The first part of this paper presents the results of experimental estimation of the contact patch area depending on the normal wheel load and inflation pressure for. Pacejka, in tire and vehicle dynamics third edition, 2012. Tread radius is the curvature of the tread, shoulder to shoulder. Contact patch for tires archive mbf motorcycle forums. You buy new and larger tires and possibly wheels for your jeep and you wonder whats the proper pressure. Town fair tire tire contact patch also known as tire footprint. Dave reads the tire wear of several street bikes, explains the malady causing the wear, and the remedy necessary to restore tire health, which ultimately extends tire life which invigorates bank balance stamina. A short and wide tire contact patch, which is usually found on low profile or performance tires, can provide you with more control, corner stability and tire traction. Next to the friction coefficient between tire and road, these forces. Inflation and pressure plays a huge role on the contact patch of tires. The influence of tyre contact patch and on the stopping. A highperformance tire for enhanced traction in severe winter driving conditions the eagle ultra grip gw3 offers outstanding control and response in winter driving conditions.
Spin, longitudinal and side slip, the width effect. The tire contact patch where the rubber meets the road. In fact, a typical tire contact patch is about the size of your hand. If the car creates any aerodynamic lift, then the vertical load on the tire will be less than the weight on the tire, since the car is lifting instead of being pushed down. The difference got me to thinking about how the front tire contacts the ground, though. Contact patch picture yourself driving along the highway, just slightly over the limit, well, more than a little and the sports news comes on the radio. A graph showing the resulting profile appears in figure 3 for a tyre of unloaded radius 0. Tires with a higher profile or aspect ratio that is, the height of the sidewall is fairly large compared to the width of the tire, tend to have a long and narrow contact patch. The influence of the vertical load and of air pressure from the tire against contact patch area in the figure 6 is the variation of the total contact patch area, according to vertical load and air pressure from the tire. Additionally, the calculated contact patch pressure rises from 6. A tires contact patch is the area of the tire that comes in contact with the ground, much like a footprint. Mundl 2003 evaluation of tire tread and body interactions in the contact patch. Analysis of vehicle static steering torque based on tireroad. Tire, finite element modeling, footprint phenomena, contact patch.
It is commonly used in the discussion of pneumatic i. The paper discusses the first three phases of the project. The contact patch of most tires is about the size of your hand and has to handle a lot more weight and force than those big reeboks do. Line up the paper on the floor, taping it down will keep it from moving or sticking to the tire.
The tire contact patch all vehicles are supported by a cushion of air contained in four flexible rubber tires. The contact patch is fairly small for a large rv, with each patch being about the size of half of a sheet of paper. As a result, not much of the tires surface area is touching the ground. With the tire at 35 psi paint two to three rows of tread. Advanced tensile technology helps to improve the strength of the belt package. So for the same tire drop of 6% the 29 wheel has a 2. Hudson research report number 11902f research project 388891190 tire contact pressure distributions. The vertical load on a moving tire was estimated by using accelerometers attached to the inner liner of a tire. A laboratory study was conducted to measure vertical tire contact pressures to obtain a. Characterize the contact stresses as a function of wheel type, wheel load, and inflation pressure. Griptester fitted with both tires at a range of tire inflation pressures and for a. Believe it or not, most tires have a fairly small contact patch a little larger than the size of your hand. Your guide to tire specs, sizing, industry code information and more. This is part 6 of my 10 part series on how race car tirestyres work.
With respect to tire shape, the area of interest is the crown region and the dimensions of tread width and tread radius, figure 15. If it turns more like an automobile, then there would be a larger contact patch good for braking. Tire contact patch lowering pressure gain traction. Vertical load is the load actually seen at the tire contact patch. The contact patch of a tyre is the section of the tyres tread that is in physical contact with the road surface. Jul 02, 2016 this is part 6 of my 10 part series on how race car tirestyres work. Contact patch data was related to insitu measurement of wet grip measured using. The width of the contact patch has a considerable effect on the torque and indirectly on the side force because of the consumption of some of the friction by the longitudinal forces involved. This includes the weight resting on the tire contact patch plus any aerodynamic downforce.
