characteristics of tyres

just know about the automotive's like suspension, engine, tyres, etc.

1. BHARATH UNIVERSITY DEPARTMENT OF AUTOMOBILE ENGINEERING DONE BY UMA SHANKAR. S (U12AM041) PRADEEP. S (U12AM027) PRABHANJAN.R.P (U12AM026) ARUN KUMAR. M (U12AM005) JAYANTH (U12AM015) VIJAY. P (U12AM043) TYRE AND TYRE WEAR

2. INTRODUCTION HISTORY MATERIALS AND COMPONENTS SPECIFICATIONS TYRE WEAR PERFORMANCE CHARACTERISTICS MARKINGS VEHICLE APPLICATIONS SAFETY AND PRECAUTIONS CONCLUSION REFERENCE CONTENTS

3. A  tyre  (American English) or  tyre  (British English),  is a ring-shaped vehicle component that covers the  wheel's rim  to protect it and enable better vehicle performance. Most tires, such as those for automobiles and bicycles, provide  traction  between the vehicle and the road while providing a flexible cushion that absorbs shock. The spelling  tyre  does not appear until the 1840s when the English began shrink fitting railway car wheels with malleable iron. Nevertheless, traditional publishers continued using  tire .  The Times  newspaper in Britain was still using  tire  as late as 1905. The spelling  tyre , however, began to be commonly used in the 19th century for pneumatic tires in the UK. Another origin of "tire" is provided by Online Etymology Dictionary,  essentially that the word is a short form of "attire," and that a wheel with a tire is a dressed wheel. Some other etymologists may share this view. INTRODUCTION

4. Historically, the spelling was "tire" and is of French origin, which comes from the word tirer , to pull. The reason for this naming is that originally "tire" referred to iron hoops or thick wires bound to carriage wheels. In French blacksmithing the word for a drawn iron rod is a tirer , or pull. The same word was often used for any metal drawing or rolling process. In an article in the London Magazine/Intelligencer of 1853 "The Utility of Broad Wheels," it explains that the common practice was to bend two rods, called "tires," into hoops and bind them to the wheel, but it is preferable to use an iron band, called a "broad wheel" rather than the rods, because as the rods wear they bite into the wheel. Another early mention of a tire in English is in The Scots Magazine, Volume 15 By James Boswell (1753). The  1911 edition of the Encyclopedia Britannica  states that "[t]he spelling ' tyre ' is not now accepted by the best English authorities, and is unrecognized in the US",  while  Fowler's Modern English Usage  of 1926 says that "there is nothing to be said for ' tyre ', which is etymologically wrong, as well as needlessly divergent from our own [sc. British] older & the present American usage". However, over the course of the 20th century  tyre  became established as the standard British spelling. HISTORY

5. In 1892 Dunlop's patent was declared invalid because of prior art by forgotten fellow  Scot   Robert William Thomson  of London (patents London 1845, France 1846, USA 1847), although Dunlop is credited with " realising rubber could withstand the wear and tear of being a tire while retaining its resilience".  J B Dunlop and Harvey du Cros together worked through the ensuing considerable difficulties. They employed inventor Charles Kingston Welch and also acquired other rights and patents which allowed them to protect their business's position. The development of this technology hinged on myriad engineering advances. In terms of materials, the  vulcanization  of natural rubber which he patented in 1844 is credited to  Charles Goodyear  and Robert William Thomson. HISTORY

6. Cords Elastomer Treads Tread lug Tread void Rain groove Sipe Wear bar Bead Sidewall Shoulder Ply MATERIAL S AND COMPONENTS

7. CORDS The cords, which form the  ply  and  bead  and provide the tensile strength necessary to contain the inflation pressure. ELASTOMETER The elastomer , which forms the  tread  and encases the cords to protect them from abrasion and hold them in place. TREADS The tread is the part of the tire that comes in contact with the road surface. The portion that is in contact with the road at a given instant in time is the  contact patch . TREAD LUG Tread lugs provide the contact surface necessary to provide traction. As the tread lug enters the road contact area, or footprint, it is compressed. TREAD VOID Tread voids provide space for the lug to flex and deform as it enters and exits the footprint. Voids also provide channels for rainwater, mud, and snow to be channeled away from the footprint. MATERIALS AND COMPONENTS

