Wheel Disc Research Articles

Simulation of vehicle tires based on the finite element method

Modeling of wheeled vehicles is one of the main directions of development and practical application of software systems based on modeling the dynamics of body systems. In this paper, a technique for analyzing a vehicle tire by the finite element method under various types of loading is considered in order to identify the parameters of its simplified dynamic models. Based on the finite element method, a refined tire model is created. It takes into account the complex geometric shape of various tire parts, their material properties, as well as the contact interaction of the tire with the support. The efficiency of this model was tested, both when performing static calculations of the stress-strain state of the tire from the action of an external load, and when solving the generalized eigenvalue problem. The great influence of external load on the natural frequencies and vibration modes of the tire is confirmed. One of the possible applications of the considered method of finite element modeling of a tire is the performance of refined calculations of the dynamics of wheeled vehicles in the “Universal Mechanism” software package. There are several variants of dynamic tire models that can be used to study the dynamics of off-road wheeled vehicles, including a model based on the method of discrete elements and a model based on the method of coupled substructures. A model based on the method of discrete elements represents a number of absolutely solid bodies-particles, connected to each other and by a wheel disk by a set of elastic-dissipative elements. Each particle of this model has three linear degrees of freedom relative to the wheel disk. The results of calculations of the refined finite element model of the tire are necessary to identify the mass and elastic-dissipative properties of this dynamic tire model. In the model based on the method of connected substructures, the elastic displacements of the tire are represented as the sum of the admissible shapes of the elastic body. Static and natural vibration modes are used as permissible forms of an elastic body, calculated using a refined finite element model of the tire.

The simulation of crack growth in rolling stock running wheel disk

The article reviews scientific and technical literature in the field of the survivability of railway wheels. The computer simulation of the flat crack growth at different temperatures is performed with the estimation of the crack propagation rate and survivability parameters. In conclusion, the estimation is provided to refine the calculation model, followed by the recalculation of the obtained results.

Investigation on automobile wheel rim aluminium 6061 and 6066 Alloys using ANSYS WORKBENCH

The essential of car wheel rim is to provide a firm base on which to fit the tyre. Its dimensions, shape should be suitable to adequately accommodate the particular tyre required for the vehicle. In this project a tyre of car wheel rim belonging to the disc wheel category is considered. The wheel rim is model by using SOLIDWORKS 2016. By using this software, the risk involved in the design and manufacturing process can be easily minimized. So the modeling of the wheel rim is made by using SOLIDWORKS. Later this wheel rim modal is imported to ANSYS WORKBENCH 16 for analysis work. ANSYS WORKBENCH 16 is the latest software used for simulating and also calculating the different properties and viewing the results. ANSYS WORKBENCH 16 static structural analysis work is carried out by considering four different aluminium alloys namely 6061 and 6066, their relative performances have been observed respectively. In addition to wheel rim is subjected to modal analysis, part of dynamic analysis is carried out its performance is observed. In this analysis by observing the results of both static and dynamic analysis obtained best material is suggested for making an effective rim structure.

Microleakage difference between total-etch and self-etch bonding in bulk fill packable composite restoration after carbonic acid immersion

Background: Bulk fill packable composite that can be applied to a depth of 4mm in cavities is widely used in posterior teeth restoration. Unfortunately, this composite is subject to potential microleakage which occurs due to erosion resulting from the consumption of carbonated drinks containing carbonic acid. Nevertheless, microleakage can be reduced by bonding applications the etch technique of which is divided into two forms; self-etch bonding and total-etch bonding. Purpose: This study aims to determine the difference in microleakage between total-etch and self-etch bonding in bulk fill packable composite following carbonic acid immersion. Methods: This study constitutes experimental laboratory research utilizing 28 incisors bovine teeth which were cleaned, immersed in 0.01% NaCl, and randomly divided into four groups. The cervical area of the teeth of all groups were prepared through the creation of cylindrical shapes 2mm in diameter and 3 mm deep. Groups I and III used total-etch bonding, while groups II and IV used self-etch bonding. Groups III and IV were control groups, whereas groups I and II were treatment groups (immersed in carbonic acid) for 24 hours. Thermocycling was carried out in all groups which were subsequently immersed in 1% methylene blue for 24 hours after which the teeth were cut in a buccolingual direction using a diamond disc wheel. Microleakage was subsequently evaluated by calculating the amount of methylene blue passing between the restoration wall and cavity using a Stereomicroscope and scanning electron microscope (SEM). The data was then analyzed using Kruskal Wallis and Mann Whitney U tests. Results: There was a significant difference between the control groups and treatment groups (p<0.05). The microleakage in Group 2 was higher than that of other groups. Conclusion: The microleakage of total-etch bonding was lower than self-etch bonding in bulk fill packable composite after carbonic acid immersion.

