering

|

2023

|

Vol. 23, iss. 4

87--92

EN

The paper presents the results of calculations and measurements of the first natural frequency of castings of solid and ventilated brake discs made of gray cast iron of the EN-GJL-200 class. The tests were carried out for three types of chemical composition, taking into account the permissible minimum and maximum content of alloying elements. Numerical simulations of natural vibrations were carried out on the basis of our own production material databases. To determine the elastic properties of cast iron, the ultrasonic method with the measurement of the propagation velocity of longitudinal and transverse waves was used. Measurements were made directly on casts of raw discs of various thicknesses. The values of Young's modulus and Poisson's number calculated from ultrasonic measurements were used to define the stiffness matrix in the equilibrium equation, which is solved by the solver of the MSC Nastran program. A high compatibility between the results of numerical simulations and the results of experimental FRF frequency analysis was obtained. The differences between the calculated and actual values were at the level of several hertz, while the estimated average error of numerical simulations was 0.76%. It was also found out that cast iron melts for brake discs must be subject to strict control in terms of chemical composition. Slight deviations of the eutectic saturation coefficient from the optimal value cause a significant change in the first natural frequency of the brake discs, regardless of their geometry.

11

Vibration analysis of an Airlie beach house: a case study in Australia

Wheatley Greg, Babamiri Arash, Philippa Bronson

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2022

|

z. 114

179--192

EN

Airlie beach houses are quite common in the coastal areas of Australia. These houses, similar to other buildings, provide comfort for their residents. House comfort is not limited to temperature or sound pollution, vibration can be considered as another equally important factor. In this article, the vibration of an Airlie beach house was investigated. The base steel structure was modeled in SolidWorks and Space Gass for evaluating stress distribution and nodal displacement, respectively. To find the root cause of the distressing vibration of the house, which was felt with dwellings, the axial acceleration of the house’s structure was determined. Some feasible solutions such as adding a fiber-reinforced polymer joist hanger, inserting additional rubber padding to the joist hanger, and attaching additional bracing, were discussed and a cost analysis was considered for the solutions. Eventually, the nature of the best solution, which was adding rubber, was tested experimentally.

12

Transport features of a new, self-attuned conveyor

Czubak Piotr, Surówka Witold

Transport Problems

|

2022

|

T. 17, z. 4

5--16

EN

The new vibratory conveyor destined for the accurate dosing of materials was investigated in the present work. The possibilities of the system to transport materials in the circum-resonant zone were tested analytically, as well as by simulations. The optimal work point of the system, which allowed a decrease in the amplitude of eliminator vibrations on its suspension due to operations on the resonance slope, was determined. Transport velocities depending on the excitation frequency and feed mass were determined by simulations. The results were verified on the conveyor of industrial dimensions designed and built in accordance with the patent application.

13

Technologies and intelligent systems for adaptive vibration control in rail transport

Aliev Telman, Babayev Tofig, Musaeva Naila, Mammadova Ana, Alibayli Elnur

Transport Problems

|

2022

|

T. 17, z. 3

31--38

EN

Vibration diagnostics is of particular importance in rail transport safety systems because the signals received from vibration sensors installed on rolling stock, bridges, tunnels, and other infrastructure objects have great diagnostic information potential. Despite this, in practice, there are cases when the adequacy of the results of the vibration control and diagnostics task is not ensured. The reason is that the sampling step of the vibration signal does not change when the train speed changes. Given the need to change the sampling interval depending on the train speed, this article proposes an adaptive technology for vibration signal sampling that allows the building of intelligent systems of adaptive vibration control of malfunctions in rail transport.

14

Investigations of the transport possibilities of a new vibratory conveyor equipped with a single electrovibrator

Żmuda Weronika, Czubak Piotr

Transport Problems

|

2022

|

T. 17, z. 4

127--136

EN

In the present study, a new vibratory conveyor (patent pending) equipped with a single electro-vibrator intended for an accurate material dosage is investigated. The possibilities of material transportation in the circum-resonant zone were investigated analytically and by simulations [1]. Furthermore, the dependencies of the transport velocity of the tested conveyor as functions of the excitation frequency were determined. Favorable excitation frequencies at transports in the main and reversal directions were found, and the high usefulness of the machine in the production lines requiring accurate material dosage was indicated. A control strategy allowing for a sudden stop of the transported material was also proposed.

15

Measurement of dynamic characteristics of screw conveyor

Coranič Tomáš, Maščeník Jozef, Ružbarský Juraj, Krenický Tibor

Systemy Wspomagania w Inżynierii Produkcji

|

2022

|

Vol. 11, iss. 2

66--76

EN

A machine has always been, is and will be the technical progress. The basis of every economy is the progressiveness of manufacturing engineering since it manufactures components for all industries. Technical requirements in manufacturing engineering are constantly leading to an increase of the technical level of manufacturing equipment. Profound knowledge of scientific fields precedes a successful fulfilment of the technical requirements. Structural units of manufacturing machines are complex mechanisms that must work reliably and safely with an emphasis on their important function. These units create new objectives for their research and optimization.