8. RAIN GROOVE The rain groove is a design element of the tread pattern specifically arranged to channel water away from the footprint. Rain grooves are circumferential in most  truck  tires. SIPE Tread lugs often feature small narrow voids, or sipes , that improve the flexibility of the lug to deform as it traverses the footprint area. This reduces  shear stress  in the lug and reduces heat build up. WEAR BAR Wear bars (or wear indicators) are raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit. BEAD The bead is the part of the tire that contacts the  rim  on the wheel. The bead is typically reinforced with steel wire and compounded of high strength, low flexibility rubber. The bead seats tightly against the two rims on the wheel to ensure that a tubeless tire holds air without leakage. MATERIAL S AND COMPONENTS

9. SIDE WALL The sidewall is that part of the tire that bridges between the tread and bead. The sidewall is largely rubber but reinforced with fabric or steel cords that provide for tensile strength and flexibility. SHOULDER The shoulder is that part of the tire at the edge of the tread as it makes transition to the sidewall. PLY Plies are layers of relatively inextensible cords embedded in the rubber to hold its shape by preventing the rubber from stretching in response to the internal pressure. MATERIAL S AND COMPONENTS

10. WHEEL Tires are mounted onto  wheels  that most often have integral rims on their outer edges to hold the tire. Automotive wheels are typically made from pressed and welded steel, or a composite of lightweight metal  alloys , such as aluminum or magnesium. The mounted tire and wheel assembly is then bolted to the vehicle's  hub . A decorative  hubcap  and trim ring may be placed over the wheel RIM The beads of the tire are held on the  rim , or the "outer edge" of a wheel. These outer edges are shaped to obtain a proper shape on each side, having a radially cylindrical inclined inner wall on which the tire can be mounted. Tires are mounted on the wheel by forcing its beads into the channel formed by the wheel's inner and outer rims. ASOCIATED COMPONENTS

11. INNER TUBE Most bicycle tires, many motorcycle tires, and many tires for large vehicles such as buses, heavy trucks, and tractors are designed for use with inner tubes. Inner tubes are  torus -shaped balloons made from an impermeable material, such as soft, elastic synthetic rubber, to prevent air leakage. The inner tubes are inserted into the tire and inflated to retain air pressure. VALVESTEM The valve stem is a tube made of metal or rubber, through which the tire is inflated, with a  check valve , typically a  Schrader valve  on automobiles and most bicycle tires, or a Presta valve  on high-performance bicycles. Valve stems usually protrude through the wheel for easy access. ASSOCIATED COMPONENTS

12. TIRE PRESSURE MONITORING SYSTEM Tire pressure monitoring systems (TPMS) are electronic systems that monitor the tire pressures on individual wheels on a vehicle, and alert the driver when the pressure goes below a warning limit. There are several types of designs to monitor tire pressure. INFLATION PRESSURE Tires are specified by the vehicle manufacturer with a recommended inflation pressure, which permits safe operation within the specified load rating and vehicle loading. Most tires are stamped with a maximum pressure rating. The effectiveness of the use of nitrogen vs. air as a means to reduce the rate of pressure loss is baseless, and has been shown to be a bogus marketing gimmick One study noted a 1.3 psi (9.0  kPa ; 0.090 bar) difference (from an initial pressure of 30 psi (210  kPa ; 2.1 bar)) for air-filled vs. nitrogen-filled tires. However, the statistical significance of the purported 1.3 psi (9.0  kPa ; 0.090 bar) difference in the latter study is questionable, since no  t -test nor  p  values were reported. SPECIFICATIONS

13. LOAD RATING Tires are specified by the manufacturer with a maximum load rating. Loads exceeding the rating can result in unsafe conditions that can lead to steering instability and even rupture. For a table of load ratings, see tire code . SPEED RATING The speed rating denotes the maximum speed at which a tire is designed to be operated. For passenger vehicles these ratings range from 160 to 300 km/h (99.4 to 186 mph). For a table of speed ratings, see  tire code . SERVICE RATING Tires (especially in the U.S.) are often given service ratings, mainly used on bus and truck tires. Some ratings are for long haul, and some for stop-start multi-drop type work. Tires designed to run 500 miles (800 km) or more per day carrying heavy loads require special specifications. SPECIFICATIONS