TRENDS FOR THE PROVISION OF SURVIVAL OF WHEELS OF MILITARY CAR EQUIPMENT

The article analyzes the viability of military vehicles from the effects of conventional damage (bullets, splinters), etc. When fired, a car that stops for a short time becomes an easy target and is destroyed. The presence of a tire pressure control system on the vehicles substantially increases the possibility of continued traffic. However, the opportunities of the mobility adjustment system is limited. The required survivability can only be ensured if special wheels are used. RunFlat (flat tire) is the common name for tireless tire technology. The RunFlat car wheel inserts allow you to continue driving after a tire has been punctured or descended, which can, for example, allow the machine to exit the firing zone. The essence of technology is to strengthen the sidewalls of tires. Hutchinson produces wheel inserts of two types - RODGARD and CRF. The RODGARD RunFlat (Rotary RunFlat) system is capable of providing deflated tires thanks to a special patented design. The CRF RunFlat (Static RunFlat) system is a wheel insert that is used as a single unit of the center of the wheel and tubeless tire. Сommon CSR (Conti Support Ring) system includes a metal ring that is fastened to the rim. The disadvantage of this system is that the support ring will only fit in the high profile wheels. The first cars wish RunFlat in the Armed Forces of Ukraine were KrAZ Cougar and Spartan cars. In turn, the main disadvantages of using wheels with RunFlat include, in addition to the much higher cost, the inability to use the tire after long distances. Airless tire (non-pneumatic) is an innovative development that is a one-piece wheel that can replace both the wheel disk and the pneumatic tire.The main advantage of this design is that the wheel does not require pumping, is not afraid of punctures, is resistant to damage and has a long service life. In this case, the weight of the wheel is almost twice as light, the life of such a wheel is two to three times longer, but the cost is more than twice the price of standard wheels. It is proved that the grip of the road surface in such tires is not inferior to traditional tires, and rolling resistance has decreased to hundreds. The Polaris Defense non-pneumatic wheels guarantee significantly better durability than standard tires and can withstand a 12.7mm bullet. The disadvantage of using non-pneumatic (airless) wheels is to create additional load on the suspension of the car due to their rigidity.

Investigation of Heat Transfer Characteristics on Rod Fastening Rotor

In order to study the contact heat transfer characteristics on the joint interface of the distributed rod fastening rotor under the influence of different pretension and the roughness of different wheel disk. The thermal contact resistance fractal model on the joint interface of the distributed rod fastening rotor is established, and the thermodynamic calculation of the rod fastening rotor is carried out. A contact heat transfer characteristic test rig for the rod fastening rotor is designed and built. The temperature field of the rod rotor is measured with the change of the tension force of the pull rod and the surface roughness of the wheel. The results show that the heat transfer coefficient of the joint interface increases with the increase of the pretension of the rod, and decreases with the increase of the surface roughness of the wheel. The thermal contact resistance fractal model of the joint interface is verified, and it is proved that it is suitable for the study of the thermal contact resistance on joint interfaces.

Grinding Deviation Analysis of Offset Face Gear Based on Involute Disc Wheel

Offset face gear drive has shown many unique advantages in the area of crossed-axes transmission. In this paper, deviation analysis of an offset face gear using a involute disc wheel as a cutting tool has been discussed to achieve precised machining.Firstly, equations of involute disc wheel and offset face gear are derived based on meshing theory.Then, a grinding machine tool is designed and equations of offset face gear containing machining deviation are derived.At last,figures of deviation cloud of face gear surface are created with MATLAB and importance of different machining deviation is discussed.The results show that the deviation Az along the axis of grinding wheel is the most influential deviation,while Ay along the axis of face gear is the least one.

