Wear Profile Research Articles

Modelling and theoretical research on transient lubrication and wear coupling behavior of main bearing during start-up of low-speed diesel engine

This study endeavors to establish a transient mixed lubrication model for time-varying wear of main bearings under dynamic loading conditions during the startup process. This model accounts for variations in oil film thickness attributable to deformation, wear profiles, and journal misalignment throughout the operational cycle. The evolution of main bearing lubrication characteristics during the startup process was analyzed, as well as the evolution of wear profiles and their effects on lubricating properties under different numbers of startups. The results indicate that as the number of startup cycles increases, the wear rate gradually levels off. With increasing startup times, there is a decrease in contact pressure and a slight reduction in oil film pressure, resulting in enhanced lubricating performance. Furthermore, the influence of startup duration on wear is significantly greater than that of radial clearance.

Effect of hot rolling process parameters on surface wear of descaling rolls

Purpose The purpose of this study is to explain the effect of slab and roll initial temperatures on the wear characteristics of the surface of hot roll descaling rolls. Design/methodology/approach The UMESHMOTION subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique are used to investigate the wear profile of the descale roll surface and to evaluate the effect of the slab and roll’s initial temperature on the wear depth. Findings Wear is more pronounced at the edges of the roll-slab contact area and less severe in the roll-body’s central region. A rise in the initial slab temperature from 1,337 K to 1,429 K results in a 67% rise in maximum wear depth and 52% in frictional stress. The peak wear region progressively shifted toward the center of the roll body. A rise in the initial roll temperature from 308.15 K to 673.15 K caused a 46% reduction in maximum wear depth and 73% in frictional stress. The location of the peak wear region remained primarily unchanged. Originality/value This study used the UMESHMOTIONI subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique in ABAQUS® to evaluate the quantitative correlation between the wear depth of the descaling roll surfaces and the initial temperatures of the slab and rolls. This study offers valuable insights into improving the wear of descaling roll surfaces. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0231/

Influence of HPGR operating parameters on the edge and centre product – an industrial trial

ABSTRACT High pressure grinding rolls has been widely used in mineral industries as energy-efficient equipment. During the working life of an HPGR mill, the rolls’ surface wears out, and a concave wear profile (maximum wear in the middle) occurs on the rolls. As a result, a difference between HPGR discharge particle size from the middle and edges is also expected that has yet to be quantified. On the other hand, many operational variables affect the HPGR performance; however, there is an interaction between the operational variables and worn rolls. This work studied the effect of operational variables such as hydraulic pressure, rolls’ rotation speed, level of material in the hopper, and operational gap on the HPGR performance on an industrial scale. In addition, the particle size of HPGR discharge from the middle and edges of the rolls is also investigated. Results indicated that HPGR discharge from the middle of the rolls is always finer than discharge from the edges, while the difference between the discharge size from the middle and edges depended on the other variables. Furthermore, it was concluded that deeper material levels in the hopper and lower rotation speed of the rolls resulted in a finer HPGR discharge. This finding is crucial in optimising the HPGR performance and modifying the design of HPGRs to regulate the distribution of material on the rolls.

Abrasive challenge effects on enamel and dentin from irradiated human teeth: an in vitro study.

