For analysis of A-typelowersuspensionarm we made one model of above mentioned specification, but it is not possible to attach model directly on the testing machine. To hold the model it is necessary to make fixture. We made fixture in the manner that the two bushing point which is connected to the chassis of vehicle must be fixed and one rod inserted in the bush where the load is to apply. Then this inserted rod was supported at two ends as shown in fig 14. And the gradually load is applied up to 5000N.
This paper describe Design, analysis of A-typefrontlowersuspensionarm in commercialvehicle. The main objective of this study was to calculate working life of the component under static loading. The A-typelowersuspensionarm was developed by using CAD software. Actual model was manufacture as per design by using AISI 1040 material. This paper result wasthis model imported in the hyper mesh. After meshing apply load on hub bush they found the weaker section in the model But it is require validating the FEA results with actual experimental test. To validate the FEA results we create a typical A-typesuspensionarm of same material of AISI 1040.as per the consideration in FEA we constraint two bushes and load apply on remaining wheel hub bush on universal testing machine. The load goes on increasing and at last they found the stress in material at maximum stressed area .
ABSTRACT: In New Light commercialvehicle development, Engine is mounted at rear to have low Engine Noise and Vibration inside cabin. At the same time there is a need of high load carrying rear suspension to suit market requirement. In this paper complete design of leaf spring rear suspension for rear engine is discussed.This is non- traditional type of suspension with leaf spring application for rear engine vehicle. Traditionally, for light commercial vehicles, Engine is placed at front/middle giving huge space for traditional rear axle with differential inside. Design of rear suspension is verified and validated successfully for durability and handling by doing finite element analysis and testing.
The design of a suspension system is very important. When the vehicle passes on road, it exhibits the impact loads. We experience the sudden motion along with the vehicle; it is very uncomforted to the passengers. The design of a suspension system comes into the picture under this scenario’s.
The elastoplastic nonlinear case was described using the Ramberg-Osgood uniaxial relation binding stress to deformation. The commercial finite element software Abaqus version 6.4 extrapolates this relationship in the multiaxial case. The sensitivity of certain types of mesh elements makes the execution of the stable implicit integration scheme difficult. Ramberg- Osgood and Mansson-Coffin relation allow us to describe two areas: high-cycle fatigue area and low cycle fatigue area. In the case of damping then in the rigid case even despite the comfort gain when using a damper and a spring, the fatigue life value of certain automotive parts such as a lower
Wishbone lengths are obtained by wheel track width and chassis mounting points. The lines of upper and lower wishbones are extended, they intersect at a certain point which is known as Instantaneous center of rotation. Then line is extended from instantaneous center of rotation to a point at which tire is in contact with the ground. The point at which this line intersects the vehicle center line is called the Roll Centre. Now by extending a line from instantaneous center of rotation to the steering arm this gives exact tie rod length.
Table 1 shows the structure of the suspension system of FSAE of several universities. Literatures [2- 12,15,16]showed most race cars use so-called double wishbone suspension or sometimes called double A-armsuspension. However, various combinations of pushrod and pullrod suspensions have been used in the front and the rear. For example, as mentioned in , formula one cars generally use pushrod in the front and pull rod in rear. As evident from [3, 4, 5] this combination is quite popular in formula student vehicles too. Some student formula vehicles like [6, 7, 8], have used a reverse combination i.e., pullrod in front and pushrod in rear. Many formula student cars as in [9, 10, 11] also use either pushrod or pullrod suspension in both front and rear axles. The advantage of using push orpull rods is that it reduces unsprung weight by moving the spring and damper inboard the vehicle. The main difference between push and pull rods is the forces acting on the push and pull rod (Figure 2). In a pushrod setup, the push rod is under compression as the vertical wheel force pushes on the push rod as the wheel jounces. In a pull rod setup, the vertical wheel force pulls on the pull rod as the wheel jounces. Each of these setups has its benefits and drawbacks. The center of gravity (CoG) is lower in pull rod suspension while it is harder toaccess the spring and damper as it sits so low in the car. Push rod setup, on the other hand, has a higher CoG while making access to the spring and damper much easier as it sits so highin the car. Buckling of the push rod also has to be considered as the load is compressing the push rod there is a risk of it buckling.
The arms were decided to keep as long as possible for the stability of the vehicle and minimize the variations in geometry. The length of the upper arms was decided through geometry modeling, shorter upper arm meant negative camber in bump travel and optimum roll-camber coefficient. The design of suspension begins with considering some important factors. The requirement for a good suspension system is to select good dampers, types of suspension system considering which is best suited for the current chassis design and steering system.