A grinding method of face gear mating with a conical spur involute pinion

A grinding method of face gear manufactured by a disk wheel is proposed in this paper. The computerized generation of the face gear by application of a conical spur involute shaper is presented. The tooth surfaces of the face gear are ground point by point with the disk wheel. In addition, a numerical model for determination of envelope residuals of the ground face gear surfaces is established. This model is used to determine the grinding tracks of the disk wheel according to the prescribed processing precision. The manufacture of four different cases of face gears is simulated by applying a simulation platform to illustrate the effectiveness of the proposed grinding method. The results show that deviations of excess greater than the prescribed processing precision only exist on the fillet surfaces and the root of the ground tooth, and increase from the fillet surfaces to the mean section of the root of the face gear. However, this has no influence on the meshing of the face gear drive. The processing efficiency of the face gear grinding is sufficiently affected by the prescribed processing precision.

Computational fluid dynamics analysis of hand-cycle aerodynamics with static wheels: Sensitivity analyses and impact of wheel selection

Aerodynamics research in cycling has underpinned innovative bicycle design, new refined riding positions and optimised rider apparel. There has been a rise in the level of aerodynamics research focused on cycling since the turn of the millennium, enabled by significant increases in computational power and the availability of software/hardware. However, cycling research has not yet fully embraced para-cycling, with limited studies conducted on the aerodynamic performance of hand-cyclists and other para-cyclists. Wind tunnel experiments and computational fluid dynamics simulations were conducted in this research for the analysis of hand-cycling aerodynamics, focused on competitive H1–H4 category hand-cyclists. A quarter-scale representative geometry of a hand-cyclist was used in high-speed wind tunnel experiments. The accuracy of the simulations performed with the three-dimensional Reynolds-averaged Navier–Stokes equations was found to be dependent on the turbulence model choice and near-wall grid resolution. Computational fluid dynamics simulations predicted the magnitude of the drag and lateral forces to an accuracy of 2.5% using the shear stress transport [Formula: see text] turbulence model. This study also presents the impact of wheel diameter and disc wheels on hand-cycling aerodynamics via computational fluid dynamics simulations, providing a deeper understanding of the aerodynamic characteristics unique to the hand-cycling discipline in the sport of competitive cycling. Drag reductions of up to 8.9% were found when utilising 20-inch diameter spoked wheels, opposed to the 26-inch wheels. Variations in wheel diameter between the front and rear wheels were found to have a significant impact on the CDA in part through altering the pitch angle of the hand-cycle.

Surface residual stress distribution for face gear under grinding with a long-radius disk wheel

Face gear transmission has been widely used because of its unique technical advantages. The residual stress of a tooth surface after grinding is the key factor affecting the surface quality of gear teeth. To improve the performance of tooth surfaces and better guide the grinding test, it is necessary to develop a method to analyse the residual stress of face gear after grinding with a long-radius disk wheel. First, a mathematical model of the grinding face gear with a long-radius disk wheel is established. Then, the basic parameters affecting face gear grinding are studied, and mathematical calculation models, including the grinding force and grinding heat, are established. On this basis, the three processes of elastic loading, plastic deformation and stress release are studied, and a mathematical model of the residual stress of face gear grinding is established. Finally, face gear grinding tests are carried out; the residual stress is determined, and the model is verified by experimental data. Through the study of the surface residual stress distribution of face gear under grinding with a long-radius disk wheel, the grinding process can be further guided to improve the grinding quality and can be extended to the analysis of residual stress distribution after grinding of other complex surface parts.