16

The problem and analysis of vibrations appearing in N10 and N11 groups military vehicles with manually-operated armament modules

Dorczuk Maciej, Wachowiak Przemysław

Scientific Journal of the Military University of Land Forces

|

2022

|

Vol. 54, No. 1(203)

5--20

EN

This article is a continuation of work aimed to identify vibrations. It contains the results of tests, calculations, and analyses in the field of vibrations occurring on the elements of equipment of the N10 group tracked vehicle and the N11 group armored wheeled vehicle (classification according to NO-06-A103:2005) equipped with manually operated weapon systems. A detailed description of the analyses carried out, and the results of the research on the N10 group vehicle are contained in the article: "The Problem and Analysis of Vibrations Appearing in an N10 Group Military Vehicle Fitted with a Manually-Operated Armament Module" published in the quarterly Problems of Mechatronics Armament, Aviation, Safety Engineering. This study thoroughly presents the test results and their analysis for the N11 group vehicle and only recalls the results of similar tests and analyses for the N10 group vehicle for comparison. The research aimed to get acquainted with the characteristics of vibrations occurring in stabilized turret systems (weapon system) and devices supplying turret systems in terms of amplitudes, practical values, and their energy for various operating conditions. The analyses were carried out concerning the requirements of the Polish defense standard NO-06-A103:2005 and MIL-STD-810F regarding the correctness of their application.

PL

Artykuł to kontynuacja prac, celem których jest poznanie rzeczywistych wibracji. Zawiera wyniki przeprowadzonych badań, obliczeń i analiz w zakresie wibracji występujących na elementach wyposażenia pojazdu gąsienicowego z grupy N10 oraz opancerzonego pojazdu kołowego z grupy N11 (klasyfikacje wg NO-06-A103:2005) wyposażonych w ręcznie sterowane systemy uzbrojenia. Szczegółowy opis przeprowadzonych analiz oraz wyniki badań w zakresie pojazdu grupy N10 zawarte są w artykule: „The Problem and Analysis of Vibrations Appearing in an N10 Group Military Vehicle Fitted with a Manually-Operated Armament Module” opublikowanym w kwartalniku Problems of Mechatronics Armament, Aviation, Safety Engineering. Niniejszy artykuł gruntownie prezentuje wyniki badań oraz ich analizy dla pojazdu grupy N11 i przywołuje jedynie wyniki analogicznych badań i analiz dla pojazdu grupy N10 w celu ich porównania. Przeprowadzone badania miały na celu zapoznanie się z charakterystyką drgań występujących na stabilizowanych systemach wieżowych (systemie uzbrojenia) oraz urządzeniach zasilających systemy wieżowe w aspekcie amplitud, wartości skutecznych oraz ich energii dla różnych warunków eksploatacji. Analizy przeprowadzono w odniesieniu do wymagań polskiej normy obronnej NO-06-A103:2005 oraz MIL-STD-810F w aspekcie słuszności ich stosowania.

17

Możliwość wykorzystania SEM maszyny ze wzbudzeniem od magnesów trwałych do diagnostyki wibracyjnej

Barański Marcin

Napędy i Sterowanie

|

2022

|

R. 24, nr 5

32, 34--37

PL

W artykule zaprezentowano wyniki badań pokazujące możliwość wykorzystania SEM maszyn z magnesami trwałymi do diagnostyki wibracyjnej. Przedstawiono właściwość polegającą na indukowaniu się składowej periodycznej SEM pod wpływem czynników zewnętrznych, np. drgań. Opisano wyniki testów przeprowadzonych na stole wibracyjnym. Przedstawiono przebiegi czasowe prędkości drgań, napięć indukowanych wraz z analizą częstotliwościową - zarówno dla maszyny będącej w spoczynku, jak również napędzanej. Przedstawiono częstotliwości odpowiadające konkretnym stanom niepożądanym w maszynie PM, które udało się do tej pory wyselekcjonować autorowi.

EN

The results of research which demonstrate the possibility of using SEM of machines with permanent magnets for vibration diagnostics. Specific structural properties of PM machines are used by this method - electromotive force (EMF) generated due to vibrations. The results of tests which were made with use of vibration table was described. The wave-forms of vibration velocity, induced voltages and frequency analysis are presented - for both states: machine was at rested and driven. Frequencies corresponding to specific undesirable conditions accruing in the PM machine, which the author has been able to select so far, are presented.