As a result of these limitations, American cars in 1935 generally adopted independent frontsuspension. Poor roads on the European continent encouraged Ford and General Motors to transfer this US technology across the Atlantic to their subsidiaries in Germany and Britain. Some European companies such as Lancia and Morgan had anticipated the Americans moves and quickly all manufacturers adopted independent front wheel suspension even for commercial vans. Over the years many types of independent frontsuspension have been tried. Many of them have been discarded for a variety of reasons, with only two basic concepts, the double wishbone and the McPherson strut, finding widespread success in many varying forms
and handling qualities of an automobile are greatly affected by the suspension system, in which the suspended portion of the vehicle is attached to the wheels by elastic members in order to cushion the impact of road irregularities. Suspensionarm is one of the main components in the suspension systems. It can be seen in various types of the suspensions like wishbone or double wishbone suspensions. Most of the times it is called as A-type control arm. It joins the wheel hub to the vehicle frame allowing for a full range of motion while maintaining proper suspension alignment.
Between the outboard ends of the arms is a knuckle with a spindle (the kingpin), hub, or upright which carries the wheel bearing and wheel. Knuckles with an integral spindle usually do not allow the wheel to be driven. A bolt on hub design is commonly used if the wheel is to be driven. At the knuckle end, single ball joints are typically used, in which case the steering loads have to be taken via a steering arm, and the wishbones look A- or L- shaped. A L-shaped arm is generally preferred on passenger vehicles because it allows a better compromise of handling and comfort to be tuned in. The bushing in line with the wheel can be kept relatively stiff to effectively handle cornering loads while the off-line joint can be softer to allow the wheel to recess under for a impact loads. For a rear suspension, a pair of joints can be used at both ends of the arm, making them more H-shaped in plain view. Alternatively, a fixed-length drive shaft can perform the function of a wishbone as long as the shape of the other wishbone provides control of the upright. This arrangement has been successfully used in the Jaguar IRS. In elevation view, the suspension is a 4-bar link, and it is easy to work out the camber gain see camber angle) and other parameters for a given set of bushing or ball joint locations.
There are thirty nine constraints in the conventional model. The upper and lower A-arms are connected to the uprights by ball (or spherical) joints, and are both mounted to the chassis by hinge (or revolute) joints. A revolute joint added between the front wheel and the upright represents the wheel bearing. In the rear, each trailing arm is connected to the chassis with a revolute joint, and each rear wheel is connected to a trailing arm with a revolute joint. The two wheels are connected to the rear axle by constant velocity joints, (similar in function to a universal joint). With the additional torsional anti-bar mounted in the front of vehicle, the basic mechanical design is unchanged, but there two additional rigid bodies, two additional revolute joints, and two additional massless links to model the bar and its connections. In the interconnected model, four bell-cranks are mounted on the chassis with revolute joints. The linkage connecting the front and rear bell-cranks is modelled as a massless link. The rear bell-crank is connected to the trailing arm with another massless link, and the front bell-crank now carries the front anti-roll bar. Note that each type of joint has differing numbers of constraints, e.g., a spherical joint imposes three constraints, while a revolute joint adds five. In the end, regardless of the interconnection mechanism, all three variations have thirteen degrees of freedom.
The vehiclesuspension system is responsible for driving comfort and safety as the suspension carries the vehicle-body and transmits all forces between body and road. Positively, in order influence these properties, semi-active or active components are introduced, which enable the suspension system to adapt to various driving conditions. From a design point of view, there are two main categories of disturbances on a vehicle namely the road and load disturbances. Road disturbances have the characteristics of large magnitude in low frequency (such as hills) and small magnitude in high frequency (such as road roughness). Load disturbances include the variation of loads induced by accelerating, braking and cornering. Therefore, a good suspensiondesign is concerned with disturbance rejection from these disturbances to the outputs. A conventional suspension needs to be “soft” to insulate against road disturbances and “hard” to insulate against load disturbances. Consequently, the suspensiondesign is an art of compromise between these two goals. The Wishbone lowerarm is a type of independent suspension used in motor vehicles. The general function of control arms is to keep the wheels of a motor vehicle from uncontrollably swerving when the road conditions are not smooth. The control armsuspension normally consists of upper and lower arms. The upper and lower control arms have different structures based on the model and purpose of the vehicle. By many accounts, the lower control arm is the better shock absorber than the upper arm because of its position and load bearing capacities In the automotive industry, the riding comfort and handling qualities of an automobile are greatly affected by the suspension system, in which the suspended portion of the vehicle is attached to the wheels by elastic members in order to cushion the impact of road irregularities.