Analysis and multi-objective optimization design of wheel based on aerodynamic performance

In the past studies, the influence of wheel structure design and optimization on the aerodynamic drag of car and heat transfer performance of brake disc was less studied. To study the influence mechanism, the finite element model for wheel aerodynamic analysis was established using computational fluid dynamic method and the correctness of the model was verified by the wind tunnel test data. The influence mechanism of the flow field on aerodynamic drag of car and wheel and heat transfer performance of brake disc was studied. The influence of wheel disc structure on aerodynamic drag coefficient of the car and average convective heat transfer coefficient of the brake discs was studied. The parametric model of the wheel under the computational fluid dynamic analysis was established using mesh morphing technology. A total of 100 and 10 sample points were extracted using the Hammersley Design and Optimal Latin Hypercube Design, respectively, to fit the radial basis function surrogate model and test the accuracy of the surrogate model. Based on the established surrogate model, taking the minimum of the wheel mass, the minimum of the aerodynamic drag coefficient of the car and the maximum of the average surface convective heat transfer coefficient of brake discs as objectives and design variables of wheel as constraints to ensure the wheel structural strength, the non-dominated sorting genetic algorithm was adopted to carry out multi-objective optimization design for the wheel. Pareto frontier was obtained and a compromise solution was selected as the optimization design result. After the optimization design, the wheel mass is reduced by 8.28%, the aerodynamic drag coefficient of the car is reduced by 3.17% and the average surface convective heat transfer coefficient of brake discs is increased by 9.31%.

Vibration characteristics analysis of a stepped-shaft-flexible-disk coupling system

Disk-like structures have large stiffness for the subaerial rotating machine, which are commonly assumed as lumped-mass points for the traditional rotor dynamic analysis. In order to reduce the weight in aero engine, the wheel disk is relatively thin and flexible for which their flexibility cannot be ignored. At present, there are few researches on the vibration characteristics of the rotating-shaft-flexible-disk coupling system. In order to make up for the deficiency of the present research, this paper combines the assumed mode method with the finite element (FE) method, and adopts the FE-semi-analytical method to establish the dynamic model of stepped-shaft-flexible-disk coupling system. In the proposed model, the stepped shaft was simulated by Timoshenko beam, and the flexible disks were modeled using semi-analytical method. The Lagrange equation and the Galerkin method are used to derive the differential equations of motion of the system. The natural frequencies of the system are calculated under stationary and rotating conditions, and ANSYS software simulations and experiments are used to verify the proposed model. Finally, the frequency-responses are compared under the assumptions of rigid and flexible disks, respectively. The effects of flexible disk on the high-order vibration of the system are revealed.

Cracking phenomena in automotive wheels: An insight

In an automotive, wheels form a very critical and important part with respect to application. Wheels with as less number of flaws as possible are a must to make them fit for application in field. The norms of wheel quality parameters are becoming stringent day by day, thereby increasing the onus on raw material suppliers i.e. – steelmakers to improve the soundness of sheet steel. During their manufacturing (through cold forming, welding etc. of hot rolled sheets) cracking of wheel rim or disc is a major issue encountered at the production line. Surface crack, bore crack and flange crack are common types of failures which lead to rejection. This paper discusses a compilation of metallurgical studies of various such defects and their probable root causes, as conducted by authors. Metallography and advanced characterization techniques have been used in analysing the root cause of the defects. Presence of non-metallic foreign material in steel is one of the major causes leading to surface cracks in wheels. In some cases, it has been found that segregation of elements like Carbon, Phosphorous in steel sheets can lead to poor performance of material during deep drawing or forming at the wheel-maker's end. There are also evidences that bad shearing process at the wheel maker's end can also initiate cracking in wheel.

