International Journal of Scientific & Engineering Research, Volume 7, Issue 3, March-2016 164 ISSN 2229-5518 DESIGN AND ANALYSIS OF SUSPENSION SYSTEM FOR AN ALL TERRAIN VEHICLE Shijil P, Albin Vargheese, Aswin Devasia, Christin Joseph, Josin Jacob Abstract—In this paper our work was to study a. Study the static and dynamic parameters of the the static and dynamic parameter of the suspension system chassis. of an ATV by determining and analyzing the dynamics of b. Workout the parameters by analysis, design, and the vehicle when driving on an off road racetrack. Though, optimization of suspension system. there are many parameters which affect the performance of c. Study of existing suspension systems and the ATV, the scope of this paper work is limited to parameters affecting its performance. optimization, determination, design and analysis of d. Determination of design parameters for suspension systems and to integrate them into whole vehicle suspension system. systems for best results. The goals were to identify and optimize the parameters affecting the dynamic performance suspension systems Index terms—All terrain vehicle, suspension, caster angle, within limitations of time, equipment and data from camber angle, toe angle, roll centre manufacturer. In this paper we will also come across the following aspects IJSER negotiate a wider variety of terrain than most other vehicles. Although it is a street-legal vehicle in some countries, it is not legal within most states and provinces of Australia, the United States and 1.INTRODUCTION Canada and definitely not in India. By the current An All-Terrain Vehicle (ATV) is defined ANSI definition, it is intended for use by a single by the American National Standards Institute operator, although a change to include 2-seaters is (ANSI) as a vehicle that travels on low pressure under consideration. tires, with a seat that is straddled by the operator, The All Terrain Vehicle (ATV) was along with handlebars for steering control. In some initially developed in the 1960‟s as a farmtown vehicles steering wheel similar to passenger cars is vehicle in isolated, mountainous areas. During also used. As the name suggests, it is designed to spring thaws and rainy seasons, steep IJSER © 2016 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 7, Issue 3, March-2016 165 ISSN 2229-5518 mountainous roads were often impassable with disciplines as motocross, woods racing, desert conventional vehicles. It soon became a racing, hill climbing, ice racing, speedway, tourist recreational vehicle however, providing trophy, flat track, drag racing and others. transportation to areas inaccessible by other motorized transport. Royal Enfield CO built and 1.2. Application of ATV’s put on sale a powered Quadra cycle in 1893 that Initially the ATVs were solely used for the worked in the same way as, and resembles, a transportation through the inaccessible areas, but modern quad-bike. ATVs were made in the United now these vehicles have found their application in States a decade before 3- and 4-wheeled vehicles different areas as mentioned below: were introduced by Honda and other Japanese a. In Defense Services like army and air force companies. During the 1960s, numerous etc to carry and transport guns, ammunition and manufacturers offered similar small off-road other supplies to remote areas of rough and varied vehicles that were designed to float and were terrain. capable of traversing swamps, ponds and streams, b. By railways during construction of as well as dry land. railway tracks on mountain or on other rough The early ATV‟s were mainly used for terrain. agricultural purpose only. But now the definition c. By police force. of ATV is changing. Many countries are allowing d. In sport also like golf for traveling one place to ATVs as commercial vehicle, though with the other place. regulations on its useIJSER and safety. Now days, ATVs e. In Antarctic bases for research things where use are generally used in defense and sports of conventional vehicle is impossible. application redefining the ATV. Now the ATVs are f. Now a days ATVs are also used in adventuring also coming with durable roll cages, added safety like mountaineering, in dirt and in snow. of seat and shoulder belts and higher ground clearance making it more rugged vehicle. The rear 1.3. Objective cargo deck is more useful for hauling camping The objective of our paper work was to gear, bales of hay, tools and supplies making it study the static and dynamic parameter of the suitable for exploring back country, riding sand suspension system of an ATV by determining and dunes, hunting, fishing and camping. ATVs Sport analyzing the dynamics of the vehicle when models are built with performance, rather than driving on an off road racetrack. Though, there are utility, in mind. To be successful at fast trail riding, many