18

A Quick-and-Dirty Method for assessing the Risk of Negative Aeration Effects of Shock Absorbers equipped with Shim Sliding Base Valves

Czop Piotr, Gniłka Jacek

Computer Assisted Methods in Engineering and Science

|

2022

|

Vol. 29, no. 3

229--260

EN

This paper presents a quick-and-dirty method to assess the risk of negative aeration effects occurring in twin-tube hydraulic shock absorbers used in passenger cars at the early design stage. The method is intended to be implemented as an engineering calculation tool based on the computational fluid dynamics (CFD) two-dimensional (2D)/three-dimensional (3D) steady-state single-phase model. The CFD model was previously validated with the use of the particle image velocimetry (PIV) experiment. The negative aeration effect is a wellknown issue for automotive and railway shock absorbers manufacturers. It results in uncontrolled on-vehicle vibrations and the deteriorated shock absorber damping characteristic. The major aeration contributor in twin-tube hydraulic shock absorbers is the sliding shim intake valve, which requires design optimization to avoid a negative aeration effect. The method validation was conducted with the customized test rig equipped with a transparent cylinder where the specific sliding intake valve was assembled. The proposed method also requires a lumped-parameter model of a twin-tube shock absorber, which allows to simulate boundary conditions in assessing particular reservoirs of a shock absorber, i.e., pressures and flow balance. The method is implemented as a calculation routine that converts CFD pressure regions into a gas concentration indicator (GCI) using the pressure-density characteristic of an oil-gas emulsion of a shock absorber. GCI is calculated based on the sum of particular 2D/3D grid elements. The method application is to minimize the risk of occurrence of negative aeration effects by avoiding expensive and time-consuming experimental tests. This method can also be used for in-production shock absorbers projects as a part of a continuous improvement cycle or in the case of inefficient shock absorbers claimed by a vehicle manufacturer. The application scope of the method can be extended for arbitrary twin-tube designs of shock absorbers in the automotive and railway industries.

19

Application of heuristic methods to identification of the parameters of discrete-continuous models

Cekus Dawid, Kwiatoń Paweł, Šofer Michal, Šofer Pavel

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2022

|

Vol. 70, nr 1

art. no. e140150

EN

The article presents the process of identifying discrete-continuous models with the use of heuristic algorithms. A stepped cantilever beam was used as an example of a discrete-continuous model. The theoretical model was developed based on the formalism of Lagrange multipliers and the Timoshenko theory. Based on experimental research, the theoretical model was validated and the optimization problem was formulated. Optimizations were made for two algorithms: genetic (GA) and particle swarm (PSO). The minimization of the relative error of the obtained experimental and numerical results was used as the objective function. The performed process of identifying the theoretical model can be used to determine the eigenfrequencies of models without the need to conduct experimental tests. The presented methodology regarding the parameter identification of the beams with the variable cross-sectional area (according to the Timosheno theory) with additional discrete components allows us to solve similar problems without the need to exit complex patterns.

20

Influence of the type of place occupied by a tram passenger on the ride comfort

Bakinowski Łukasz, Firlik Bartosz

Archives of Transport

|

2022

|

Vol. 62, iss. 2

49--58

EN

In cities with developed transport infrastructure, many people use public transport in their everyday lives. In order for the passenger's journey to be comfortable and for the passenger to travel more willingly by tram than by car, many conditions must be met. A passenger must feel comfortable in a public transport vehicle, which includes, among others: appropriate temperature in the vehicle, no crowding, the possibility to seat, the possibility of a quick vehicle-change, short travel time, no noise and many others. A very important criterion from the point of view of travel comfort is also the level of vibrations in the tram. A tendency can be noticed that vehicles with a low vibration level are rated much higher by public transport passengers and citizens. Vibration itself can also be an indirect cause of noise. The greater the noise, the greater the dissatisfaction of the passenger which indicates the high role of vibrations as a factor of passenger satisfaction or dissatisfaction. The aim of the work is to test and evaluate the vibration level in the partially low-floor Moderus Beta MF 02 AC tram manufactured by the company Modertrans Poznań in Poland. Assessed was be the vibration comfort in selected points of the vehicle, including the floor and passenger seat. The level of vibrations in trams of the same type were compared. Due to the lack of specific Polish regulations regarding the permissible level of vibration in trams, an attempt was made to compare the obtained results with railway standards requirements or foreign countries requirements. The study proved that the level of vibrations differs in trams belonging to the same type. Significant damping of vibrations in the vertical direction by the passenger seat was observed. Maximum level of vibrations in the passenger area of the vehicle was observed on the floor above the bogie. It was found when comparing the values of vibration accelerations and comfort indicators with railway standards - that the Moderus Beta tram on the reference section of the track could be considered as a very comfortable vehicle.