Wheel Surface Research Articles

Spinning a Liquid Wheel and Driving Surface Thermomagnetic Convection with Light.

A typical Tesla thermomagnetic engine employs a solid magnetic wheel to convert thermal energy into mechanical energy, while thermomagnetic convection in ferrofluid is still challenging to observe because it is a volume convection that occurs in an enclosed space. Using a water-based ferrofluid, a liquid Tesla thermomagnetic engine is demonstrated and reports the observation of thermomagnetic convection on a free surface. Both types of fluid motions are driven by light and observed by simply placing ferrofluid on a cylindrical magnet. The surface thermomagnetic convection on the free surface is made possible by eliminating the Marangoni effect, while the spinning of the liquid wheel is achieved through the solid-like behavior of the ferrofluid under a strong magnetic field. Increasing the magnetic field reveals a transition from simple thermomagnetic convection to a combination of the central spin of the spiky wheel surrounded by thermomagnetic convection in the outer region of the ferrofluid. The coupling between multiple ferrofluid wheels through a fluid bridge is further demonstrated. These demonstrations not only unveil the unique properties of ferrofluid but also provide a new platform for studying complex fluid dynamics and thermomagnetic convection, opening up exciting opportunities for light-controlled fluid actuation and soft robotics.

Numerical simulation and experimental study of micro-structured surface of sapphire ground by structured grinding wheel

The efficiency and form accuracy of micro-structured surface preparation can be greatly improved by using structured wheels to grind micro-structured surfaces. In this study, the structural design of the grinding wheel surface was first carried out. Then, the geometric analysis of the designed structured 3D model of the grinding wheel is carried out to establish a numerical model for grinding micro-structured surfaces with structured grinding wheels and to investigate the effects of different velocity ratio, grinding depth and dressing angle on the size and distribution of surface microstructures. Finally, the surface of the grinding wheel is structured using wire electrical discharge machining (WEDM) technology, and the microgroove grinding experiment on the sapphire surface is carried out. The research results show that the established numerical simulation can accurately describe the formation mechanism of micro-structured surfaces ground by structured grinding wheels. At the same time, it is found that the shape of micro-grooves on the sapphire surface ground by the structured grinding wheel is basically complete. This further shows that the technology developed in this research can produce the micro-structured surfaces with good quality.

Trajectory planning of deep-cutting laser profiling of superabrasive profile grinding wheels

The low profiling efficiency is the key barrier to the industrial application of laser dressing technology for profile grinding wheels. In this paper, the trajectory planning method of deep-cutting laser profiling was proposed for the first time, the theoretical model of the energy distribution of the Gaussian laser beam on the surface of the profile grinding wheel was established, and the effect of this method on improving the profiling efficiency of superabrasive profile grinding wheel was systematically studied. Through comparative experiments, it was confirmed that the trajectory planning method could effectively improve the profiling efficiency of the V-shaped grinding wheel, and it was found that the smaller the tip angle, the greater the efficiency improvement. The change of grain size will lead to the change of grain removal method, which will affect the profiling efficiency of V-shaped grinding wheel, but it has little influence on the profiling accuracy. The V-tip arc radius of the diamond grinding wheel with a particle size of 20–180 μm after laser profiling could be controlled between 10 and 20 μm, which was difficult to achieve by mechanical or electrical dressing method. The trajectory planning method could also significantly improve the profiling efficiency of convex/concave arc-shaped grinding wheels, and the greater the arc radius or chord-to-diameter ratio of the grinding wheel, the greater the efficiency improvement. Even though convex/concave arc-shaped grinding wheels were the same size, their profiling efficiency and material removal efficiency were quite different. For grinding wheels with different arc radii or chord-to-diameter ratios, different process strategies should be selected during laser profiling to ensure a comprehensive balance between efficiency, accuracy and quality.

