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Research Article

Experimental study and comparative analysis of pitting fault in spur gear system

By Kemajou Herbert Yakeu Happi, Bernard Xavier Tchomeni Kouejou, Alfayo Anyika Alugongo

This paper uses a dynamic six-degree-of-freedom model that considers torsional and lateral motions to predict the impact of pitting on vibration parameters in a spur gearbox for various operating speeds and torque loads. The study examines the dynamic characteristics of a gearbox with localized pitting damage on a single gear tooth using theoretical and experimental approaches. The research analyzes the forced vibrations of a single-stage spur gear system with pitting damage, which includes variations in mesh stiffness, damping, and gear error excitation, to identify symptoms of default. The equation of motion for the rotary gearbox system is established using the Lagrangian method in tandem with Short-Time Fourier Transform (STFT) and frequency-RPM map fault diagnosis. During real-time vibration monitoring, vibration signals are captured via accelerometers and processed in both the time and frequency domains using the LabVIEW data acquisition signal processing package to extract diagnostic information. The experimental findings demonstrate how vibration analysis combined with time-frequency processing can recognize machine conditions even in harsh operational conditions. Moreover, the experimental results indicate a significant similarity with the theoretical analysis and validate the effectiveness of the RPM frequency technique-based pitting detection method, which can be an asset in gear fault monitoring.

September 14, 2023

Vibration Engineering

Research Article

Research on the aerostatic rotary table for micro-gravity test based on micro-orifice throttling

This paper addresses the demand for high-precision micro-gravity simulation experiments on large spacecraft and presents the design of a single-axis aerostatic rotary table with a high load capacity and low disturbance torque. Firstly, the structure of the aerostatic rotary table is analyzed, and the physical and mathematical models of the aerostatic pressure thrust bearing are established. Computational fluid dynamics methods are then employed to investigate the impact of three different aperture throttle orifices on the bearing performance. Through extensive research on the flow field of the bearing air film, it is discovered that changes in the aperture of the throttle orifices directly influence the pressure distribution, turbulence intensity, and gas vortex generation, thereby affecting the performance and stability of the bearing. Based on the calculation results, a single-axis aerostatic rotary table with a throttle orifice diameter of 0.1 mm is manufactured, and tests are conducted to measure its disturbance torque and load capacity. The test results demonstrate that the disturbance torque of the aerostatic rotary table is less than 9.2×10-5 N·m, and the rated load capacity exceeds 1000 kg. Finally, the research findings offer a theoretical foundation and data support for the design and development of aerostatic rotary table with high load capacity and low disturbance torque. This advancement paves the way for a superior solution in conducting precise micro-gravity simulation tests on large spacecraft.

August 1, 2024

Industrial Engineering

Research Article

Torsional effect analysis of high-rise reinforced concrete space grid cassette multi-tube structure system

The manuscript introduces a new structural system called the reinforced concrete (RC) space grid cassette multi-tube structure for high-rise buildings. A case study building is analyzed using this system and compared to a conventional RC frame-core tube structure. Through modal analysis in the software “Midas Gen”, the torsional effect and control indices like inter-story displacement ratio, maximum displacement, etc. are compared between the two structural systems. The results show that the space grid cassette system has smaller displacement ratios, displacements, inter-story torsion angles, and thus better torsional resistance compared to the conventional frame-core tube system. Based on these analyses, the manuscript concludes that the RC space grid cassette multi-tube structural system has superior seismic performance and is more suitable for irregularly shaped high-rise residential buildings.

July 31, 2024

Vibration Engineering

Research Article

Prestressed concrete continuous bridge girders: comparison of the Chinese and Southern African codes

To provide a reference for designers, taking a 30 m + 40 m + 30 m prestressed concrete continuous beam bridge as an example, this paper compares the differences between Chinese Codes and Southern African Codes in terms of load effect, prestressing requirements and design safety. The results show that the actual number of prestressed strands required by the Southern African Code in the mid-span section is 11.63 %-12.50 % larger than that required by the Chinese Code. The actual number of prestressed strands required by the Southern African Code in the fulcrum section is 16.33 %-30.00 % lower than that required by the Chinese Code. The safety margin factor of the section designed by the Southern African Code is higher than that of the Chinese Code, and has a higher safety reserve.

July 31, 2024

Vibration Engineering

Research Article

Review of supercapacitor technology and applications

While the world population is increasing day by day, environmental problems are reaching a level that cannot be ignored. Environmentalist steps are being taken in many areas, and governments are resorting to sanctions. It aims to reduce fossil fuel use as an environmental step in the transportation industry. Increasing the use of electric vehicles will be significant progress in achieving this goal. Batteries are generally used to store energy in electric vehicles. However, besides the weight problem and insufficient power density of the batteries, they have disadvantages, such as being produced from environmentally harmful materials. In this context, new energy storage technologies are being researched. One of them is “supercapacitor” technology. This paper is a review article examining several aspects of supercapacitors.

