Tread Grooves Research Articles

Numerical analysis of the tread grooves' acoustic resonances for the investigation of tyre noise

Abstract Tyre/road noise is one of the major sources of noise pollution in urban areas. This phenomenon can be described as the combined effect of several generation and amplification mechanisms. Acoustic resonances due to the tread grooves at the footprint region, also known as pipe resonances, are particularly important since they can generate high noise levels if they combine with harmonic generation mechanisms. This paper deals with a numerical investigation of this phenomenon and describes modelling approaches that might be used to estimate the frequencies and the mode shapes of these resonances.

Hydroplaning of Tires: A Review of Numerical Modeling and Novel Sensing Methods

Abstract This article represents an extensive literature on tire hydroplaning, specifically focusing on the assessment of real-time estimation methodologies and numerical modeling for both partial and total hydroplaning phenomenon. Hydroplaning still poses a significant challenge for contemporary passenger cars, even those equipped with state-of-the-art safety systems. The active safety features that equip the most technologically advanced passenger cars are unable to forecast and prevent the occurrence of hydroplaning. Total hydroplaning represents a phenomenon which occurs when the tire reaches a point where it can no longer expel the water from its tread grooves, leading to a complete control loss of the motor vehicle. This describes a scenario in which the entire contact patch is lifted from the ground due to the hydrodynamic forces generated at the contact between the tire and the layer of water formed on the road. Nevertheless, the decrease in contact between the tire and the road surface occurs gradually, a phenomenon which is presented in the literature as partial hydroplaning. The longitudinal speed that marks the transition from partial hydroplaning to total hydroplaning is defined as the critical hydroplaning speed. These principles are widely acknowledged among researchers in the hydroplaning field. Nonetheless, the literature review reveals variations for defining the critical hydroplaning speed threshold across different experimental investigations. In this article, past studies, and state-of-the-art research on tire hydroplaning has been reviewed, especially focusing on real-time estimation methodologies and numerical modeling of the partial and of the total hydroplaning phenomenon.

Water Films and Hydroplaning on Highways: Hydrodynamic Aspects

The quantification of water depths resulting from rain events on highways is presented using concepts of flows along flat plates. The hydrodynamics of the water film was developed by taking the basis of the fluid–surfaces interaction, generating equations for the depth of the films that reproduce adequately measured data considering the equilibrium between impulsive and resistive forces. To consider geometrical changes, corrective parcels were added, obtained through dimensional analysis involving the depth of the texture of the pavement. The exponents and coefficients of the formulation were adjusted to better reproduce literature data and check the adequacy of the obtained solutions. The hydroplaning phenomenon was treated using the integral formulation of the principles of conservation of mass and momentum, inserting information of the tread grooves in the control volume equations, which evidences its effect on the general hydroplaning velocity. Both the formulations (film thickness and hydroplaning) are presented in nondimensional form to allow their use with any system of units. The good correlations obtained between measurements and predictions show that the hydrodynamics of both the water films and the hydroplaning phenomenon were adequately quantified through the application of the basic physical principles. The resulting equations can help design purposes and be used in further studies on this theme.

Tread Patterns and the Effect on Basketball Player Slippage

The focus of this study was to investigate the effects that different basketball shoe outsole tread patterns have on the amount of slip and therefore the performance of the individual while undergoing normal basketball transitions. Tread grooves and patterns must exist on the outsole of a basketball shoe to account for the chances of contamination and for the practical durability of the shoes. With the existence of so many basketball shoes with varying tread patterns and characteristics it presents the question of whether or not varying patterns affect traction, slip, and athletic performance. This study evaluated the amount of slips of two pairs of basketball shoes with human participants running basketball drills on a hardwood basketball floor at Wartburg College. The results indicated that one shoe with a more unique tread pattern exhibited fewer slips and severe slips, especially when considering lateral movements, than the shoe with a tread pattern seen more often in shoes available on the market today.

An Evaluation of Shoe Tread Parameters using FEM

Within this paper, a three-dimensional finite element (FE) model of a uniformly loaded, single rubber block, is described and run using loading conditions replicative of a standard slip resistant footwear test. The FE model considers rubber hyperelastic and viscoelastic material properties, obtained using dynamic mechanical analysis. The performance of the FE model was evaluated through analytical compression analysis and experimental contact area testing. The effect of tread grooves was investigated with relation to slip-resistance during walking. Analysis and discussion are provided of the tread model's sliding contact areas, contact pressure, stress, and front edge mechanics.