High magnetic performance ultra-thin Fe-6.5Si ribbons fabricated by planner flow casting and annealing

Fe-6.5 wt.%Si steel is one of the most attractive soft magnetic materials for making iron cores with low noise and low power loss. The planner flow casting method was regarded as a promising method to obtain ultra-thin ribbons of Fe-6.5Si alloy. In this study, Fe-6.5Si ribbons with a thickness of 0.03 mm were prepared by planner flow casting. Samples were heat-treated at various temperatures. It is revealed that the grain size on the wheel surface and free surface gradually increases with increasing annealing temperature. The initial {100} fiber texture of the wheel and free surfaces is weakened after annealing, transforming to {001} 〈510〉 on the wheel surface and to {229} < 11 2 2 > on the free surface after annealing at 1150 °C for 1 h. The texture parameter and dislocation density are the key factors affecting the magnetic induction intensity, showing an inverse correlation with the texture parameter and dislocation density. Furthermore, the iron loss is mainly influenced by the grain size, with an optimal grain size of 10 μm. Considering the magnetic induction intensity and iron loss, the optimal annealing temperature is determined to be 1100 °C, resulting in a magnetic induction intensity of B8 = 1.26 T and B50 = 1.65 T, and iron loss values of P1/400 = 14.1 W/Kg and P0.2/5000 = 11.1 W/Kg.

Research on topological grinding of bionic structured scale surface for reducing contact friction and fluid drag resistance

The structured scale surface is an important functional surface that reduces the drag resistance of fluids and contact friction resistance. In order to grind the bionic scale structure on the workpiece, based on the topological theory and the principle of grinding kinematics, a novel topological grinding strategy was proposed. To this end, the topological feature vectors of the structured scale surface and the grinding wheel surface were established by analyzing the biomimetic structured scale surface; The Topological space of grinding process is constructed and the topological mapping equation of grinding process is established; The feasibility of this grinding strategy was verified through simulation and grinding experiments. The research results indicate that the established topological mapping equation is correct; Under the condition of maintaining design parameters, the errors of the feature parameters of the ground structured scale surface are between 2.8% and 8%; As the grinding parameters change, the feature parameters of the ground scale surface will also change, but they can still maintain the same topological attributes as the designed scale surface. Therefore, the proposed topology grinding strategy is feasible.

An Experimental Investigation of the Effects of Dressing and Grinding Parameters on Sustainable Grinding of Inconel 738 Used for Automated Manufacturing

The significant effect of the dressing process on the surface of the grinding wheel (GW) and the need to provide an optimal dressing condition are the requirements of reduction machining time and energy consumption in the sustainable grinding process. In this study, for the first time, the results of changes in the parameters of the dressing process and changes in the topography of the grinding surface on the surface roughness of the Inconel 738 have been presented using single-edge and four-edge diamond dressers. The use of minimum quantity lubrication (MQL) and wet condition are other variables in this study to reduce the consumption of cutting fluid and prevent its destructive effects on the environment. The results indicate that the MQL technique increases the grinding performance of Inconel 738 by reducing ground workpiece surface roughness and decreasing the coolant–lubricant consumption comparing to the conventional wet grinding process. Additionally, it has been found from the experimental results that applying a single-edge dresser generates finer topography on the grinding wheel and, consequently, has a better surface finish in the grinding process compared to the multipoint diamond dressing tool with the same dressing and grinding parameters. In other words, increasing the dressing feed rate during dressing of the grinding wheel using a multipoint dresser makes a finer wheel surface topography and as a result decreases the surface roughness of the ground workpiece compared to a single-edge dresser. With multipoint diamond tools, the grinding performance during the life of the dressing tool also tends to remain more consistent, which is a definite advantage in automated production. Therefore, application of a multipoint dresser leads to a reduction in dressing time and increased production capability.