Effects of full-stops on shoe-braked railway wheel wear damage

The purpose of this work is to gain a better understanding of the complex damage phenomena taking place at the railway wheel/brake block interface due to thermo-mechanical loading. Initially, full-stop braking was studied using Finite Element (FE) simulations to estimate the temperature reached in the wheel rim. Experiments to reproduce wheel damage were conducted with a two-disc machine using test conditions that were based on the results of the FE simulations. Three different wheel steels were tested against the same cast iron shoe material. The evolution of the wheel disc damage was studied at various numbers of cycles under fixed contact pressure and sliding speed. The friction coefficient and the temperature on the wheel disc surface were measured during the tests. At the end of the experiments, the wheel disc was examined and characterized. Cross-sections were observed with an optical microscope and the hardness was measured as a function of the depth to investigate the damage mechanisms that occurred at surface and subsurface. Material transfer from the shoe specimen to the wheel specimen results in the formation of a discontinuous “third body” layer, and that layer plays a key role in the evolution of the wheel disc damage. When the transferred layer of brake material is worn away, detachment of steel from the wheel disc surface occurs, probably promoting the crack nucleation. In addition, wear debris from both disc materials promotes three-body abrasive wear of the wheel disc surface.

Influence of truck tires exploid on the level of professional risk in servicing truck wheel

The article deals with a problem of minimization of levels of professional risks while servicing truck tires and wheels. In the process of removal of a truck wheel a worker can sustain a serious or fatal injury caused by the explosion of an inflated truck tire. The explosion of an inflated truck tire can result in affecting of complementary offloading’s on clamps cast spoke wheel. The mathematical model description of move of a disk wheel and values of reactive forces arising from the explosion of an inflated truck tire are presented. The equations of move of a disk wheel at its removal under the influence of reactive forces are solved. Results of numerical modelling of stresses arising on clamps cast spoke wheel during the explosion of the inflated truck tire are presented. The maximum normal stress arises in the stub basis can lead to free move of wheel and in a place of contact of a disk of a wheel high tangential stresses to destruction of a nut is positioned.

Establishment and Verification of the Cutting Grinding Force Model for the Disc Wheel Based on Piezoelectric Sensors.

In this paper, a new model of cutting grinding force for disc wheels is presented. Initially, it was proposed that the grinding cutting force was formed by the grinding force and cutting force in combination. Considering the single-grit morphology, the single-grit average grinding depth, the effective number of grits, and the contact arc length between the grit and the workpiece comprehensively, the grinding force model and the cutting force model were established, respectively. Then, a universal grinding cutting force model was optimized by introducing the effective grit coefficient model, dependent on the probability statistical method and the grit height coefficient model with Rayleigh’s distribution theory. Finally, according to the different proportions of the grinding force and cutting force, the grinding cutting force model, with multi-particles, was established. Simulation and experimental results based on piezoelectric sensors showed that the proposed model could predict the intermittent grinding cutting force well. Moreover, the inclusion of the grit height coefficient and the effective grits number coefficient improved the modeling accuracy. The error between the simulation and experimental findings in grinding cutting force was reduced to 7.8% in comparison with the traditional model. In addition, the grinding cutting force can be divided into three segments; increasing, steadiness, and decreasing, respectively found through modeling.

Aerodynamics analysis of wheel configurations in Paralympic hand-cycling: A computational study

Abstract Para-cycling aerodynamics holds additional complexities compared to its able-bodied counterpart. Hand-cycling provides such an example, where three wheels opposed to the two wheels of a traditional bicycle are required. Wheel aerodynamics are therefore even more prevalent in the field of Paralympic hand-cycling. However, there has been little attention devoted to wheel aerodynamics in Paralympic hand-cycling. This study investigates hand-cycling wheel aerodynamics. The optimal wheel selection was investigated from a combination of wheels that represented competitive deep-section spoked wheels and disk wheels. In addition to the various wheel combinations, the spacing between the two rear wheels was varied. A 55 cm rear wheel spacing provided drag reductions of up to 4.7% compared to 70 cm when using rear disk wheels at 0°yaw. Crosswinds were also investigated, and it was shown that a front disk wheel coupled with rear deep-section wheels at 55 cm spacing provided the best aerodynamic drag performance with increasing yaw angle. With this wheel setup, the C D A increased by only 7.7%, between min and max values found at 0°and 15°yaw respectively.