14. WHEEL ALIGNMENT Wheel alignment is the procedure for checking and correcting this condition through adjustment of  camber ,  caster  and  toe  angles. These settings also affect the handling characteristics of the vehicle . RETREAD Tires that are fully worn can be re-manufactured to replace the worn tread. This is known as retreading or recapping, a process of buffing away the worn tread and applying a new tread. Retreading is economical for truck tires because the cost of replacing the tread is less than the price of a new tire. Many commercial trucking companies put retreads only on trailers, using only new tires on their steering and drive wheels. This procedure increases the driver’s chance of maintaining control in case of problems with a retreaded tire. SPECIFICATIONS

15. CAUSE AND CONSEQUENCES Consequences of wheel positions deviations Premature tyre wear and the causes Poor steering characteristics Vibration of the vehicle Premature tyre wear and the causes Abnormal or too fast tyre wear originates when irregularities or defects occur to the wheel, the tyre or the vehicle. Other causes of too fast tyre wear are incorrect use of the vehicle and poor maintenance. TYRE WEAR

16. TYRE WEAR

17. Under inflations will cause wear on the shoulders of tire. Over inflation cause wear at the center of tyre . Excessive camber causes the tyre to run at an angle to the road. One side of thread is then worn more than the other .excessive toe-in or toe-out causes wear on the thread edges and a feathered effect across the thread. TYRE WEAR

18. standard tyre wear drawings , possible causes of uneven or accelerated tyre wear: If the thread wear is even, but the tyre is wearing quickly , this may be caused by driving at too high speed or driving in a warm in a warm climate with tyres made of unsuitable rubber. Tyre efficiency as a result of tyre pressure and load: The consequences for the life can be seen for a tyre that is 20% overloaded. The life of the tyre is then decreased by up to 70% if the tyre has 20% under pressure the life of the tyre decreases by up to 74%. TYRE WEAR

19. influence of speed on the life of a tyre : The influence of speed and the ambient temperature is shown. If , for example, efficiency at a speed of 64 kmph and a temperature of 19 C is 100% this efficiency fall to 55% at as speed of 112 kmph . The life of the tyre accordingly decreases by 45%. one –sided tyre ward: Single –sided tread wear is usually caused by an incorrect camber. The wheel is then out of square on the road surface. With the deformation of the tyre the wheel turns on different circumferences. One side wilt slip and result in shoulder wear without ridge formation. TYRE WEAR

20. serrated wear : Serrated wear in the longitudinal direction of the tyre is common on non-driven axles. Because the separate features of the tyre tread forming tread design are not driven but do deform, they wear more quickly on the one side than the other. Vertical and lateral run-out in tyre combinations: It is possible for the wheel to still vibrate after balancing.the cause can be vertical run-out or lateral run-out. Vertical run-out is the up and down movement of the axle pf the turning wheel due to out-of-roundness. Lateral run-out is a consequence of the askew position of the tyre on the tyre on the rim due to dirt between heel and rim edge or the poor fitting the heel. Lateral run-out can also occur after a wheel is fitted on a car. The cause is then askew assembly on the axle due to damage or dirt. TYRE WEAR

21. Balance When a wheel and tire rotate, they exert a  centrifugal force  on the axle that depends on the location of their  center of mass  and the orientation of their  moment of inertia . This is referred to as balance, imbalance, or unbalance. Tires are checked at the point of manufacture for excessive static imbalance and dynamic imbalance using automatic tire balance machines. Circle of forces The circle of forces, traction circle, friction circle, or friction ellipse is a useful way to think about the dynamic interaction between a vehicle's tire and the road surface. PERFORMANCE CHARACTERISTICS

22. PERFORMANCE CHARACTERISTICS

23. STOPPING DISTANCE: Performance-oriented tires have a tread pattern and rubber compounds designed to grip the road surface, and so usually have a slightly shorter stopping distance. However, specific braking tests are necessary for data beyond generalizations. PERFORMANCE CHARACTERISTICS