Wear and RCF problems of metro wheel/rail systems: Phenomena, causes and countermeasures in China

Wear and rolling contact fatigue (RCF) problems observed on metro wheel/rail systems in China in the last 15 years are summarized and explained from the aspects of phenomena, causes, and validated countermeasures. Presented wheel/rail wear in the lateral direction includes wheel flange wear, rail side wear, and abnormal wear of wheels such as differential, hollow, groove, and channel wear. As for irregular wear on wheel and rail running surfaces, the focus is on four and two important cases for wheel and rail, respectively, i.e., low-order wheel polygonal wear, high-order wheel polygonal wear, wheel stochastic out-of-roundness (OOR), wheel corrugation, short-pitch rail corrugation on the tracks with resilient and conventional fasteners, and rail corrugation on damping sleeper tracks. Finally, some unusual RCF problems occurring on wheel and rail surfaces are presented.

Experimental study on the effect of solid lubricants on wheel rail contact wear and surface hardness evolution

PurposeThe CL60 steel wheels of subway vehicles operating on specific lines require frequent refurbishment due to rapid wear and tear. Considering this issue, MoS2-based and graphite-based solid lubricants are used to reduce the wear rate of subway wheels and extend their service life.Design/methodology/approachUnder laboratory conditions, the effect of MoS2-based and graphite-based solid lubricants on the friction and wear performance of subway wheels and rails was evaluated using a modified GPM-60 wear testing machine.FindingsUnder laboratory conditions, MoS2-based solid lubricants have the best effect in reducing wheel/rail wear, compared to the control group without lubrication, at 2 × 105 revolutions, the total wheel-rail wear decreased by 95.07%. However, when three types of solid lubricants are used separately, the hardness evolution of the wheel-rail contact surface exhibits different characteristics.Practical implicationsThe research results provide important support for improving the lifespan of wheel and rail, extending the service cycle of wheel and rail, reducing the operating costs of subway systems, improving the safety of subway systems and providing wear reduction maintenance for other high wear mechanical components.Originality/valueThe experiment was conducted through the design and modification of a GPM-60 testing machine for wear testing. The experiment simulated the wheel-rail contact situation under actual subway operation and evaluated the effects of three different solid lubricants, MoS2-based and graphite-based, on the wear performance and surface hardening evolution of subway wheel-rail.

Reducing Wheel Loading in the Grinding of Titanium Alloys through Ultrasonic-Assisted Plasma Oxidation Modification

To reduce wheel loading caused by chip adhesion in the grinding of titanium alloys, a new method named ultrasonic-assisted plasma oxidation modification grinding is suggested. The processing principle was introduced in this research, and based on that, the experimental apparatus was established. Then, the surface and cross-sectional morphologies of a workpiece with an oxide layer were characterized, followed by the detection of its microhardness and surface composition. On this basis, in the absence and presence of the oxide layer, the dynamic changes in wheel loading on the grinding wheel surface and the evolution behavior of chip adhesion on the grains were both investigated after gradually increasing the grinding passes. Finally, the effects of wheel loading on the ground surface morphologies were analyzed. The results showed that the oxide layer with low microhardness was mainly composed of TiO2 and Al2O3. Moreover, with an increase in grinding passes, the overall occupied area of chip adhesion on the grinding wheel surface increased proportionally in the absence of the oxide layer, which finally caused severe wheel loading. Conversely, yet at almost the same rate, the overall occupied area of chip adhesion increased after remaining comparatively unchanged in a short range of grinding passes in the presence of the oxide layer, which effectively inhibited the wheel loading. Compared with the ground surface obtained without an oxide layer, the generation of plastic-stacking was significantly restrained with the assistance of the oxide layer, thereby improving the ground surface quality.

