The following diagrams show front and rear suspension equivalent stiffness. In this way it is possible to use a lateral stiffness surface spline instead of a constant cornering stiffness. A joint position driver is applied to control rack traslation and, consequently, steer angle.
The steering arm is coupled to the shock absorber body and to the steering rack in the complete model using two spherical joints. As it is possible to see in the following diagrams, suspensions partially meet both the aspects of decreasing camber angle and limited variation of steer angle.
The aim of those analysis is to identify the spring stiffness that makes front and rear suspensions equivalent stiffness very similar. MacPherson strut In the following pitcures it is possible to compare a real MacPherson strut and the model used in simulations.
Rear track with is: Antiroll bars and steering rack are added. Objectives A car suspension system is composed by suspensions and antiroll bars: In the following pictures it is possible to see all details.
Front track with is: The MacPherson suspension, used as front suspension on the car model, includes the lower arm, the shock absorber body and rodthe steering arm and a chassis to fix properly all the components.
Suspensions and antiroll bars attachment points are obtained by manual measurment on a BMW 3 series. In the complete car model is possible to see the antiroll bars, decribed later on the car model section.
Then, one half antiroll bar is coupled to the chassis body using a revolute joint, and to the other half antiroll bar using another revolute joint. A TSDA force is applied between the chassis attachment of the shock absorber body and the upper point of the shock absorber body blue spring in the previous picture.
Introduction The aim of the vehicle suspension system is to ensure the road-wheel contact and to set a good compromise between handling and comfort. The overall car mass is settled on kg.
The chassis mass is settled on kg, applied on the middle point between the two axles in order to achieve an equal weight distribution on the four wheels. The suspension chassis is fixed to the ground and the wheel runs over a bump mm in height.
Simulations and analysis of results — Suspensions characterization The first analysis step is to characterize separately front and rear suspensions.
Results are collected in terms of forces exchanged between wheels and ground as well as cinematic parameters of wheels and car body.
Steering arms are connected to the absorber bodies using a spherical joint. In the following pictures it is possible to appreciate details of front and rear suspensions. The steering rack is coupled to the chassis body by a cylindrical joint and to each steering arm using a spherical joint.
This normally increases the lateral force on the tire. This point center of gravity is about mm high from the ground. Forces between vehicle chassis and the ground can only be exchanged through the wheels, thus it is clear the importance to mantain the contact between them in all the conditions and to have a proper weight distribution.
The Multilink suspension, used as rear suspension on the car model, includes five arms, the hub and the chassis. Each end of the antiroll bar is coupled to a link rod using a spherical joint, the link rod is coupled to the hub rear axle or to the shock absorber body front axle using another spherical joint.
In the complete car model it is Trifilar suspension to see the antiroll bars, decribed later on the car model section. The final result of lateral stiffness surface spline is reported on the following image. All arms are coupled with the hub and the chassis by spherical joints.
Then are exposed the results of the simulations for different road characteristic, varying the stiffness of the suspensions and antiroll bars.
Furthermore, it is possible to observe the wheel characteristic angles in both suspensions, i. It is possible to find in literature the following formula, that we used to calculate the lateral force spline surface: The lower arm is coupled to the chassis using a rotational joint and to the shock absorber body using a spherical joint.The trifilar suspension was assembled and the lengths of the chains were measured, recording their average length.
In order to repeat the experiment, applying the same amount of force each time, a tangential reference line was drawn on the circular platform and marked with a. A B. A trifilar suspension system – 3 chains. Weighing Machine – Weighing the three masses.
HOLLOW CYLINDER & SOLID CYLINDER. RECTANGULAR. Measuring tape – Calculating the lengths of chain. holding a circular Thickness. SidelineSwap is where hockey players buy and sell their gear. Find great deals on new and used hockey equipment & gear, or list for free in seconds.
The Multilink suspension, used as rear suspension on the car model, includes five arms, the hub and the chassis. All arms are coupled with the. Trifilar Suspension Summary The polar moment of inertia for an assembly of solid objects was calculated using the trifilar suspension apparatus.
The periodic time for the experimental and theoretical results were analysed and compared in order to study the relationship between the mass moment of inertia and the mass of an assembly.
Distribuidora de Electricidad DELSUR. El Salvador, Centro América.Download