This study aimed to evaluate the effects of radiotherapy (RT) and chemoradiotherapy (CRT) on the wear and surface roughness of in vitro irradiated human enamel and dentin subjected to abrasive challenge. Enamel and dentin specimens (n = 42) were prepared from teeth donated by healthy patients and those with head and neck cancer who had received radiotherapy (RT) or chemoradiotherapy (CRT). The specimens were categorized into three groups: control, RT, and CRT (n = 14 per group for both enamel and dentin). These samples were subjected to an in vitro abrasive experiment using a brushing machine, followed by wear and surface roughness assessments with a confocal laser scanning microscope conducted before and after the abrasive challenge, considering both exposed and non-exposed areas. Statistical analysis used Shapiro-Wilk tests for normality, Wilcoxon tests for comparing two means, and Kruskal-Wallis tests. A significance level of 5% was adopted. In enamel specimens, wear profile values ​​of CRT and RT groups were not different from the control (p > 0.05). The RT group presents lower step values than the CRT and control groups (p < 0.001). No significant difference in final surface roughness was observed in all groups (p > 0.05). In dentin specimens, no significant difference in wear profile and step was observed in all groups (p > 0.05). However, CRT and RT groups present higher values in final surface roughness (p < 0.001). The exposure to ionizing radiation (associated or not to chemotherapy) influenced the surface roughness of dentin and the wear (step) of enamel after the in vitro abrasive challenge.Trial registration: Ethical procedures were approved by the FORP/USP Research Ethics Committee (CAAE: 61308416.4.0000.5419), and Hospital do Câncer de Barretos/Fundação Pio XII (CAAE: 61308416.4.3001.5437).

Research on automatic data acquisition scheme of tool profile wear based on B/S structure

Research on automatic data acquisition scheme of tool profile wear based on B/S structure

Study of the Differential Wear of Wheel Profiles on Motor Cars and Trailers of High-Speed Trains

As the operation speed of China’s high-speed trains continues to increase, a variety of complex wheel wear problems continue to emerge. Many line tests show that the differential wheel wear of the motor car and trailer car is obvious. The aim of this paper is to explore the differential wear mechanism of motor cars and trailers and their effect on dynamic performance. Firstly, this paper established a high-speed train model, which consists of two motor cars and two trailers. Then the causes of differential wear of the high-speed train from the perspective of wheel-rail contact and wheel wear were analyzed, and the Jendel wear model was used for wheel wear prediction. The wear model was verified through measured wheel wear data. Lastly, the dynamic performance of the differential wear of the high-speed train was analyzed. The results showed that the different distribution of the adhesive sliding zone in the contact patch, the different wheel-rail normal force, and tangential forces are the reasons for the differential wear. The established dynamic model and wear model can effectively predict the differential wear of the motor cars and trailer, and the maximum wear depths of the motor car and the trailer wheel were 0.886 mm and 0.721 mm. This verified the validity of the simulation model. When wheel differential wear occurs, the overall dynamic performance of the trailer is superior to that of the motor cars.

Identification of the coefficient of sliding friction from an apparent non-Coulomb behavior between wood and steel

This study investigates the sliding friction fluctuations through hysteresis cycles, observed between a steel sphere and wood specimens of beech and spruce, by using a tribometer and a profilometer. At first, the tracked wear profiles revealed a correlation between the normal force variation and the surface waviness. However, the normal force variation alone was not able to explain the observed friction force fluctuation. Hence, to explain most of the observed non-Coulomb friction hysteresis behavior, the wear-scar interaction is taken into account through an optimization framework used for data post-processing and leading to an optimal friction coefficient. A comparative study showed similar values between the identified optimal friction coefficient, the mean and energy-based friction coefficients.

A novel IoT sensor and evolution model for grinding mill liner wear monitoring

Tracking mill liner wear is essential for improved plant reliability and grinding performance. This study developed a novel IoT wear sensor and a Discrete Element Modelling coupled methodology to predict and continuously evolve shell liner’s wear pattern. The IoT sensor was purposely developed to track and report the live thickness of a shell liner. Global wear pattern was then obtained by coupling the qualitative wear intensity obtained in DEM and sensor results, from which a topological evolution model was established to generate the shell liner’s progressive wear profiles. Predictions of the wear evolution model were compared with 3D laser scan measurements collected during operation. Results indicated that the wear evolution model showed less than 8% error with laser scan measurements in quantitative wear rate comparison.