24. INTERNAL FACTOR EXTERNAL FACTOR Aspect Ratio Road texture and roughness Rim width Aerodynamic drag Tyre size Effect of speed Tyre pattern Effect of load Tread depth Effect of temperature Cord angle Effect of inner tube PERFORMANCE CHARACTERISTICS EFFECT OF COMPONENT ON TYRE PERFORMANCE

25. DOT Code: In the United States, the  DOT Code  is an  alphanumeric  character sequence molded into the sidewall of the tire for purposes of tire identification. The DOT Code is mandated by the  U.S. Department of Transportation . The DOT Code is useful in identifying tires in a  product recall . E-mark: All tires sold for road use in Europe after July 1997 must carry an E-mark. The mark itself is either an upper case "E" or lower case "e" – followed by a number in a circle or rectangle, followed by a further number. An (upper case) "E" indicates that the tire is certified to comply with the dimensional, performance and marking requirements of ECE regulation 30. MARKINGS

26. MODEL SERIAL NUMBER: Tire manufacturers usually embed a mold serial number into the sidewall area of the mold, so that the tire, once molded, can be traced back to the mold of original manufacturer. MARKINGS

27. SIZE CODES: Automobile tires are described by an alphanumeric code, which is generally molded into the sidewall of the tire. This code specifies the dimensions of the tire, and some of its key limitations, such as load-bearing ability, and maximum speed. Sometimes the inner sidewall contains information not included on the outer sidewall, and vice versa MARKINGS

28. MARKINGS

29. Passenger vehicles and light truck High performance High performance tires are designed for use at higher speeds, and more often, a more "sporty" driving style. They feature a softer rubber compound for improved traction, especially on high speed cornering. The trade off of this softer rubber is shorter tread life. High performance street tires sometimes sacrifice wet weather handling by having shallower water channels to provide more actual rubber tread surface area for dry weather performance. VEHICLE APPLICATIONS

30. TYPES OF PATTERNS

31. MUD AND SNOW Mud and Snow, (or M+S, or M&S), is a designation applied rather arbitrarily by manufacturers for all-season and winter tires designed to provide improved performance under low temperature conditions, compared to summer tires. Tires may have well above average numbers of sipes in the tread pattern to grip the ice. There are no traction performance requirements which such a tire has to meet; M&S relates to the percentage of tread void area. Mud tires are specialty tires with large, chunky tread patterns designed to bite into muddy surfaces. The large, open design also allows mud to clear quickly from between the lugs. Mud terrain tires also tend to be wider than other tires, to spread the weight of the vehicle over a greater area to prevent the vehicle from sinking too deeply into the mud. VEHICLE APPLICATIONS

32. ALL SEASON: The all-season tire is a compromise, and is neither an excellent summer tire nor an excellent winter tire. All-Season tires are also marked for mud and snow the same as winter tires but rarely with a snowflake. Owing to the compromise with performance during summer, winter performance is usually poorer than a winter tire. ALL TERRAIN: All-terrain tires are typically used on  SUVs  and  light trucks . These tires often have stiffer sidewalls for greater resistance against puncture when traveling off-road, the tread pattern offers wider spacing than all-season tires to remove mud from the tread. Many tires in the all-terrain category are designed primarily for on-road use, particularly all-terrain tires that are originally sold with the vehicle. VEHICLE APPLICATIONS

33. Light trailer Domestic Trailers  (including camping trailers) for use on public highways often have different tires than those seen on cars. Often they are  bias ply  rather than  radial tires , and they often don't have as aggressive a tread pattern as standard road tires. Off-the-road Off-the-road (OTR) tires include tires for construction vehicles such as wheel loaders, backhoes, graders, trenchers, and the like; as well as large mining trucks. OTR tires can be of either bias or radial construction although the industry is trending toward increasing use of radial. Bias OTR tires are built with a large number of reinforcing plies to withstand severe service conditions and high loads. VEHICLE APPLICATIONS

