Development of a Test Bench for Static and Dynamic Tests of a Spring Leaf for the Suspension of Commercial Vehicles 1999-01-2990

Because of the increasing need to reduce the time of development of new products, or even to evaluate the reliability of products, one has been noticing a trend to rationalize field tests through essays in ever more representative test benches, within a shorter period of time at a lower cost.

In the automotive industry, the trend is to increase the reliability of tests in benches. The quantity of simulated parameters is increasing, what demands an ever increasing survey of data based on measurements of signals of deformation of leaves of spring leaf and courses of suspension in experimental vehicles.

In this paper, we intend to show a test bench for static and dynamic tests of spring leaf for the suspension of commercial vehicles, that simulates the critical conditions of operation (earth stretch, ditches and/or obstacles), with a control of course for analyses of strength and deformation, aiming at evaluating the behavior and useful life of the components to improve the comfort level. Comparison among signals measured in field and test bench with curves of: Deflection × Strength, survey of Wöhler S-N curve).

Criteria were established in order to speed up the essay, keeping the extreme conditions for a time longer than that observed in real applications, by reducing the time of low incidence of strengths and courses, this way optimizing the time of test.

The system of suspension in modern vehicles has received a special attention, which has as its basic goal the absorption of vibrations coming from the basis of the winding, the load distribution, better driving and a longer useful life of its components offering a greater comfort and safety to its users. In the past, the concern was only with the load that did not affect the transportation, but sometimes weakened it. The passenger usually got tired with the exhaustive work by using a vehicle under the critical conditions of the roads. The systems of suspension of vehicles transmitted all deformations from the basis of the winding to the passengers, and the components of the vehicles broke more frequently, consuming time with maintenance and transportation delay.

The main advantages of the test in a test bench are: Time of Test, Repetitiveness, Cost and Follow-up through the inspections and graphic records.