Research on the influence of time-varying wear of wheel-rail profile on vehicle dynamic response

Employing a combination of field measurements and numerical simulations, this study initially evaluates the impact of simplifying wheel-rail profile wear on the calculation results of vehicle performance indicators. Subsequently, it investigates the influence of time-varying wear of wheel-rail profiles on the vehicle’s dynamic response, along with an analysis of change law in wheel wear depth and range under different wheel-rail profiles. The finding indicates that simplifying wheel-rail profile wear notably affect the accuracy of predicting wheel wear, with potential maximum prediction errors of up to 84 % compared to actual conditions. Furthermore, changes in the wheel-rail profile resulting from wear significantly impact the vehicle’s straight-line running performance and curve negotiation performance, particularly in the early and later stages of wheel-rail wear. Moreover, profiles in the mid-term wear stage significantly exacerbates wheel wear depth, demonstrating a maximum increase 4.33 times higher than that of the standard profile.

Design of an Innovative Twin-Disc Device for the Evaluation of Wheel and Rail Profile Wear

Design of an Innovative Twin-Disc Device for the Evaluation of Wheel and Rail Profile Wear

Experimental investigations and finite element simulation for predicting wear life of overrunning clutches

An overrunning clutch, generally known as a freewheel clutch, is a direction dependent torque transmitting device that works on the principle of wedge friction. The overrunning wear characteristics of freewheels are studied using pin-on-disc tribometry. The wear experiments for freewheels are performed at accelerated loads to promote wear in a short period. The overrunning wear life of the clutch under operating conditions is predicted using an appropriate load-life relationship. A finite element-based Archard’s wear model is implemented as a numerical strategy to evaluate the wear profile. The maximum local wear for various loads is computed using experimentally obtained wear and friction coefficients. The numerical simulation is performed with an adaptive mesh technique utilizing incremental nodal displacements to predict surface wear. The experimental and numerical results are compared in terms of wear characteristics. The numerical wear results are almost 11% higher than the experimental results. The wear life of an overrunning clutch is predicted in terms of overrunning speed based on the wear amount.

CALCULATION OF WEAR VELOCITY IN PROFILE PART OF CAM

In the article, taking into account the increasing wear of the profile, the intensity of wear of the surface of the cam in contact with talc during operation is studied, and the change in this intensity depending on the pressure angle is estimated. The effect of chamber profile wear on the gas distribution mechanism (GDM) and engine operation has been studied. the possibility ofa significant improvement in the tribological properties of a cam-pusher pair is analyzed on the basis of a numerical method for formulating the law of motion of the pusher.

Error correction method based on dual-beam laser for curved rail profile measurement

The current method of dynamic rail profile measurement involves the installation of a line-structured light sensor at the base of the train. The accuracy of this measurement is influenced by the vertical relationship between the laser plane of the light sensor and the longitudinal direction of the rail (LDR). When a train travels in a straight line, the normal of the laser plane aligns with the LDR. However, when the train curves, the angle at which its wheels connect with the rails causes the laser plane’s normal direction to deviate from the LDR, leading to measurement errors. To address this issue, we propose a method for curved rail profile measurement using a dual-beam laser to correct these errors. This method involves generating an auxiliary 3D rail reflecting the LDR and a virtual 3D rail reflecting the normal direction of the laser plane from the cross-section image of the dual-beam laser. An optimization function is then formulated to determine the optimal auxiliary plane (optimal-AP) by analyzing the alignment or intersection between the auxiliary and virtual 3D rails. Distorted contour points are projected onto the optimal-AP to rectify errors. Experiments validate the accuracy and effectiveness of this proposed method. The results show that, regardless of pitch or yaw movement between the laser plane and the LDR, the error in measuring corrected profile wear remains consistently below 0.10 millimeters, thereby meeting the accuracy standard for rail wear measurement. This approach rectifies measurement errors in curved rail profiles from a 3D perspective, ensuring accurate measurements even under complex working conditions. It also provides a valuable reference for error analysis and improving dynamic rail profile measurement accuracy.

