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Experimental study and comparative analysis of pitting fault in spur gear system
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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
Evaluating the impact of microstructure modifications on thin film photoelectric properties
Research Article
Evaluating the impact of microstructure modifications on thin film photoelectric properties
Microstructure modifications on thin photoelectrical properties refers to changes in the microscopic structure of thin films that affect their ability to convert light into electricity. This study investigates the deposition and post-treatment effects in the electric and visual qualities of GZO, IZO, and ZnO thin layers, aiming to enhance their applicability in electronic and optoelectronic devices, according to the X-raydiffraction (XRD) examination. Thin films were deposited on glass substrates using magnetic sparking at thicknesses of 300 nm and 500 nm, followed by treatments like wet aging and annealing at 220 °C. The results showed significant improvements in crystallinity and optical characteristics, with ZnO films exhibiting a preferred (003) orientation. IZO films demonstrated notable mobility at 10.96 cm2/V-sec and resistivity of 2.49×10⁻3 ohm-cm. The novelty of this research is the novel integration of wet aging and low-temperature annealing, that notably improves thin film efficiency while maintaining structural integrity. The findings indicate that post-treatment significantly enhances the properties of these thin films, suggesting their potential for various electronic applications.
November 23, 2024
Applied Physics
Research on intelligent cutting control technology of transverse moving machine for large cross-section roadheader
Research Article
Research on intelligent cutting control technology of transverse moving machine for large cross-section roadheader
With the continuous development of the coal mine industry in our country, the cross-section of the roadway is getting larger and larger. The widely used EBZ series roadheader cannot complete the roadway cutting operation with a large cross-section at one time, so it usually needs to move the equipment left and right to complete all its cutting tasks. This paper studies the intelligent control technology of large cross-section roadway cutting, which mainly solves the positioning and attitude determination technology of roadheader in the large cross-section, and offers an accurate shape-cutting control technology and a path planning technology using a lateral moving machine. This paper proposes to combine the signals of laser sensor and fiber-optic inertial navigation system to form a combined positioning and attitude determination system, so as to make use of the advantages and avoid the disadvantages of their respective systems, and improve the accuracy of roadheader positioning and attitude determination. A swing kinematics model of the cutting arm is established, based on which the precise motion control of the first roadway section cutting and the second roadway section cutting can be realized. A key parameter calculation model of roadheader lateral moving machine is put forward to calculate the operation parameters for roadheader lateral moving machine path planning. Finally, the experimental research on intelligent cutting control technology of large cross-section roadheader is carried out in 12307 intelligent heading face of Wangjialing Coal Mine. The results show that the positioning error of the combined positioning and attitude determination system proposed in this paper is between 50-90 mm in the X-axis direction and between 25-45 mm in the Y-axis direction. The average attitude measurement error of heading angle is between 0.5 and 1.5°. This makes the technology appropriate for engineering use. The studied cutting control system achieves a cutting error of 25-50 mm for the first section, and a cutting error of 40-90 mm for the complete section. The complete section cutting error meets the ±100 mm cutting error requirement required in engineering. The intelligent cutting control technology of the lateral moving machine of the large-section tunnel boring machine studied in this paper can realize accurate cutting of the large-section tunnel of 5.6 meters. The research results of this paper provide a reference for the intelligent construction of heading faces.
November 4, 2024
Informatics
Analysis of changes in lower limb joints of athletes during the movement of wild horses’ mane parting based on biomechanics
Research Article
Analysis of changes in lower limb joints of athletes during the movement of wild horses’ mane parting based on biomechanics
In the era of fitness, more and more young people are familiar with Taijiquan, a kind of physical fitness exercise. By conducting biomechanical analyses of the movements of Taijiquan, it is possible to exercise the body better. Numerous techniques in Taijiquan make it difficult to study each individually. Therefore, this paper studied the movement of “wild horses’ mane parting” in terms of biomechanics by analyzing the joint angle, stiffness, and impulse during this movement. Twenty male athletes were selected as subjects and divided into a professional group and a beginner group according to their training periods. High-speed cameras were used to shoot the “wild horses’ mane parting” movement. The angles of lower limb joints in these athletes were measured to calculate joint impulse and stiffness. The results showed that, compared with the professional group, there were significant differences in the adduction and abduction angle and the internal and external rotation angle between the beginner group and the professional group in the single-leg support movement stage (P< 0.05). There were also significant differences in joint impulse and stiffness (P< 0.05). Compared with beginners, long-term professional practitioners can make their movements more standardized. By comparing movements and data analysis, beginners can make their movements more standardized when practicing Taijiquan and avoid the risk of sports injury. The novelty of this article lies in the use of high-speed cameras to capture athletes’ movements, enabling accurate analyses of their joints and providing effective references for precise training.
October 26, 2024
Biomechanics
Introduction of the distribution of Cs in Cu(In,Ga)Se2 photovoltaic absorbers following post-deposition treatment with CsF
Research Article
Introduction of the distribution of Cs in Cu(In,Ga)Se2 photovoltaic absorbers following post-deposition treatment with CsF
In recent years, the device performance of Cu(In,Ga)Se2 (CIGS) solar cells has been improved by heavy alkali element post-deposition treatment (Alkali-PDT). Therefore, it is of great significance to study the mechanism of enhancing CIGS device performance through Alkali-PDT. One aspect to be studied is the distribution of heavy alkali elements in the absorber. In this work, the distribution of the heavy alkali element Cs in the absorber after post deposition treatment of CsF (CsF-PDT) and its effect on the device performance are investigated. The experimental results indicate that Cs can enter both the grain interior (GI) and grain boundaries (GB) via the Cu vacancy (VCu). By comparing the distribution of Na and Cs in the film, it can be noticed that Na is mainly distributed at the GB, while Cs is not differently distributed between the GB and GI. This is mainly due to the fact that the presence of Na at GB inhibits the accumulation of Cs there. The distribution of Cs is beneficial in improving the device’s performance by passivating defects, such as InCu.
October 18, 2024
Applied Physics