Computing Tire Component Durability via Critical Plane Analysis

ABSTRACT Tire developers are responsible for designing against the possibility of crack development in each of the various components of a tire. The task requires knowledge of the fatigue behavior of each compound in the tire, as well as adequate accounting for the multiaxial stresses carried by tire materials. The analysis is illustrated here using the Endurica CL fatigue solver for the case of a 1200R20 TBR tire operating at 837 kPa under loads ranging from 66 to 170% of rated load. The fatigue behavior of the tire's materials is described from a fracture mechanical viewpoint, with care taken to specify each of the several phenomena (crack growth rate, crack precursor size, strain crystallization, fatigue threshold) that govern. The analysis of crack development is made by considering how many cycles are required to grow cracks of various potential orientations at each element of the model. The most critical plane is then identified as the plane with the shortest fatigue life. We consider each component of the tire and show that where cracks develop from precursors intrinsic to the rubber compound (sidewall, tread grooves, innerliner) the critical plane analysis provides a comprehensive view of the failure mechanics. For cases where a crack develops near a stress singularity (i.e., belt-edge separation), the critical plane analysis remains advantageous for design guidance, particularly relative to analysis approaches based upon scalar invariant theories (i.e., strain energy density) that neglect to account for crack closure effects.

Integration of localized surface geometry in fully parameterized ANCF finite elements

This paper introduces a new method for the integration of localized surface geometry with fully parameterized absolute nodal coordinate formulation (ANCF) finite elements. In this investigation, ANCF finite elements are used to create the global geometry and perform the finite element (FE)/multibody system (MBS) analysis of deformable bodies. The localized surface geometry details can be described on ANCF element surfaces without the need for mesh refinement. The localized surface is represented using a standard computational geometry method, Non-uniform rational B-spline surface (NURBS), which can describe both conic surface and freeform surface efficiently and accurately. The basic idea of the integration of localized surface geometry with ANCF elements lies in the inclusion of such detail in the element mass matrix and forces. The integration can be implemented by overlapping the localized surface geometry on the original ANCF element or by directly trimming the ANCF element domain to fit the required shape. During the integration process, a mapping between ANCF local coordinates and NURBS localized geometric parameters is used for a consistent implementation of the overlapping and trimming methods. Additionally, two numerical integration methods are compared for the rate of convergence. The results show that the proposed subdomain integration method is better, since it is optimized for dealing with complex geometry. The proposed subdomain method can be used with any fully parameterized ANCF element. In order to analyze the accuracy of the proposed method, a cantilever plate example with localized surface geometry is used, and the simulation results with the proposed method are compared with the simulation results obtained using a commercial FE code. Two other examples that include contact with ground and localized surface geometry are also provided. These examples are a simple plate structure with surface geometry and a tire with tread details. The incompressible hyperelastic Mooney–Rivlin material model is used to describe the material used in the tire tread. It is shown through the tire contact patch that the proposed method can successfully capture the effect of the tread grooves. The rate of convergence and locking of fully parameterized ANCF elements are also discussed in this paper.

Shoe Sole Tread Designs and Outcomes of Slipping and Falling on Slippery Floor Surfaces

A gait experiment was conducted under two shoe sole and three floor conditions. The shoe soles and floors were characterized by the tread and groove designs on the surface. The coefficients of friction (COF) on the floor in the target area were measured. The subjects were required to walk on a walkway and stepping on a target area covered with glycerol. The motions of the feet of the subjects were captured. Gait parameters were calculated based on the motion data. Among the 240 trials, there were 37 no-slips, 81 microslips, 45 slides, and 77 slips. It was found that the condition with shoe sole and floor had both tread grooves perpendicular to the walking direction had the highest COF, the shortest slip distance, and the lowest percentages of slide and slip. The condition with shoe sole and floor had both tread grooves parallel to the walking direction had the lowest COF and the longest slip distance among all experimental conditions. The Pearson’s correlation coefficients between slip distance and slip velocity, time to foot flat, foot angle, and compensatory step length were 0.82 (p<0.0001), 0.33 (p<0.0001), −0.54 (p<0.0001), and −0.51 (p<0.0001), respectively.

Parametric analysis of runway stone lofting mechanisms

The influence of various factors affecting the severity of runway debris lofting mechanisms was investigated by performing numerical simulations and drop-weight impact experiments to assess the likelihood of a stone impact. Geometrical characterisation of stones collected from airfields led to a generic model of a tyre rolling over stones of various shape with different overlaps, orientations, and densities. In numerical simulations of a 0.4 m diameter aircraft tyre rolling at 70 m/s, a 10 mm diameter spherical stone was lofted at a maximum vertical speed of 35 m/s. For equivalent mass prolate spheroid stones, the loft speeds were 11–34% lower depending on the stone orientation. Objects with flat surfaces exhibited different lofting mechanisms and lower angular velocities. The conditions most conducive to stone lofting were very stiff, small diameter, sharp cornered tyres rolling on ground with a high friction coefficient over spherical stones such that just under half the stone diameter was covered by the tyre. The stone loft speed was approximately proportional to the square root of the tyre tread stiffness. Finally, tyre tread grooves could throw stones upwards at the tyre-ground separation speed, which was 17 m/s for the conditions mentioned earlier.