Since the wear characteristics of tires is a highly competitive area. The vehicle can only put its own weight on the tire. Jan 25, 2014 the tire contact patch all vehicles are supported by a cushion of air contained in four flexible rubber tires. This paper discusses the application of noncontact methods to analyze the tire surface contact interaction. The movement of tire can be divided into two processes in static steering.
Examine stress distributions across the tire contact patch. Hudson research report number 11902f research project 388891190 tire contact pressure. The contact patch is the only connection between the road and the vehicle. Specially designed sipe channels in the tread wick water vertically into the sipes, where it is then drained into larger grooves. If the wheel turns much like a motorcycle wheel, then it seems like the tire would be riding on its edge. Evaluation of tire tread and body interactions in the. Figure 6 shows the tyre contact size against tyre pressure from 0. Contact patch length and normal load using intelligent tires and its application in. In this paper, we focus on the effect of contact patch restriction, which influences. Contact patch is the portion of a vehicles tire that is in actual contact with the road surface. The maximum width of the contact patch or footprint is determined by the tires tread width.
It is most commonly used in the discussion of pneumatic tires, i. The shape of a tire s contact patch or footprint greatly influences its performance and is dependent on its profile or aspect ratio. The higher the inflation pressure, the smaller the contact patch of tires becomes. Small ground robot to estimate the tireroad friction, tire science and. Its often different than the stock tires since the larger tires are likely a different weight rating and constructed a bit different. This paper summarizes the findings of a scaled laboratory experiment to look at what happens in the first few contact patches as a landing aircraft tire makes contact with a runway surface. To measure the contact patch of the tyre, a prescale film of fujiflim is used. Given this alone, the contact patch area should be constant for a given tire pressure and load. Then an appropriate equation relating the patch length to the vertical load is used to calculate the load. Bridgestone develops tires that result in the maximum performance of vehicles by using ultimat eye, its unique technology to visualize the contact patch. Infinicoil belt technology optimizes the shape of the contact patch for longer tread life and strengthens the crown against shocks and impacts. Tire vibration has complex behavior due to tire contact with the road and rolling. Measurement of the tire dynamic transfer stiffness at.
Getting a grip examining the elements of tire traction. The application listed below is a general reference, therefore, tire approval status shall be con. Town fair tire tire contact patch also known as tire. Tireseasy december 10, 2012 tire safety, tire technology. Longer and narrower tire contact patches are most often found on passenger vehicles. Tire contact patch characterization through finite element.
The contact patch will vary in shape and size depending on the geometry of the tire, and this affects various performance characteristics of the tire. Speedo reading tire 1 is assumed accurate tire susp. This allows the wintercontact ts 860 s to remove the thin film of water that develops when friction melts ice or hardpacked snow at the tire contact patch, improving traction and reducing braking distances. Truck tire types and road contact pressures by pedro yap. Tire contact patch pressure distribution model for the static parking. If you could place a car on a glass floor and look at it from below, you would see four patches of rubber, most folks are surprised at the size of these four patches, depending on the vehicle each patch is a little smaller than a hand. From 390 lb to 773lb almost double the tire load the contact patch size only increases by 25%, even assuming laterally constrained sidewalls. The discussion is limited to the comparison of the static and free rolling states of both tire types, examination of the effect of the bead. An ultra fuel efficient, all position tire that also provides high mileage and enhanced casing durability. The size and shape of the contact patch, as well as the pressure distribution within the contact patch, are important to the ride qualities and handling characteristics of a vehicle. Low profile tires most performance tires have a short and wide contact. A wider tire will give a shorter but wider contact patch whereas a narrower tire will give you a longer patch but the. Clean the excess paint off the tire, replace the paper with a clean piece. The prescale film can precisely measure pressure, pressure distribution and pressure balance.