parameters which affect the performance of an ATV must have light weight, high power, good the ATV, the scope of this paper work is limited to suspension and a low center of gravity. These optimization, determination, design and analysis machines can be modified for such racing IJSER © 2016 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 7, Issue 3, March-2016 166 ISSN 2229-5518 of suspension systems and to integrate them into front and rear suspension of a vehicle may be whole vehicle systems for best results. different. The goals were to identify and optimize the parameters affecting the dynamic performance 2.1. Basic Consideration for Suspension suspension systems within limitations of time, System equipment and data from manufacturer. The objective of the paper includes: 2.1.1. Vertical loading e. Study the static and dynamic parameters When the road wheel comes across the of the chassis. bump or a pit on the road it is subjected to vertical f. Workout the parameters by analysis, forces (tensile or compressive) depending on the design,and optimization of suspension system. load irregularity which are absorbed by the elastic g. Study of existing suspension systems and compression, shear, bending, twisting properties of parameters affecting its performance. spring. To reduce the pitching tendency of the h. Determination of design parameters for vehicle, the front system should be less springing suspension system. than the rear suspension system. 2. SUSPENSION SYSTEM 2.1.2. Rolling The suspension of vehicles needs to satisfy The center of gravity (C.G.) of the a number of requirements which depend on vehicle is considerably above the ground. As a different operating conditions of the vehicle result while taking turns the centrifugal force acts (loaded/unloaded, IJSERacceleration/braking, outwards on the C.G. of vehicle, while the load level/uneven road, straight running/ cornering). resistance acts inwards at the wheels. This give rise Suspension systems serve a dual purpose to a couple turning the vehicle about the contributing to the vehicle's handling and braking longitudinal axis called rolling. for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations. The suspension also protects the vehicle itself and mounted systems from damage 2.1.3. Brake dip and squat On applying brakes the nose of the vehicle and wear. dips which depends on the position of C.G. Suspension is the term given to the system relative to the ground, wheel base and other comprise of springs, shock absorbers and linkages suspension characteristics. This phenomenon is that connects a vehicle to its wheels. The design of called as dip. In the same way the torque loads IJSER © 2016 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 7, Issue 3, March-2016 167 ISSN 2229-5518 during acceleration tend to lift the front of vehicle. of leaf springs to it. In dependent suspension This effect is called as squat. system when the camber of one wheel changes, the camber of the opposite wheel changes in the same 2.1.4. Side thrust way (by convention, on one side this is a positive Centrifugal force during cornering, change in camber and on the other side this a crosswinds, cambering of the road causes side negative change). Depending on the location of thrust. system of linkages, the dependent suspension systems have various configurations as: 2.1.5. Road holding The degree to which vehicle maintains the a. Satchell link contact with the road surface in various types of b. Panhard rod directional changes as well as in straight line c. Watt's linkage motion is called as road holding. d. WOBLink e. Mumford linkage f. Live axle 2.1.6. Unsprung weight g. Twist beam Unsprung weight is the weight of the h. Beam axle vehicle components between suspension and road surface (Rear axle assembly, steering knuckle, front Dependent suspension system assures axle, wheels). IJSERconstant camber, it is most commonly used in vehicles that need to carry large loads. 2.2. Types of Suspension System Used in Automobiles Suspension systems can be broadly classified into two subgroups – Dependent and Independent. 2.2.1. Dependent suspension system A dependent suspension normally has a Fig 2. 1: Dependent suspension system using leaf spring beam or live axle that holds wheels parallel to each other and perpendicular to the axle with the help 2.2.2.Indipendent suspension system IJSER © 2016 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 7, Issue 3, March-2016 168 ISSN 2229-5518 In an independent suspension system wheels are allowed to rise and fall on their own without affecting the opposite wheel by using 2.3. Requirements of Suspension Systems kinematic linkages and coil springs. Suspensions a. Independent movement of each of the with other devices, such as anti-roll bars that link wheels on an axle the wheels are also classified in independent b.