Contact patch length and normal load using intelligent tires and its application in. 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. 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. Inch up is the process of mounting a lower aspect ratio tire and larger diameter wheel on your car. 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. Analysis of vehicle static steering torque based on tireroad. 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. The application listed below is a general reference, therefore, tire approval status shall be con. Bridgestone develops tires that result in the maximum performance of vehicles by using ultimat eye, its unique technology to visualize the contact patch. 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. Effect of tire pressure and type on response of flexible. Mundl 2003 evaluation of tire tread and body interactions in the contact patch. Measurement of the tire dynamic transfer stiffness at.
The vertical load on a moving tire was estimated by using accelerometers attached to the inner liner of a tire. 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. This includes the weight resting on the tire contact patch plus any aerodynamic downforce. Tread radius is the curvature of the tread, shoulder to shoulder. Weight and safety tip, tire contact patch escapees rv club. As your friend stated, though, the tread patterndepth will have a lot to do with how the tire performs during inclement whether. The tire contact patch all vehicles are supported by a cushion of air contained in four flexible rubber tires. Town fair tire tire contact patch also known as tire footprint. This means when the vehicle has weight on the tire the tire will deflect and deform to the surface of the ground. From tire specs to tire maintenance and everything in between we have the data you need.
Examine stress distributions across the tire contact patch. Given this alone, the contact patch area should be constant for a given tire pressure and load. In this paper, we focus on the effect of contact patch restriction, which influences. Use the measured contact stresses as inputs to numerical models of pavement response and performance currently under development. I got an a in college physics so why dont i get the bigger contact patch thing with a wider tire.
Since the wear characteristics of tires is a highly competitive area. This is part 6 of my 10 part series on how race car tirestyres work. A laboratory study was conducted to measure vertical tire contact pressures to obtain a. Jul 02, 2016 this is part 6 of my 10 part series on how race car tirestyres work. Estimation of the tire contact patch length and normal load using. 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. Clean the excess paint off the tire, replace the paper with a clean piece. Town fair tire tire contact patch also known as tire. Reducing air pressure or increasing the weight on a tire increases the size of the contact patch.
Getting a grip examining the elements of tire traction. It is most commonly used in the discussion of pneumatic tires, i. Harzole up303g60 60pc tire repair patch small medium and square patch 30pc 218 5454mm square patch, 15pc 158. So for the same tire drop of 6% the 29 wheel has a 2. Measured tireroad contact stresses tire type, wheel load.
Believe it or not, most tires have a fairly small contact patch a little larger than the size of your hand. 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. Pdf laboratory investigation of the landing aircraft. In addition, the shape of the contact patch will influence the performance of the tire and the vehicle its mounted on. Your guide to tire specs, sizing, industry code information and more. Tire contact pressure table 1 truck tire performance properties many factors, both tire related and operations related will affect this tireroadway interaction. In this area the best stopping distances are achieved and the size of the tyre contact patch stays stable. 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. An ultra fuel efficient, all position tire that also provides high mileage and enhanced casing durability.
Tire vibration has complex behavior due to tire contact with the road and rolling. With the tire at 35 psi paint two to three rows of tread. 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. Roll the jeep over the paper to allow the tire to make an impression on the paper. 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. Hudson research report number 11902f research project 388891190 tire contact pressure distributions.
If the tire pressure is held constant, the width of the tire can only change the shape of the contact patch. A wider tire will give a shorter but wider contact patch whereas a narrower tire will give you a longer patch but the. 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. Speedo reading tire 1 is assumed accurate tire susp. Analysis of tire contact parameters using visual processing. Vertical load is the load actually seen at the tire contact patch. This paper discusses the application of noncontact methods to analyze the tire surface contact interaction. The higher the inflation pressure, the smaller the contact patch of tires becomes. Contact patch is the portion of a vehicles tire that is in actual contact with the road surface. Griptester fitted with both tires at a range of tire inflation pressures and for a. From 390 lb to 773lb almost double the tire load the contact patch size only increases by 25%, even assuming laterally constrained sidewalls.
Specially designed sipe channels in the tread wick water vertically into the sipes, where it is then drained into larger grooves. Figure 6 shows the tyre contact size against tyre pressure from 0. Low profile tires most performance tires have a short and wide contact. 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. 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. The paper discusses the first three phases of the project.