34. Racing Racing tires are highly specialized according to vehicle and  race track  conditions. This classification includes tires for drag racing, Auto-x, drifting, Time Attack, Road Racing  – as well as the large-market race tires for  Formula One ,  IndyCar ,  NASCAR ,  V8 Supercars ,  WRC ,  MotoGP  and the like. Racing tires often are engineered to minimum weight targets, so tires for a 500-mile (800 km) race may run only 100 miles (160 km) before a tire change. Racing tires often are not legal for normal highway use. Industrial The Industrial tire classification is a bit of a catch-all category and includes pneumatic and non-pneumatic tires for specialty industrial and construction equipment such as  skid loaders  and  fork lift  trucks. VEHICLE APPLICATIONS

35. BICYCLE This classification includes all forms of  bicycle  tires, including road racing tires,  mountain bike  tires, snow tires, and  tubular tires , used also with other human-powered vehicles (see Category: Human-powered vehicles ). AIRCRAFT Aircraft tires are designed to withstand extremely heavy loads for short durations. Aircraft tires generally operate at high pressures, up to 200  pounds per square inch  (14  bar ; 1,400  kPa ) for airliners, and even higher for business jets. Tests of airline aircraft tires have shown that they are able to sustain pressures of maximum 800 pounds per square inch (55 bar; 5,500  kPa ) before bursting. VEHICLE APPLICATIONS

36. Proper vehicle safety requires specific attention to inflation pressure , tread depth, and general condition of the tires. Over-inflated tires run the risk of explosive decompression (they may pop). On the other hand, under-inflated tires have a higher rolling resistance and suffer from overheating and rapid tread wear particularly on the edges of the tread . Tires worn down past their safety margins and into the casing run the very real risk of rupturing. Also, certain combinations of cross ply and radial tires on different wheels of the same vehicle can lead to vehicle instability, and may also be illegal. Vehicle and tire manufacturers provide owner’s manuals with instructions on how to check and maintain tires . SAFETY AND PRECAUTIONS

37. SIZE 14.00R 20 12.00R 20 PRESSURE 20 18 18 16 PATTERN CODE HP 10/ HP 11 HP 10/ HP 11 HP 10 HP 10 RIM 10.0.20 10.0.20 8.5.20 8.5.20 DIMENSION OUT DIAMETER 1232 1232 1122 1122 SECTION WIDTH 375 375 315 315 DIAMETER UNDER DYNAMIC LOAD 579 579 526 526 BASIC DATA LOAD INDEX 164 161 154 152 Kg LOAD 5000 4625 3750 3250 Kpa AIR PRESSURE 790 690 830 770 SPEED G (90 Km/h) K (110 Km/h) SAFETY PERFORMANCE MORE THAN 100 KM AFTER AIR - DEFLATION MAIN TECHNICAL DATA

38. FLAT A flat tire occurs when a tire deflates. This can occur as a result of normal wear-and-tear, a leak, or more serious damage.A flat tire or low-pressure tire should be considered an emergency situation, requiring immediate attention. Some tires, known as " run-flat tires ", have either extremely stiff sidewalls or a resilient filler to allow driving a limited distance while flat, usually at reduced speed, without permanent damage or hazard. SAFETY AND PRECAUTIONS

39. BUBBLE Tire bubbles, also referred to as bulges / bumps / protrusions / carbuncles, occur when the sidewall of the tire has failed, resulting in a protrusion. Causes of bubbles include having an impact at high speed, over inflation, or poor tire construction/manufacturing. It is generally recommended to replace the tire since the probability of tire failure has increased. They can occur on the inner or outer sidewall. SAFETY AND PRECAUTIONS

40. HYDROPLANNING Hydroplaning, also known as aquaplaning, is the condition where a layer of water builds up between the tire and road surface. Hydroplaning occurs when the tread pattern cannot channel away enough water at an adequate rate to ensure a semi-dry footprint area. When hydroplaning occurs, the tire effectively "floats" above the road surface on a cushion of water – and loses traction, braking and steering, creating a very unsafe driving condition. DANGER OF AGED TIRES Research and tests show that as tires age, they begin to dry out and become potentially dangerous, even if unused. Aged tires may appear to have similar properties to newly manufactured tires, but rubber degrades over time, and once the vehicle is traveling at high speeds (i.e. on a  freeway ) the tread could peel off, leading to severe loss of control. SAFETY AND PRECAUTIONS