July 31, 2024

Informatics

## Latest from engineering

Research Article

A special graph for the connected metric dimension of graphs

Given a connected graph G=(V, E), let d(x, y) represent the separation between x and y at its vertices. If each vertex in a collection B is uniquely identified by its vector of distances to the vertices in B, then that set of vertices resolves a graph G. A metric dimension of G is represented by dim(G) and is the smallest cardinality of a resolving set of G. If the subgraph B- induced by B is a nontrivial connected subgraph of G, then a resolving set B of G is connected. The metric dimension of G is the cardinality of the minimal resolving set, while the connected metric dimension of G is the cardinality of the smallest connected resolving set. The connected metric dimension of the knots graph, whitehead link graph and jewel graph are determined in this study. Finally, we derive the explicit formulas for the triangular book graph, quadrilateral book graph and crystal planar map.

July 31, 2024

Informatics

Research Article

A measurement method for zero-degree thermostat

Thermocouple thermometers are widely used in laboratories and industry, the ice-water mixture is usually used as cold end compensation for thermocouple thermometer measurement. However, the ice-water mixture has disadvantages, such as complex manufacturing process, short use time, and unstable internal temperature field. The zero-temperature thermostat can replace the traditional ice water mixture to provide a stable temperature field environment. However, there is no suitable measurement method that can evaluate the zero-degree thermostat to meet the measurement requirements of thermocouple thermometer. Therefore, comparative experiments on temperature deviation, volatility, axial temperature field uniformity, radial temperature field uniformity, and load characteristics of the ice-water mixture and the zero-temperature thermostat are evaluated. In addition, the uncertainty of the zero-temperature thermostat and the ice water mixture is also proposed. The results reveal that the measurement results of temperature deviation, volatility, axial temperature field uniformity and load characteristic of the zero-temperature thermostat is smaller than that of the ice water mixture. Meanwhile, the uncertainty results also reveal that the zero-temperature thermostat is more stable than the ice water mixture. This study provides a comprehensive method for evaluating the performance of zero temperature thermostats, which can be used to verify the accuracy of the instrument and ensures the reliability of the thermocouple thermometers measurement, and promotes the development of zero temperature thermostat in temperature measurement field.

June 22, 2024

Applied Physics

Research Article

Analytical determination of critical velocity and frequencies of beam with moving mass under different supporting conditions

For a moving mass-beam system, the critical velocity of the moving mass is a key parameter that relates to the vibration stability of the system. In fact, the critical velocity obtained by the commonly used assumed mode method (AMM) differs from the actual situation. In this study, an analytical procedure is introduced to determine the critical velocity and frequency of the moving mass-beam system. The influence of moving mass is considered in the modal functions of the beam, and the frequency equations of the system were obtained through the modal analysis method and Laplace transform. And beams with four types of boundary condition were analyzed, which are hinged-hinged (HH) beam, clamped-hinged (CH) beam, clamped-clamped (CC) beam, and cantilever (CF) beam. By solving the frequency equations, the vibration frequencies of the system can be obtained, and the critical velocity can be determined. The results of the proposed method were validated by the finite element method (FEM). Through some examples, it was found that the natural frequency and critical velocity obtained by AMM is relatively high. And the critical velocities of the same moving mass-beam system under different supporting conditions ranked in ascending order are as follows: vcrHH<vcrCH<vcrCF<vcrCC. It is also found that when the moving mass undergoes variable motion on a beam, the vibration frequency obtained with acceleration considered is higher than that obtained with acceleration neglected. The results of this article will be helpful for structural design and its dynamic analysis.

June 22, 2024

Vibration Engineering

Research Article

A neural network simulator for educational purposes

Artificial neural networks are inspired by biologic processes. Artificial neural networks are important because they can be used to deduct a function from observations, in other words artificial neural networks can learn from experience. Artificial neural network simulator to fulfill a need into the growing interest of neural network education is introduced in this study. NeuroQuick Laboratory simulator is implemented using object-oriented programming by Delphi programming and these classes can be used to create a standalone application with artificial neural networks. The NeuroQuick Laboratory Simulator is designed for a broad range of users, including beginning graduate/advanced undergraduate students, engineers, and scientists. It is particularly well-suited for use in individual student projects or as a simulation tool in one- or two-semester neural network-related courses at universities.

June 6, 2024

Industrial Engineering

Recently published

Research article

May 23, 2024

Determinated area (DA) treatment goal when treating malocclusions with jaw functional orthopedics (JFO): Contribution to scientific evidence

By Eduardo Sakai, Luciano Wagner Ribeiro, Orlando Santiago Jr, Sergio Polizio Terçarolli, Jordanna Guedes Amorim

Recently published

Research article

May 23, 2024

Life prediction method of rolling bearing based on CNN-LSTM-AM

By Wanqing Huang, Yang Chen, Yongqi Chen, Tao Zhang

71st International Conference on VIBROENGINEERING

Major Conference Topic: Vibration & Condition Monitoring Problems

Date

December 12-13, 2024

Submission deadline

November 4, 2024

Conference format

Hybrid

## Best of engineering

Editor's pick

Research article

April 21, 2024

Research on citrus segmentation algorithm based on complex environment

By Jia Jun Zhang, Peng Chao Zhang, Jun Lin Huang, Kai Yue, Zhi Miao Guo

Editor's pick

Research article

April 14, 2024

Methods of detection and localization of the sources of noise and vibration on car gearboxes: a review