In application to Finite Element leaf spring models, linear elastic stresses from Finite element analysis can be used directly to calculate total deformation. It can be shown that, design and simulation stresses satisfying maximum stress failure criterion; hence design is safe. In ANSYS Workbench 16.0,Static analyzedusing ACP Tool predicting CAE result in terms of stress and Total deformation .Total reduction in max stress and deformation is respectively 3.09% and12.59%.
A spring is defined as an elastic body, whose function is to distort when loaded and to recover its original shape when the load is removed. Leaf springs absorb the vehicle vibrations, shocks and bump loads (induced due to road irregularities) by means of spring deflections, so that the potential energy is stored in the leaf spring and then relieved slowly. Ability to store and absorb more amount of strain energy ensures the comfortable suspension system. Semi-elliptic leaf springs are almost universally used for suspension in light and heavy commercial vehicles. For cars also, these are widely used in rear suspension. The spring consists of a number of leaves called blades. The blades are varying in length. The blades are us usually given an initial curvature or cambered so that they will tend to straighten under the load. The leaf spring is based upon the theory of a beam of uniform strength. The lengthiest blade has eyes on its ends. This blade is called main or master leaf, the remaining blades are called graduated leaves. All the blades are bound together by means of steel straps.
Abstract: This paper is focused on numerical analysis of a hydraulic arm for use on a light goods vehicle. The designed arm is used for loading and manipulation with load up to 300 kg. Its load capacity depends on the light goods vehicle to be placed on. Great operability of this mechanism predetermines its wide application, e.g. in construction, transport, business etc. Firstly, analytical calculations of the forces, moments and reactions are introduced. Further, locations and values of the maximum stress in the structure of the designed hydraulic arm are calculated using the FEM software. These results determine the relevant data necessary for correct design functioning of the machine. After carrying out all the analyses and calculations we will be able to determine the safe use of the designed handling machine and put it into operation.
Generally, the suspension systems are categorized into two groups, dependent and independent system. A suspension connected to a rigid axle between the left and the right of the wheels is called a dependent suspension since the vertical movement of one wheel is delivered to the opposite wheel in these cases. The major disadvantage of this rigid steer able axle is their susceptibility to tramp-shimmy steering vibrations . The independent suspension system allows the left and right wheel to move without affecting the other’s motion. Nearly all the passenger cars and light trucks use an independent frontsuspension because of the advantages in providing room for the engine and also for the better resistance to steering induced vibrations. There are many forms and designs of independent suspensions. However, double wishbone and MacPherson strut suspensions are perhaps the simplest and most commonly used designs.
Magnetic Shock Absorber Based on Eddy Current Damping Effect, is studied the newly developed analytical model is used to design high-performance dampers for a variety of applications. The effectiveness of highly non- linear, frequency, amplitude and magnetic field dependent magneto-sensitive natural rubber components applied in a vibration isolation system is experimentally investigated by measuring the energy flow into the foundation. The vibration isolation system in this study consist s of a solid aluminum mass supported on four magneto- sensitive rubber components and is excited by an electro-dynamic shaker while applying various excitation signals, amplitudes and positions in the frequency range of 20–200 Hz and using magneto sensitive components at zero-field and at magnetic saturation. The energy flow through the magneto-sensitive rubber isolators is directly measured by inserting a force transducer below each isolator and an accelerometer on the foundation close to each isolator.
Length of the berth shall be minimum 1800 mm. Width of the berth shall be minimum 600 mm for 1x2 layout and 560-750 mm for 1x1 layout. The minimum thickness of berth cushion shall be 75 mm. In case of berth orientation along with the transverse axis of the vehicle, the distance between two opposite berths shall be 400 mm minimum. Height of lower berth including uncompressed cushion from the floor should be 300 ± 50 mm. Minimum clear distance between uncompressed lower berth and lower face of upper berth shall be 800 mm minimum. Clear distance between uncompressed upper berth and inner panel of the roof of the bus shall be minimum 800 mm. In case of Air-conditioned Sleeper coaches it will be minimum 500 mm near the sidewall and 800 mm near side of the gangway. The berth shall be able to withstand a total load of 300 kg, wherein 100 kg load is applied on the area of 400 mm x 400 mm at three places namely one at center and two at extreme ends. After the test, there shall not be any visual deformation of the berth structure as well as breakage of berth anchorages.
Modal analysis or Eigen value analysis is the most important in finding the dynamic stability of the problems. The dynamic stability is better if the system has better natural or higher natural frequency. If natural frequency is much higher than the operational frequencies, the system will be more stable and static design is enough for the problem. The present design is for maximum speed of the truck of 100 kmph with a wheel diameter of 0.71m. So the operational frequency is as calculated below.