41. Also, tires on seldom-used trailers are at the greatest risk of age-failure, but some tires are built to withstand idleness, usually with nylon reinforcement. Many automakers recommend replacing tires after six years, and several tire manufacturers ( Bridgestone ,  Michelin ) have called for tires to be removed from service 10 years after the date of manufacture. SAFETY AND PRECAUTIONS

42. Scrap tires and environmental issues Once tires are discarded, they are considered  scrap tires . Scrap tires are often re-used for things from bumper car barriers to weights to hold down tarps. Some facilities are permitted to recycle scrap tires through chipping, and processing into new products, or selling the material to licensed power plants for fuel. The use of scrap tire chips for landscaping has become controversial, due to the leaching of metals and other contaminants from the tire pieces. Zinc is concentrated (up to 2% by weight) to levels high enough to be highly toxic to aquatic life and plants. Of particular concern is evidence that some of the compounds that leach from tires into water, contain hormone disruptors and cause liver lesions. SAFETY AND PRECAUTIONS

43. Flexible sidewalls, Reduced fuel consumption due to less rolling resistance. A softer ride because of the layout of the tire's plies and because of the flex of the sidewalls, assuring more stable contact with the road service and a softer ride. Less vibration, Extended tire life due to less heat generated by the tire. Poor transport handling, since low lateral stiffness causes the tire sway to increase as the speed of the vehicle increases. Increased vulnerability to abuse when overloaded or under-inflated. The sidewall tends to bulge which could cause damage and puncture. A ply layout that causes the radial tire to follow a wheel track more consistently than a bias ply tire. The radial tire is more expensive than a bias ply tire which may be considered as a disadvantage. CONCLUSION

44. Jump up^  See  spelling differences Jump up^   http://www.etymonline.com Jump up^  Peters, Pam (2004).  The Cambridge Guide to English Usage . Cambridge University Press. p. 553.  ISBN   978-0-521-62181-6 . Jump up^  Chisholm, Hugh, ed. (1911).  Encyclopædia Britannica, vol. 26 . Encyclopædia Britannica. p. 1007. Jump up^  Fowler, H. W.; David Crystal (ed.) (2009).  A Dictionary of Modern English Usage: The Classic First Edition . Oxford University Press. p. 655.  ISBN   978-0-19-953534-7 . Retrieved 2010-10-23. Jump up^   Bertman , Stephen (2005).  p.35  Handbook to Life in Ancient Mesopotamia . Oxford University Press. Retrieved 2 August 2014. Jump up^  Sir Arthur Du Cros , Bt,  Wheels of Fortune, a salute to pioneers , Chapman & Hall, London 1938 Jump up^  Dunlop, John Boyd (2008).  Hutchinson Dictionary of Scientific Biography . AccessScience . Retrieved 9 July 2009. ^  Jump up to: a   b  Werner Obrecht , Jean-Pierre Lambert, Michael Happ , Christiane Oppenheimer- Stix , John Dunn and Ralf Krüger "Rubber, 4. Emulsion Rubbers" in Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim .  doi : 10.1002/14356007.o23_o01 Jump up^  Samuel K. Clark, V. E. Gough (1981).  Mechanics of Pneumatic Tires . U.S. Department of Transportation. p. 245. Consider two mechanisms of force transmission acting in parallel. ^  Jump up to: a   b  Samuel K. Clark, V. E. Gough (1981).  Mechanics of Pneumatic Tires . U.S. Department of Transportation. p. 246. The only possible way in which the reaction can develop at the rim is by the changes in magnitude and direction of the membrane stresses at their points of attachment to the rim, in the region of the membrane near the point where the plate is pressed against it. Jump up^  Samuel K. Clark, V. E. Gough (1981).  Mechanics of Pneumatic Tires . U.S. Department of Transportation. p. 246. This force pulls the bead coil against the base of the wheel rim above the contact area, thus transmitting the upward force to the wheel. REFERENCES

45. THANKING YOU