By Samnang Sann, Elias Tomeh, Tomas Petr

Editor's pick

Research article

April 4, 2024

Analysis of regulative documents in the field of human vibration safety

By Tsygankov Sergey, Abdreshov Shamil, Imangaliyeva Aizhan, Bimagambetova Lalita, Kurmashev Baurzhan, Torgayev Abish

Editor's pick

Research article

March 2, 2024

A simple harmonic quantum oscillator: fractionalization and solution

By Iqbal M. Batiha, Iqbal H. Jebril, Abeer A. Al-Nana, Shameseddin Alshorm

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Most downloaded

Research Article

A conversion guide: solar irradiance and lux illuminance

By Peter R. Michael, Danvers E. Johnston, Wilfrido Moreno

The standard for measuring solar irradiance utilizes the units of watts per meter squared (W/m2). Irradiance meters are both costly and limited in the ability to measure low irradiance values. With a lower cost and higher sensitivity in low light conditions, light meters measure luminous flux per unit area (illuminance) utilizing the units of lumens per meter squared or lux (lx). An effective conversion factor between W/m2 and lx would enable the use of light meters to evaluate photovoltaic performance under low solar irradiance conditions. A survey of the literature found no definitive and readily available “rule of thumb” conversion standard between solar irradiance and illuminance. Easy-to-find Internet sources contain conflicting and widely varying values ranging from 688449 to 21000 lx for 1000 W/m2 (1 Sun) of solar irradiance. Peer-reviewed literature contains Luminous Efficacy equivalent values ranging from 21 to 131 lx per W/m2. This manuscript explores the relationship and establishes a theoretical and laboratory measurement guide for the conversion between solar irradiance and illuminance. The conversion factor includes standards data, equipment calibration accuracy, and uncertainty estimates. Solar Irradiance of 1 Sun (1000 W/m2) for an LED-based solar simulator is (116 ± 3) klx and (122 ± 1) klx for outdoor sunlight.

December 4, 2020

Applied Physics

Most downloaded

Research Article

Design and calculation of double arm suspension of a car

By David Jebaraj B, Sharath Prasanna R

Suspension system is one of the challenging portions in designing a vehicle. The complete stability of the vehicle under dynamic conditions depends on the suspension system of the vehicle. Suspension system of a vehicle is interlinked with other systems such as steering, Wheels and Brakes. The main objective of this document is to provide complete guidance in designing and calculation of an independent suspension system with double control arms. The required parameters are calculated on considering a prototype vehicle with gross weight of 350 kg such as required stiffness of shock absorbers, Ride frequency, Motion ratio, Coefficient of damping etc. A CADD model was made with CATIA v5 r20 and SOLIDWORKS on the basis of calculations obtained and stress analysis was carried out for this model in various software such as Ansys. The complete assembled model was tested in LOTUS Shark and the result was obtained.

June 30, 2020

Industrial Engineering

Modal finite element analysis of PCBs and the role of material anisotropy

Printed Circuit Boards (PCBs) are epoxy resin-impregnated and cured sheets of counter woven glass fabric (e.g. FR4) laminated between thin sheets of Copper. The nature of the PCB is inherently anisotropic and inhomogeneous but previous modal FEMs of PCBs have assumed isotropic, anisotropic (transversely isotropic and orthotropic) material properties and shown good correlation with test data for specific scenarios [1-3]. This paper details part of a research program aimed at gaining a better understanding of accurately modeling PCB’s dynamic behavior. New investigations into the impact of material anisotropy and, in particular, the effect of material orthogonal plane definition (Ex and Ey) on eigenfrequencies is analysed. A modal FEM of a JEDEC PCB is created, verified, and validated using well established theories by Steinberg and empirical data by others [4, 5]. The relative contributions of Ex, Ey and Ez on PCB eigenfrequencies is examined using a parametric modal FEM, analysing the role of material isotropy verses anisotropy. The impact of transversely isotropic material properties is also analysed for a typical JEDEC PCB. This analysis details the mesh density required for accurately modeling the PCB eigenfrequencies. The results show that a 100 % increase in Ez has only a 0.2 % difference in the eigenfrequency where as a 100 % increase in Ey has a 1.2 % difference in the eigenfrequency. The effect of orthotropic plane definition (alternating Ex with Ey) on the JEDEC PCB amount to a 7.95 % delta in eigenfrequency.

Coilgun design and evaluation without capacitor

Capacitors with high voltage and capacity values are used in most induction coilguns that are designed and constructed. The fact that capacitors are quite bulky and slow in energy transfer and how a coilgun can be made without using capacitors is the study subject of this article. Two and four coil gun samples were made to find the essential components of an electric gun, and the results are reported in this article. The accuracy of the results is also confirmed by FEMM analysis for these models. The harmony of experimental and theoretical results shows that smaller and low cost portable electrical weapons can be a powerful alternative to firearms in the future.