Identification of optimal accelerometer placement on trains for railway switch wear monitoring via multibody simulation

Accelerometers play a crucial role in the railway industry, especially in track monitoring. Traditionally, they are placed on the railway tracks or often on bridges to monitor the health and condition of the infrastructure. Recently, there has been an increased focus on using regular trains to monitor the condition of railway infrastructure. Often, the sensors are placed based on certain assumptions without much scientific evidence or support. This paper utilizes the multibody simulation software GENSYS to identify the optimal placement of accelerometers on a passenger train for monitoring railway switch wear. Switch wear profiles were generated systematically and used as input for the simulations, studying acceleration at a total of 93 locations distributed among the wheelsets, bogies, and carbody. Based on both time and frequency domain analyses, optimal sensor locations were identified, generally close to the first bogie or wheelset at the leading carbody. Accelerations generated by the wheelset passing the switch can also be captured in the carbody, but it is important to note that these are several orders lower in magnitude compared to the acceleration on the wheelset. If accelerometers are to be placed in the carbody, correct sensitivity must be chosen, and a high-pass filter should be applied to capture the acceleration signals associated with switch wear. The study confirms that there is a direct correlation between the depth of switch wear and the magnitude of the acceleration. It remains effective even under various curve radii and train speeds.

Nonlinear stability evolution of railway wagon system due to wheel profile wear

Nonlinear stability evolution of railway wagon system due to wheel profile wear

Fretting wear behaviour of high strength alloy steel induced by plasma nitriding and post-oxidation

Fretting wear is caused by a relative movement of the material surface on a small scale. Finding ways to reduce fretting wear is of great importance for extending equipment life and reducing maintenance costs. With the increase of load, the effecrt of fretting wear adhesion of surface treated material becomes more obvious. The materials treated with post-oxidation have stronger wear adhesion than those treated only with plasma nitriding, but the total wear volume is reduced. In this paper, the fretting wear of high strength steel alloy with different surface treatments is simulated by the finite element method. The coefficient of friction and wear volume can be obtained from the experimental results, and the wear coefficient is calculated using the wear energy model. The predicted two-dimensional wear profile curves (U-shape and W-shape wear profiles) under different wear conditions are compared with the experimental results. The W-shape wear profile is used to describe the adhesion state of the worn surface. In addition, the surface deformation and mechanical properties of U-shape and W-shape wear profiles are analysed. The simulation results show that double-sided wear and the addition of adhesive layer is important for the prediction of wear characteristics.

The effect of NaCl concentration on impact-sliding fretting corrosion behavior of Inconel 690TT heat transfer tubes

PurposeThe purpose of this paper is to investigate the effect of NaCl solution with different concentrations on impact-sliding fretting corrosion behavior of Inconel 690TT steam generator heat transfer tubes.Design/methodology/approachThe optical 3D profiler was used to measure the wear profile and calculated the wear volume. Corrosion behavior was studied using open circuit potential monitoring and potentiodynamic polarization testing. The morphologies and elemental distributions of wear scars were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. The synergism of wear and corrosion was analyzed according to the ASTM G119 standard.FindingsThe corrosion tendency reflected by OCP and the corrosion current calculated by Tafel both increased with the increase of NaCl concentration. The total volume loss of the material increased with concentration, and it was known from the synergism that the volume loss caused by corrosion-enhanced wear accounted for the largest proportion, while the wear-enhanced corrosion also made a greater contribution to volume loss than tangential fretting corrosion. Through the analysis of the material morphologies and synergism of wear and corrosion, the damage mechanism was elucidated.Originality/valueThe research findings can provide reference for impact-sliding fretting corrosion behavior of Inconel 690TT heat transfer tubes in NaCl solution with different concentrations.