Modeling bulk modulus of abrasive cloth wheel and polished surface roughness for polishing blade with abrasive cloth wheel

Modeling bulk modulus of abrasive cloth wheel and polished surface roughness for polishing blade with abrasive cloth wheel

Studying the load of composite brake pads under high-temperature impact from the rolling surface of wheels

The object of the research is the processes of thermal stress, perception and redistribution of loads by the brake composite pad during braking of the car in operation. In the current conditions, wedge-dual wear of composite brake pads is observed in the braking systems of freight cars, the feature of which is the deterioration of the braking efficiency of freight trains. With this type of wear, both an increase in the load on the brake pad and an "underuse" of the amount of pressure on it can occur. A comprehensive thermal calculation was carried out for composite brake pads with uniform and wedge-dual wear. The results of the calculation showed that the amount of pressure on an abnormally worn pad is 23.3 % less than that acting on a pad with nominal values. It has been proven that the change in the pressure force on the composite pad with different values of the wear parameters during braking leads to a change in the braking force that occurs between the wheel and the rail during braking. The calculation of the strength of the composite brake pad with wedge-dual wear was carried out. The obtained results will make it possible to develop measures to modernize the elements of the brake lever transmission of freight cars. The field of practical use of the obtained results is car-building enterprises. The conditions for the practical use of the results are the brake lever transmissions of carriages of cars with a gauge of 1520 mm. The conducted studies prove the negative impact of wedge-dual wear not only on braking efficiency, but also on the strength of brake pads. This makes it necessary to create measures aimed at its elimination, which will contribute to increasing the level of train traffic safety and significantly reducing the operational costs of maintaining freight cars

Ultrasonic Thread Surface Inspection of Railroad Car Wheels and Locomotive Tires Using Rayleigh Waves

Ultrasonic surface inspection of cylindrical objects using the Rayleigh wave echo method has many advantages. Despite strict requirements for surface cleaning, the method is widely implemented in industries and transport, for example on the all-rolled wheel thread or tires of railroad rolling stock. Taking into account the ability of the Rayleigh wave transducer to receive waves with a side ('back') lobe of the ray diagram, the influence of possible contamination or excess of contact fluid on the input surface on the control results, it becomes particularly difficult to explain the position and amplitude of the signal. Using mathematical modeling and experimental studies, the ray diagrams of Rayleigh wave piezoelectric transducers with the 'back lobe' characteristic of piezoelectric transducers of this type were obtained. The efficiency of emission and (or) receiving depends on the parameters of control and apparatus; this effect is more evident if the width of the transducer piezoelement deviates (e.g., during fabrication) and the frequency varies within 20 %, allowed by GOST R 55724-2013. The acoustic path of the Rayleigh wave reflected from the flaw with a diameter of 7 mm on the wheel thread is experimentally constructed and tested on the model. It is shown that the amplitude of the echo-signal changes nonuniformly, the local maxima obtained experimentally reach 9 dB relative to the exponential relation characteristic of propagation over a boundless surface. The reason for such phenomena lies in multiple re-reflections of waves from the boundaries on the tread surface of railway wagon wheels and locomotive tires (rim chamfer, ridge to ridge transition) and their further interference.

Доңғалақ пен рельстің өзара әрекеттесу жүйесінің ағымдағы жағдайы

The article considers the current state of stable interaction of the wheel-rail system, one of the main and resource-intensive problems that has long remained acute in the field of railway transport. The types of wear between the wheel and the rail have been thoroughly studied, and the results are shown in a graph and diagram. It can be seen from the results that intensive wear of the rolling surface of wheels and rails on curved sections of the road prevails over other types of wear. So far, many proposals have been proposed and work has been done to prevent this wear and tear. However, the work done clearly showed that it was not possible to completely solve the problem of intensive wear of wheels and rails on curves. The costs of material resources associated with excessive wear of the wheel-rail system in the locomotive, wagon and road facilities, primarily on curved sections of the track, are at a fairly high level. Therefore, it is necessary to continue work on their reduction.