Reduction of Pipe Resonances in Tire Tread Grooves an Drainage Asphalt Pavement

Reduction of Pipe Resonances in Tire Tread Grooves an Drainage Asphalt Pavement

Relationship Between Measured Friction Coefficients and Two Tread Groove Design Parameters for Footwear Pads

The shoe sole geometrical design parameters are believed to be important factors affecting the coefficient of friction (COF) between the shoe/floor interface. This study is concerned with the relationship between the measured COF and the tread groove orientation and width on the footwear pad. Friction measurements using the Brungraber Mark II slipmeter were conducted. Six tread groove width/orientations designs on the footwear pads under 27 footwear material/floor/contamination conditions were tested. The results show that tread orientation and width affect the measured COF significantly. Wider grooved footwear pads result in higher COF values and footwear pads with tread grooves perpendicular to the friction measurement direction have higher COF values. A regression model using measured COF as the dependent variable and tread groove width, groove orientation, footwear material, floor, and contamination conditions as independent variables was established. The models are significant at p<0.0001 with R 2 of 0.97, which may be used in predicting the COF at the shoe-floor interface.

The effect of shoe sole tread groove depth on the friction coefficient with different tread groove widths, floors and contaminants

Slipping and falling are common phenomena in both workplaces and our daily activities. The risks associated with slipping and falling are related to the materials of footwear/floor, contamination condition, and geometric design of the sole. Shoe soles of various tread design are very common. Tread pattern of the shoe affects friction especially under liquid-contaminated conditions. Verification of the effects of tread groove depth is significant in assisting designers in designing proper footwear for workers exposed to slippery floor conditions. In this study, we measured the friction coefficients using the Neolite footwear pads on the terrazzo, steel, and vinyl floors under three liquid-contaminated conditions. A Brungraber Mark II slipmeter was used. The footwear pads had tread grooves with a width of either 3 or 9 mm. The depth of the tread grooves ranged from 1 to 5 mm. The results showed that tread groove depth affected the friction coefficients significantly. Higher friction values were recorded for footwear pads with deeper tread grooves on wet and water–detergent-contaminated floors. The averaged coefficient of friction (COF) gain per tread groove depth increase in millimeter under these two surface conditions ranged from 0.018 to 0.108, depending on the tread groove width, floor, and contaminant.

Measurement of Floor Slipperiness Using Footwear Pads with Various Tread Groove Width Design

Measurement of the coefficient of friction (COF) between the shoe/sole and the floor is essential in understanding the risk of slipping accidents. COF measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of people's daily experiences because tread groove design on footwear is very common. This research investigates the effects of the tread groove width on the measured COF. The results indicated that tread groove width significantly (p＜0.0001) affect COF under various footwear material, floor, and contamination conditions. Wider tread grooves resulted in higher COF values with a few exceptions especially on oil contaminated floor. Stepwise regression was performed to establish a linear regression model between COF and the tread groove width under footwear material/floor/liquid-contamination conditions. A seven-independent-variable model with an adjusted R^2 of 0.74 was obtained. The lack of fit test result for the model was significant at p＜0.0001, indicating that the model adequately fit the friction measurement data.

Effects of tread groove orientation and width of the footwear pads on measured friction coefficients

The shoe sole geometrical design parameters, such as tread groove orientation and groove width, were believed to be important factors affecting the COF between the shoe/floor interface. In this study, friction measurements using a Brungraber Mark II slipmeter were conducted under three footwear materials, three floors, and three contamination conditions. Six tread groove designs (2 widths × 3 orientations) on the footwear pads were tested. The results showed that all the footwear materials, floors, and the contamination conditions affected the measured COF significantly. In addition, the tread groove orientation and width also affected the COF significantly. It was found that wider grooved footwear pads resulted in higher COF values and footwear pads with tread grooves perpendicular to the friction measurement direction had higher COF values. A linear regression model using COF as the dependent variable and tread groove width, tread groove orientation, footwear material, floor, and contaminated conditions as independent variables was established. The lack of fit test result for the model was significant at p < 0.0001, indicating that the model adequately fit the friction measurement data.