Effect of tire pressure and type on response of flexible. Roll the jeep over the paper to allow the tire to make an impression on the paper. It is the only connection between the road and your rv. As shown in figure 2, tire angle is greater than tireroad contact patch angle for the reason that tire will act as a torsional spring, in which kingpin angle is greater than the actual tire angle. The extreme low pressure film records a range of 0. From tire specs to tire maintenance and everything in between we have the data you need. Furthermore, for the actual tire with carcass compliance, the spin torque will. As your friend stated, though, the tread patterndepth will have a lot to do with how the tire performs during inclement whether.
Tire contact pressure table 1 truck tire performance properties many factors, both tire related and operations related will affect this tireroadway interaction. Use the measured contact stresses as inputs to numerical models of pavement response and performance currently under development. In addition, the shape of the contact patch will influence the performance of the tire and the vehicle its mounted on. Pdf analysis of tire contact parameters using visual processing. Statistically, the larger the load on the tire, the larger its contact patch. Analysis of vehicle static steering torque based on tire. Just a few inches of your tires touch the road at any given time. The lower the load rating and the lower the tire pressure the more deflection and more contact patch, high load rating higher pressure the less deflection and less contact patch. Reducing air pressure or increasing the weight on a tire increases the size of the contact patch. Analysis of tire contact parameters using visual processing.
If the tire pressure is held constant, the width of the tire can only change the shape of the contact patch. The effect of contact patch restriction for tire vibration characteristics. Inch up is the process of mounting a lower aspect ratio tire and larger diameter wheel on your car. The force from the weight on the tire must be equaled by the tire in terms of pressure x area. Internationales stuttgarter symposium pp 12491264 cite as. Low inflation pressures tended to cause the wheel load to be distributed more heavily to the contact patchs central area for the radial tire and more heavily to the sidewall contact area for the bias tire. Effect of tire pressure and type on response of flexible pavement. The tire contact patch, often referred to as the tires footprint, is the small portion of the vehicles tire that comes in contact with the roadway.
In this area the best stopping distances are achieved and the size of the tyre contact patch stays stable. The design of the contact patch is an engineering feat that is specific not only to each manufacturer, but for each individual tire. This part covers the dynamics of a tire s contact patch. The tire contact patch, or tire footprint, is the area of the tire that directly connects the vehicle with the driving surface. It differs for different types of tyres and sometimes under different road conditions. Harzole up303g60 60pc tire repair patch small medium and square patch 30pc 218 5454mm square patch, 15pc 158. These two properties, however, are not perfectly proportional with the contact patch. Measured tireroad contact stresses tire type, wheel load. This means when the vehicle has weight on the tire the tire will deflect and deform to the surface of the ground. I got an a in college physics so why dont i get the bigger contact patch thing with a wider tire. The tire is the only component of a vehicle in direct contact with the road surface and transmit the enginemotor power of driving, turning and stopping to the road.
Tire contact patch characterization through finite element modeling and experimental testing thomas mathews vayalat the objective of this research is to provide an indepth analysis of the contact patch behavior of a specific passenger car tire. This part covers the dynamics of a tires contact patch. Pdf laboratory investigation of the landing aircraft. Estimation of vertical load on a tire from contact patch.
Evaluation of tire tread and body interactions in the contact. This approach uses the tire test bench with the set of contact patch monitoring based on image processing procedures. Truck tire types and road contact pressures by pedro yap the. For high performance driving, the tires contact patch would. The shape of a tires contact patch or footprint greatly influences its performance and is dependent on its profile or aspect ratio. Weight and safety tip, tire contact patch escapees rv club. Utilizing vtred technology, the eagle ultra grip gw3 efficiently evacuates water and slush away from the contact patch for excellent traction and the ultimate. Their study concluded that an increase in tire inflation pres sure from 75 to 125 psi produced an increase in the tensile.
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