Мокрій Т. Ф., Малишева І. Ю. , Лапіна Л. Г., Пасічник С. С. Взаємодія з рейками коліс пасажирського вагона з новим профілем ободу ІТМ-73EP в криволі-нійних ділянках колії

Speeding up the integration of Ukraine into the European railway transportation is an important task in the current development of the Ukrainian railway transport. Currently, the most effective way to travel across borders between countries with different track gauges is the use of gauge-changeable wheelsets. Continuous traffic on the Ukrainian (1520 mm gauge) and European (1435 mm gauge) railways calls not only for gauge changing facilities, but also for the compatibility of the wheel-rail contact pair on both railways: R65 rails and a cant of 1/20 in Ukraine and UIC60 rails and a cant of 1/40 in Europe. At the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, a new wear-resistant wheel profile, ITM-73ER, was proposed. As predicted, its use in passenger cars will offer dynamic stability and a high dynamic performance throughout the range of operating speeds on the Ukrainian and European railways and acceptable indices of wheel – unworn rail interaction on both railways. In service, the shapes of the wheel and rail contact surfaces change due to wear, especially in curves. Because the Ukrainian and European railways mostly use wheel and rail profiles of their own, the use of the new wheel profile may impair the wheel–rail interaction process, enhance wheel flange wear, and shorten the wheel life. The goal of this work is to study the effect of the in-service rail head shape change in curves of the Ukrainian and European railways on the wheel–rail interaction indices of a passenger car with ITM-73ER profile wheels. The head shapes of outer rails of the Ukrainian and European railways’ circular curves were predicted for a side flange wear changing from 0 to 8 mm in 2 mm increments. The calculations were made for two circular curves of radius 300 m with UIC60 rails and a cant of 1/40 (Europe) and R65 rails and a cant of 1/20 (Ukraine). To speed up the prediction, it was assumed that the curves were traveled by four-axle fully loaded freight cars, which maximizes the rail wear. The freight car wheels were assumed to be unworn and machined to the S1002 profile (for the European railways) and to the standard profile specified by the Ukrainian State Standard GOST 10791:2016 (for the Ukrainian railways). Using the computed head shapes of R65 and UIC60 rails differing in wear degree, a study was conducted into their effect on the wheel–rail pair strain and stress field and the dynamic indices of car–track interaction for passenger cars with ITM73-ER profile wheels negotiating a circular curve of radius 300 m. It was shown that the use of the ITM-73ER wheel profile in passenger cars will offer improved indices of car–track interaction, for worn rails too, both on the Ukrainian railways and in the combined operation on the Ukrainian and European railways.

Progress in grinding performance by additive manufacturing of grinding wheels integrated with internal venturi cooling channels and surface slots

Among the most promising features of additive manufacturing are tool or form-free manufacturing and the ability to create intricate geometries that are difficult or even impossible to fabricate with traditional methods. These advantages can be employed to produce enhanced grinding tools. Efficient coolant fluid delivery into the cutting zone of the grinding operation has been a challenging problem since high frictional contact in the arc zone deteriorates the resin bond and lessens the grinding performance. This research study was dedicated to assessing the influence of internal cooling along with surface structures on the grinding performance of resin-bonded grinding wheels fabricated via additive manufacturing. This research introduced a novel structure that benefits from internal venturi shape cooling channels to provide exceptional fluid velocity in the tool and workpiece interaction zone. The grinding wheels have been produced employing vat photopolymerization. Grinding experiments with and without internal cooling were conducted on an aluminium plate to study the impact of introduced structures on the main aspects of grinding performance, such as cutting forces, surface roughness, tool wear, and dimensional accuracy. Two different grinding scenarios comprising shallow (10 μm depth of cut) and deep grinding (100 μm depth of cut) were carried out to reveal the influence of the material removal rate on the grinding experiments. The measured grinding forces revealed that integrating internal cooling channels and surface slots in a grinding tool could significantly reduce the grinding forces, which was more pronounced in the case of using venturi channels. Measured tool wear and dimensional accuracy together with calculated grinding ratio revealed that using cooling channels could participate in a notable increase in tool life and material removal ability, especially for venturi channels, due to improved cutting conditions, by which higher dimensional accuracy was obtained as well for the ground parts. Besides, it was discovered that the cooling channels could improve the surface quality of the ground part, which was less noticeable with the venturi channel grinding wheel. Furthermore, the optical and confocal microscopy detection confirmed that internal cooling channels could reduce chip loading on the grinding wheel surface, decrease the required number of dressing intervals, and cause effective promotion of tool life.