Latest from engineering

Analysis of vibration characteristics of ship propeller spindle
Research Article
Analysis of vibration characteristics of ship propeller spindle
In order to obtain the vibration response characteristics of the propeller spindle system effectively and accurately, and provide the basis for the subsequent fault diagnosis, the modal simulation and test of the spindle model were carried out. With the propeller set as eccentric mass, the amplitude and torsion angle of the spindle model were simulated under the condition of excited vibration and unexcited vibration respectively, and the frequency response of bending and torsion under the coupled condition was obtained. The newmark-β method was used to solve the transient response of the bent-torsional coupling model. The results shows that when the propeller spindle system undergoes rotation at a specific frequency and experiences bending vibration excitation force, the latter will induce torsional vibration response. Moreover, the amplitude of the torsional vibration response varies with changes in the frequency of the bending vibration excitation force.
October 18, 2024
Vibration Engineering
Structural design and dynamic characteristic analysis of adjustable badminton serving machine
Research Article
Structural design and dynamic characteristic analysis of adjustable badminton serving machine
System dynamics serves as a crucial foundation for evaluating the performance of mechanical auxiliary equipment. To enhance the stability and reliability of the badminton launch process, structural design and dynamic analysis were conducted on a mode-adjustable, precise control badminton serving mechanism. The combination of eccentric crank-slider mechanism, stretched springs, and electromagnets was used in mechanical structures, which could effectively effectively improve the smoothness of the badminton in the launching process. The virtual prototype of badminton serving machine was established and imported into ADAMS for dynamic simulation analysis, verifying the correctness of the serving and retrieving mechanisms. Using the aerodynamic equations, the trajectory of badminton movement under different working parameters was simulated and analyzed. The dynamic analysis results show that the design of the launching and catching mechanisms is scientific and effective. The launch angle and initial velocity are the key factors that determine the trajectory of the badminton.
October 18, 2024
Informatics
Research on dynamic vibration absorption technology for power equipment based on energy degradation
Research Article
Research on dynamic vibration absorption technology for power equipment based on energy degradation
Aiming at the low-frequency line spectrum noise characteristics of power equipment noise, based on the principle of energy degradation, this paper combines the energy degradation sound insulation structure with the dynamic vibration absorption technology for the first time and applies it to the research field of noise control of power equipment in substations. Dynamic vibration absorption technology is used to effectively control low-frequency vibration and noise. Considering that there is an upper limit to the capacity of DVA, the sound-vibration energy degradation design of the transformer is completed by setting a sound insulation structure on the outside of the original transformer housing. It is analyzed that the vibration energy of the sound insulation structure in the specific frequency band is significantly reduced compared to the transformer housing, realizing efficient degradation of the vibration energy of the transformer housing and effective isolation of sound radiation. Through the optimized design of dynamic vibration absorption for the sound insulation structure, the structural sound isolation ability at the target frequency is further strengthened, and the system noise radiation level is greatly reduced under the action of multiple mechanisms at the target frequency, verifying the feasibility and high efficiency of the optimal DVAs energy degradation design of the transformer.
October 18, 2024
Public Health
Experimental study on the influence of different curing methods on the performance of concrete
Research Article
Experimental study on the influence of different curing methods on the performance of concrete
Curing concrete is an effective method to ensure concrete’s mechanical and durability performance. This article experimentally investigates the impact of various curing methods (air curing, sprinkler curing, geotextile curing, and composite geotextile curing) on the compressive strength of concrete at 7, 14, and 28 days, as well as the carbonation depth and chloride ion diffusion coefficient at 28, 56, and 90 days. The effects of different curing methods on concrete performance are compared. The experimental results demonstrate that sprinkler, geotextile, and composite geotextile curing at 7 and 14 days effectively enhance concrete’s mechanical and durability performance. Compared to air curing concrete at 28 days, sprinkler, geotextile, and composite geotextile curing reduced by 17.75 %, 25.11 %, and 31.51 %, respectively, but the average absolute deviation is reducing. From 28 to 90 days, air curing concrete’s chloride ion diffusion coefficient decreases by 8.5 %. For concrete specimens under sprinkler curing, geotextile curing, and composite geotextile curing, the chloride ion diffusion coefficient decreases by 20.4 %, 8.3 %, and 6.0 %, respectively. Beyond 28 days, the durability performance of concrete under composite geotextile curing, including carbonation depth and chloride ion diffusion coefficient, tends to stabilize. The optimal curing period of 28 days is determined based on comprehensive mechanical and durability performance. Composite geotextile curing retains moisture on the concrete surface, slows evaporation, reduces watering frequency and labour costs, and promotes long-term concrete performance development. Carbonation tests and durability performance, such as chloride ion diffusion coefficient, are more sensitive to concrete curing effects. Single indicators like mechanical or durability performance cannot comprehensively evaluate concrete’s long-term performance. Concrete quality should be comprehensively evaluated by considering strength, carbonation depth, chloride ion diffusion coefficient, and other indicators.
October 6, 2024
Applied Physics

71st International Conference on VIBROENGINEERING
Major Conference Topic: Vibration & Condition Monitoring Problems
Date
December 12-13, 2024
Submission deadline
Ended
Conference format
Online

Best of engineering

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A conversion guide: solar irradiance and lux illuminance
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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
Design and calculation of double arm suspension of a car
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.
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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.
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