To measure the contact patch of the tyre, a prescale film of fujiflim is used. Pacejka, in tire and vehicle dynamics third edition, 2012. Next to the friction coefficient between tire and road, these forces. The difference got me to thinking about how the front tire contacts the ground, though. With respect to tire shape, the area of interest is the crown region and the dimensions of tread width and tread radius, figure 15. The tire contact patch where the rubber meets the road. In order to ensure a purely uniaxial excitation at the conta ct patch of the tire, the motion of the hydraulic shaker table will be monitored and controlled through a time wave form replication twr algorithm 7. 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. Truck tire types and road contact pressures by pedro yap the.
Their study concluded that an increase in tire inflation pres sure from 75 to 125 psi produced an increase in the tensile. Small ground robot to estimate the tireroad friction, tire science and. This part covers the dynamics of a tires contact patch. 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. The prescale film can precisely measure pressure, pressure distribution and pressure balance. Truck tire types and road contact pressures by pedro yap. Just a few inches of your tires touch the road at any given time. Line up the paper on the floor, taping it down will keep it from moving or sticking to the tire. Characterize the contact stresses as a function of wheel type, wheel load, and inflation pressure. Tire contact patch characterization through finite element. Effect of tire pressure and type on response of flexible pavement. If it turns more like an automobile, then there would be a larger contact patch good for braking. The force from the weight on the tire must be equaled by the tire in terms of pressure x area.
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. 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. Infinicoil belt technology optimizes the shape of the contact patch for longer tread life and strengthens the crown against shocks and impacts. The effect of contact patch restriction for tire vibration characteristics.
Pdf analysis of tire contact parameters using visual processing. Furthermore, for the actual tire with carcass compliance, the spin torque will. The maximum width of the contact patch or footprint is determined by the tires tread width. You buy new and larger tires and possibly wheels for your jeep and you wonder whats the proper pressure. Tireseasy december 10, 2012 tire safety, tire technology. A graph showing the resulting profile appears in figure 3 for a tyre of unloaded radius 0. 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. The contact patch is the only connection between the road and the vehicle. Contact patch data was related to insitu measurement of wet grip measured using. 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. Spin, longitudinal and side slip, the width effect. The contact patch is fairly small for a large rv, with each patch being about the size of half of a sheet of paper. It is commonly used in the discussion of pneumatic i. This part covers the dynamics of a tire s contact patch.
Evaluation of tire tread and body interactions in the contact. Tire, finite element modeling, footprint phenomena, contact patch. Analysis of vehicle static steering torque based on tire. The shape of a tire s contact patch or footprint greatly influences its performance and is dependent on its profile or aspect ratio. The tire contact patch, or tire footprint, is the area of the tire that directly connects the vehicle with the driving surface. Utilizing vtred technology, the eagle ultra grip gw3 efficiently evacuates water and slush away from the contact patch for excellent traction and the ultimate. Estimation of vertical load on a tire from contact patch. The vehicle can only put its own weight on the tire. These two properties, however, are not perfectly proportional with the contact patch. 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. The contact patch of a tyre is the section of the tyres tread that is in physical contact with the road surface. Jan 25, 2014 the tire contact patch all vehicles are supported by a cushion of air contained in four flexible rubber tires. Advanced tensile technology helps to improve the strength of the belt package. Inflation and pressure plays a huge role on the contact patch of tires.
For high performance driving, the tires contact patch would. In general terms, a wider tire has a greater contact patch with the ground, so can provide traction. This approach uses the tire test bench with the set of contact patch monitoring based on image processing procedures. Hudson research report number 11902f research project 388891190 tire contact pressure. The movement of tire can be divided into two processes in static steering. If the wheel turns much like a motorcycle wheel, then it seems like the tire would be riding on its edge. Its often different than the stock tires since the larger tires are likely a different weight rating and constructed a bit different. As a result, not much of the tires surface area is touching the ground. 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. In fact, a typical tire contact patch is about the size of your hand. Statistically, the larger the load on the tire, the larger its contact patch.
Longer and narrower tire contact patches are most often found on passenger vehicles. Tire contact patch pressure distribution model for the static parking. Additionally, the calculated contact patch pressure rises from 6. Contact patch for tires archive mbf motorcycle forums.
The extreme low pressure film records a range of 0. Internationales stuttgarter symposium pp 12491264 cite as. The design of the contact patch is an engineering feat that is specific not only to each manufacturer, but for each individual tire. Tire contact patch lowering pressure gain traction. It differs for different types of tyres and sometimes under different road conditions.