The use of Preston equation to determine material removal during lap-grinding with electroplated CBN tools

Grinding executed in a lapping configuration is an alternative finishing process benefiting from both grinding and free-abrasive machining, while minimizing the heat effect impact. Electroplated tools can be effectively used in different abrasive processes, including high-speed grinding, however, the assessment of machining performance over time is a key factor in their correct use to achieve satisfactory technological results. In conventional grinding, bigger grain-coverage provides better results due to the higher bonding strength of grains. In lap-grinding, fracturing and crushing of the abrasive particles initially covered by the plating result in a suspension which is typically dosed continuously in free-abrasive machining. Due to this, the process transforms from two-body (grinding) to three-body abrasion (free abrasive machining) which may result in reduced grinding performance approaching asymptotically a specific value while improving surface finish. The main aim of the presented study is the evaluation of electroplated CBN tools used in lap-grinding of 40H alloy steel workpieces whose hardness was 54 HRC. The obtained results and observations of the working surface of CBN wheels and workpieces allowed for the identification of the wear characteristics for three nickel plating thicknesses corresponding to 35%, 50% and 65% of the nominal CBN crystal size and for specific process parameters. The surface roughness Ra parameter decreased gradually from the initial value 1.9 μm to the values below 0.7 μm for bigger B107 grains and for all plating thicknesses. For smaller B64 grains, the surface roughness and waviness parameters reached similar values to those obtained for the larger B107 grains at corresponding processing times. The lowest value of Ra parameter below 0.4 μm was obtained for B64 grains and for the thinnest plating but with a 50% reduction in material removal comparing to B107 grains. The Preston equation was employed to calculate the material removal as a function of time under variable process conditions in the machining zone due to the tool wear. This attempt extended the range of the material removal modeling, despite the fact that the electroplated wheels were subject to wearing down resulting in the gradual reduction in the efficiency, as well as in the change of the working conditions in the workpiece-tool contact zone.

Laboratory investigations of triboelectric charging of dust by rover wheels

The dusty plasma environments of airless bodies present challenges for both exploration and science missions to their surfaces. Objects moving on the surface, such as rover wheels, transfer charges onto regolith dust due to the triboelectric effect. The charged dust particles can readily stick to spacesuits as well as the optical, electronic, and mechanical components of equipment and instruments, causing their degradation. This effect is more pronounced in permanently shadowed regions (PSRs) of the Moon, where the charge dissipation rate is low due to a lack of ambient plasma. Here we report the first results of an experimental investigation of the tribocharging effect between dust and rover wheels. Various wheel surface materials along the triboelectric series are selected. The effects of varying wheel speeds and dust types are explored. Results indicate that charge distributions conform to the triboelectric properties of the dust and material it comes into contact with. High charges of up to ∼2 pC are measured on dust grains ∼100 μm in diameter, which is equivalent to a surface potential of few hundred volts. Results also suggest that higher wheel speeds may result in more dust-dust interactions, changing the charging behavior of the dust grains. These findings indicate a need for future studies to better understand tribocharging in various exploration scenarios in order to design effective dust mitigation strategies and methods.