Performance degradation model and life prediction method of spool pair caused by erosion wear

The erosion of solid particles in the fluid causes the wear of the metering edge of the spool pair, resulting in a decrease in system performance. This paper aims to develop a general method to evaluate performance degradation and life prediction of spool pairs induced by erosion. Considering the diversity of influencing factors and the complexity of operating conditions, traditional numerical calculation methods will consume huge computational costs. It is difficult to qualitatively and quantitatively analyze the evolution of metering edge by numerical calculation. The erosion prediction model (EPM) constructed by machine learning methods can be used to predict the wear profile discretized in time and space. Combined with the mathematical model of the valve-controlled cylinder, a performance degradation model (PDM) that can simulate real-time working conditions is established. Through the data exchange and iterative update between EPM and PDM, a complete digital platform for the calculation of slide valve durability is constructed. After comparing with the experimental results, it can be concluded that the proposed method can realize the performance degradation evaluation and life prediction of the spool pair caused by erosion wear under continuous working conditions.

Fretting Wear Behavior of Fluorine Rubber and Short Carbon Fiber Reinforced Fluorine Rubber Matrix Composites

The fretting wear behavior of fluorine rubber (FKM) and short carbon fiber (SCF) reinforced fluorine rubber matrix composites (SCF/FKMCs) is investigated experimentally under air condition. Four kinds of SCF/FKMCs with different SCF concentrations (5 phr, 10 phr, 15 phr, and 20 phr in every 100 phr of FKM) are considered. The contact model utilizes the sphere-on-flat contact between a 440 C stainless steel ball and an FKM or SCF/FKMCs coating perfectly bonded to a ceramic sheet in fretting experiments. The impacts of SCF concentration, normal force, and displacement amplitude on the fretting wear behavior are investigated. Scanning electron microscope (SEM) is used to analyze the fretting wear surface morphology and wear mechanism, while three-dimensional (3D) white-light interference profilometer is used to describe the characteristics of 3D surface wear profile and determine the wear volume. The fretting wear performances of FKM and SCF/FKMCs with different SCF concentrations are compared under different fretting test conditions. The results show that adding an appropriate amount of SCFs to FKM can improve wear resistance and reduce the coefficient of friction (COF). SCF/FKMC with SCF concentration of 15 phr has the smallest COF. SCF/FKMCs with SCF concentration of 5 phr or 15 phr have the best wear resistance for small normal force or large displacement amplitude.

Surface wettability and tribological performance of Ni-based nanocomposite moulds against polymer materials

In the mass-production of microfluidic devices through micro hot embossing/injection moulding, the longevity of mould inserts is influenced by elevated adhesion and friction between the polymer and the mould. Thus, accurate prediction of mould lifespan requires a comprehensive understanding of surface wettability and tribological performance during polymer contact. The current study addresses this gap by characterizing fabricated micro-structured Ni, Ni-WS2, and Ni-PTFE nanocomposite moulds (surface morphologies, crystal structures and microhardness) to investigate inherent lubrication mechanisms. Surface wettability of mould material was systematically studied by measuring the contact angles with eight different polymer melts. Pin-on-disk tests with polymer pins made of cyclic olefin copolymer (COC 8007), polypropylene (PP), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were conducted to elucidate the wear resistance of the nanocomposite moulds. Pressure-dependent friction coefficient and wear resistance were further explored under increasing external loads, simulating the actual moulding processes where contact pressure may vary considerably depending on the part shape. Results indicate that Ni-WS2 exhibits the highest microhardness (532 Hv), followed by Ni-PTFE (465 Hv) and Ni (198 Hv). Notably, Ni-PTFE demonstrates exceptional hydrophobicity against all polymer melts, signifying low surface energy during polymer contact. Moreover, both nanocomposite moulds exhibit reduced friction coefficients and enhanced wear resistance across various polymers. Counterintuitively, despite its lower hardness, the Ni-PTFE mould displays superior wear resistance against the COC pin under higher loads, while the Ni-WS2 mould experiences severe adhesive wear, as observed from wear morphology and profile analysis. This finding establishes the Ni-PTFE as a promising alternative as a mould insert material for precision manufacturing.