MEASUREMENT OF FLOOR SLIPPERINESS USING FOOTWEAR PADS WITH VARIOUS TREAD GROOVE WIDTH DESIGN

ABSTRACT Measurement of the coefficient of friction (COF) between the shoe/sole and the floor is essential in understanding the risk of slipping accidents. COF measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of people's daily experiences because tread groove design on footwear is very common. This research investigates the effects of the tread groove width on the measured COF. The results indicated that tread groove width significantly (p<0.0001) affect COF under various footwear material, floor, and contamination conditions. Wider tread grooves resulted in higher COF values with a few exceptions especially on oil contaminated floor. Stepwise regression was performed to establish a linear regression model between COF and the tread groove width under footwear material/floor/liquid-contamination conditions. A seven-independent-variable model with an adjusted R 2 of 0.74 was obtained. The lack of fit test result for the model was significant at p<0.0001, indicating that the model adequately fit the friction measurement data.

The effect of shoe soling tread groove width on the coefficient of friction with different sole materials, floors, and contaminants

Tread groove design is very common in footwear. However, coefficient of friction (COF) measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of the footwear pad. This research investigates the effects of the tread groove width on the measured COF using four footwear materials, three floors, and four liquid-contamination conditions using a Brungraber Mark II slipmeter. The analysis of variance results indicated that the footwear material, floor, contamination conditions, and groove width were all significant (p<0.0001) factors affecting the measured COF. The hypothesis that wider tread grooves result in higher COF values was true with some exceptions especially on oil contaminated floors. A regression model, with an R2 of 0.91, was established to describe and predict the relationship between the COF and the tread groove width under footwear material/floor/contamination conditions.

Pilot studies to evaluate the efficacy of a truck-mounted tire sanitizer system

Objective: To determine whether using a tire sanitizer system to apply a disinfectant or water would reduce or eliminate bacteria on the tires of a truck after it was driven through a swine farm. Materials and methods: After truck tires were contaminated by driving on a farm road in the spring and fall, disinfectant or water was sprayed on the left tires using a tire sanitizer system. The right tires were untreated controls. Bacterial counts were compared from swabs collected from standard areas of the tire after contamination and after treatment. Results: Use of the tire sanitizer system with disinfectant was effective in removing bacteria from the tire footprint and, in most cases, the tread grooves of tires in fall and spring seasons. Use of the tire sanitizer system to spray water was not effective in reducing bacterial counts. Driving along an asphalt road, without use of disinfectant, removed bacteria from tires in some cases. In cool, muddy conditions, bacterial counts on the tires were lower when the tire sanitizer system was used than when the system was not used, but counts were not consistently lower in warm, dry conditions. Implications: Bacterial numbers on tires varied with temperature and moisture conditions. Use of the tire sanitizer system with disinfectant was effective in removing bacteria from the footprints and, in most cases, from the tread grooves. Use of tire sanitizers with disinfectant may be an adjunct tool in protocols for vehicle decontamination.

The structure of the cultivated horizon of a Stagnogleyic Luvisol developed from loam, within the zone affected by tractor wheel traffic

An analysis of the structure and physical properties was performed for a Stagnogleyic Luvisol developed from boulder clay and compacted by the front and rear wheels of a U-1212 tractor in the course of spring tillage. It was found that as a result of the compaction the structure of the soil was transformed from aggregated to non-aggregated. The rear wheel deformed the soil more strongly than the front wheel, the greatest compaction occurring in the soil mass pressed into the tyre tread grooves. Consequently, the greatest deterioration in the aeration properties of the soil was observed in that zone.

Finite Element Simulation of Destructive Tire Testing

Abstract Three destructive tire tests, burst pressure, high speed free rotation, and DOT plunger energy are performed to check the ultimate strength of new tires. These tests represent some of the extreme, although unusual, overload conditions that may be applied to a tire. They are used to determine how far above normal service conditions one might take a tire before it reaches its ultimate strength. A nonlinear incompressible rubber model and a nonlinear cord-rubber composite model were used in the tire analyses. Various rubber compounds as well as the rubber in the cord-rubber composite were modeled as nonlinear incompressible Mooney-Rivlin materials. The bimodulus cord and the cord angle change effect due to deformation were also considered. In addition, gap elements were used at the tire-rim interface and between tread grooves where required to provide appropriate boundary conditions. Numerical simulations of these destructive tire tests represent three excellent benchmarks to verify and to evaluate the robustness of a finite element code due to very large strain and deformation occurring in the tire. The numerical results predicted by the finite element tire models agreed very well with the available experimental data.

Residual stresses in the surface layer of tread grooves in bolts formed from titanium alloy VT16

Residual stresses in the surface layer of tread grooves in bolts formed from titanium alloy VT16