ПАРАМЕТРИЧНИЙ ПІДХІД ДО МОДЕЛЮВАННЯ ДИСКА АВТОМОБІЛЬНОГО КОЛЕСА

The paper considers the issue of constructing a parametric computer model of a car wheel disk in Autodesk Inventor. The constructed model of a car disk allowed to obtain a wide range of various geometric solutions. The proposed algorithm for constructing a disk model made it possible, by varying several parameters, to substantially change the geometry of the guide of each individual spoke — from the straight line to the Archimedes spiral, the involute of the circle, and all the intermediate curves. The results are obtained for cases when the spokes have a square, rectangular (flat), trapezoidal, triangular geometry with or without rounding, as well as a circle shape. This was achieved within the framework of one parametric three-dimensional model due to a change in the values of the corresponding parameters. It should be noted that the model of the car was built not in art design program, but in mechanical design program. At the same time, the geometry of a large number of similar products, current trends and possible design decisions were taken into account. Thanks to the parameterization, the model allows you to quickly visually evaluate many options for geometric solutions, their pros and cons, and analyze the selected compositional solution. This is especially important if you consider that industrial designers usually do not use the modern apparatus of three-dimensional parametric modeling when working out various options for the geometry of a particular product. The constructed model of a car disk can be easily used for aerodynamic, strength and other calculations. The paper gives an example of the application of the obtained model in the design of various chair options for people with limited mobility with problems of the musculoskeletal system.

Study of the damage induced by thermomechanical load in ER7 tread braked railway wheels

This work aims to better understand the complex damage phenomena taking place at the wheel/brake block interface due to the thermomechanical load. An experimental procedure, articulated in three series of tests carried out with a bi-disc machine, was designed in order to experimentally simulate in controlled laboratory conditions the thermomechanical history of the real wheel during stop braking. The first series of tests was performed on ER7 wheel steel discs paired with cast iron shoe material discs, setting the sliding speed and the contact load in such a way to generate the heat flux needed to reproduce the typical tread temperature of a real wheel in stop braking. The second series was carried out by repeating the tests in the conditions of the first series and subsequently subjecting the tested wheel specimens to rolling/sliding contact with discs of 350HT rail steel. The third series was carried out by repeating the two phases of the second series and subsequently adding water to the contact interface of the wheel-rail specimens. Measurements of friction coefficient, surface temperature and weight changes were carried out during the tests. At the end, cross-sections of the specimens were observed with an optical microscope. The hardness along the depth was measured. It was observed that during the braking phase parts of the wheel specimen surface are coated by a discontinuous layer of cast iron that is transferred from the brake block specimens. During the braking phase and the subsequent phase of dry contact with the rail specimen, the transferred material is removed, promoting the nucleation of surface cracks; in addition, surface cracks are generated also by ratcheting due to high friction. During the subsequent wet contact phase, these cracks propagate in the wheel disc due to the pressurization of the fluid entrapped inside the cracks. The propagation of surface cracks in wet contact was assessed by a fracture mechanics approach, including the Finite Element simulation of a surface crack with entrapped fluid. The stress intensity factor range during a load pass was calculated and compared with the propagation threshold of the ER7 steel, determining this way the critical depth of surface cracks. This study is a step towards a damage tolerant approach for the designing and maintaining tread-braked wheels.

Influence of rotor–stator component partition structure on the aerodynamic performance of centrifugal compressors

ABSTRACTThe partition structure (PS) between the impeller and stationary blade of a centrifugal compressor considerably influences a compressor's performance. Based on computational fluid dynamics, this study constructed a coupling calculation model for the main flow, wheel cover, wheel disk side partition clearance, and sealing structure. Furthermore, we examined the influence that different PS shapes (i.e. circular arc, trapezoidal, and rectangular) and radial clearances (2, 4, and 6 mm) at the entrance of the cavity between the rotor and stator components have on the aerodynamic performance and loss mechanism of the centrifugal compressor using a numerical method. The influence that the PS has on the transition zone between the impeller outlet and stator inlet sections was analysed in detail. According to the results, when the PS was in a circular arc form, with a clearance of 2 mm, it achieved the highest efficiency, which increased the efficiency of the original model by 0.99% and the total pressure ratio by 1.23%. Moreover, an examination of the main flow interaction provided an enhanced insight into the microflow phenomenon in centrifugal compressors.