For many years durability tests engineers have worked in the
sense of improving the tests that, at first, were performed using
public roads with high time consumption and low reproducibility.
Proving grounds were specially designed to reproduce the most
important efforts to the body and chassis systems, but time problem
was still there.
Time and cost reduction allied to the needs of quality,
reliability and reproducibility improvement led the engineers to
develop methods and equipments to reproduce the durability tests in
the lab. In this way the road simulators appear as a powerful tool
able to perform durability tests with high reliability,
self-controlled and with very low time compared to the road tests.
At this scenery bench tests were also created to components and
systems mainly used to anticipate problems before a whole vehicle
test.
A greater number of bench tests are performed using constant
amplitude sinusoidal signals based on a statistical study of
efforts on a component or system covering the related variables.
However, at the real world, loads come into the vehicle through the
suspension not following any sequence and are present in a random
form varying from tension to compression with infinity of
amplitudes, frequency and cycle average values. Bench tests
improvement pass through to put in consideration the inherent
random phenomenon. Besides, bench tests must be damage equivalent
and be able to reproduce the failure observed at the road.
The main purpose of the work was developing a durability bench
test to the body region where the exhaust vehicle system is
attached. This test should be correlated in damage and failure with
the road, to be used as a reliable alternative to evaluate
durability behavior of this body region. At end, results from road
and bench test were compared.