Abstract
KEYWORDS
virtual prototype, suspension, steering, dynamic analysis, simulation.
ABSTRACT
The revolutionary evolutions in the field of motor vehicles imposed the development and utilization of high technologies both for manufacturing and design. The simulation techniques allow the engineers to conceive and equip virtual prototypes, which permit a large-scale evaluation of the system behaviour. In this paper, we attempt to carry out the dynamic analysis of a motor vehicle, using the virtual prototype developed with the MBS software ADAMS of MSC, which is licensed to “Transilvania” University of Brasov in the frame of the “Centre for Integrated Product Design”. The dynamic model takes into consideration the geometric restrictions as well as the nonlinear characteristics of the elastic and damping elements. The virtual prototype includes the front and the rear suspension subsystems, the steering subsystem, and the car body subsystem. Two double-wishbone mechanisms are used for the suspension of the front wheels. The steering subsystem contains a central pitman arm that rotates to impart motion to the left and right tierods. The rear rigid axle is guided by a five-link mechanism, which is a dependent suspension model. The experiment designed is one frequently carried by the automotive manufacturers, namely passing over bumps, the road profile including four bumps of 50 mm amplitude. The connection between wheels - tires and road (ground) is made using contact forces. These allow modelling how adjacent bodies interact with one another when they collide during the simulation. On the virtual prototype, a lot of measurements have been made having in view to evaluate the dynamic behaviour of the vehicle. One of the most important advantages of this kind of simulation consists in the possibility of make easy virtual measurements in any point and/or area of the system and for any parameter. This is not always possible in the real cases due to the lack of space for transducers placement, lack of appropriate transducers or high temperature. This helps to take quick decisions on any design changes without going through expensive hardware (physical) prototype building and testing.