Different responses of wheel–rail interface adhesion and wheel surface damage induced by an out–of–round wheel tread

The out–of–roundness of wheel treads are an inherent degradation characteristic of the wheels of railway vehicles, and the interface behaviour of the wheel and rail caused by out–of–roundness features has essential research value in high–speed train running safety and quality. Sliding–rolling contact wear testing was conducted to evaluate the effect of the out–of–round wheel on the wheel–rail damage behaviour, by using a twin–disc setup. The effects of four wheels, three wheels of different eccentricities and one normal wheel were taken as a control group. The characteristics of the wheel–rail interface adhesion, wheel surface damage and compressive residual stress (CRS) distribution were compared and analysed. The results showed a dramatic increase in the fluctuation amplitude of the wheel–rail vertical force of the eccentric wheels, and the adhesion coefficient of the wheel–rail interface significantly decreased. Furthermore, eccentric wheels dramatically accelerate the wear loss of the rail used as a counterpart during wheel–rail rolling contact. The surface damage behaviour of the eccentric wheels is obviously different along the circumferential direction, and non–uniform wear was observed. The damage mechanism of the worn surface presented varying characteristics, which could be divided into a severely damaged zone (located at the maximum of the rolling radius rmax) and a slightly damaged zone (located at the minimum of the rolling radius rmin). The surface contact stress of the severely damaged zone was high, this finding can be explained by the extremely rough worn surface caused by the severe fatigue delamination characteristics and the initiation and propagation of fatigue cracks in the severely damaged zone. Furthermore, the values of surface hardness and residual stress were relatively low. By contrary, an adhesion layer was observed on the worn surface of the slightly damaged zone. The adhesion layer protects worn surface in the slightly damaged zone was relatively flat, and the CRS was relatively high.

Numerical thermo-mechanical analysis of a railway train wheel

Abstract In this paper, the variation of thermal stresses, strains and deformations created by combined thermal and mechanical loads is investigated in block braked railway wheels. Thermo-mechanical analyses of the railway wheel were performed by using finite element (FE) for the numerical analysis. Before performing FE analyses, input parameters, e.g. heat flow, heat conduction, heat convection, applied loads and boundary conditions were transferred from railway wheel conditions in reality. The thermal analysis of wheel structure in the analysis calculation was evaluated experimentally, and validated with numerical result used in current model. In this purpose, ANSYS Workbench module package was used to simulate the distribution of stress and temperature field over the wheel. Combined thermal and mechanically induced damage surfaces of the railway wheel in reality were compared with numerical results in ANSYS. It was concluded from the results that 3D simulations in this wheel model showed a significant effect of thermal loading rather than mechanical loading on wheel braking tread, and combination of thermal and mechanical loading caused the detrimental effect on railway wheel structures those used in this model.

Online prediction of grinding wheel condition and surface roughness for the fused silica ceramic composite material based on the monitored power signal

The fused silica ceramic matrix composite (SiO2f/SiO2) is characterized as one of the most promising materials in radar radomes and wave-transparent antenna windows. However, the ceramic matrix surface is rather rough, which reduces their service life in severe environments. Although precision grinding is used to improve surface quality, it gets difficult to precisely achieve the desired surface requirement due to the SiO2f/SiO2 material hardness, brittleness, and complicated fiber structure, as well as the uncertain wheel conditions. Especially the wheel condition and its influence on surface quality are unable to quantify directly. With the fast development of IoT monitoring and cyber-physical system, online prediction using process physics signals gains more interest. Power monitoring is a convenient way to obtain valuable grinding information at a relatively lower cost, making it more popular in the industry. However, the links between grinding parameters, power signal, and wheel conditions, surface quality is unclear. A series of grinding experiments of the SiO2f/SiO2 workpiece has been designed to demonstrate how the wheel conditions are indicated using the warm-cold density chart of specific grinding energy. A novel exponential polynomial model of surface roughness associated with wheel conditions indicated by the cutting power signal has been built. Compared with the conventional prediction model, REs center, MSE, and Pearson correlation coefficient are improved significantly from −0.0213, 0.029669, and 0.8695 to 0.0022, 0.022478, and 0.8710, respectively.