Internal combustion engines are designed to meet the high power,
low fuel consumption and also, low exhaust emissions. The engine
running conditions is valid the concept that, the expectative is
very high because of the variety of operating conditions like cold
start, frequent start and stop, time high speed and load,
traditional gasoline, mix of gasoline and alcohol and finally,
alcohol fuel only.
Considering such demand, this paper explains the relationship
between the reliability bathtub curve, specifically the
"Infant Mortality" portion. The bathtub curve describes
failure rate as a function of time. The "Infant
Mortality" portion of the curve is the initial section for
which the failure (death) rate decreases with time (age). In
general, these problems are related to manufacturing aspects or
poor design definitions.
With development of technology, hard failures, the ones that
cause dependability, are becoming rare. On the other hand, soft
failures, the ones that cause poor customer perception, are
increasing with competition and customer high demand. This paper
focuses on a literature review of these two categories, approaching
firstly the mechanisms of failures and secondly, a short
description of the basic concepts. Also, a special emphasis is
given to engine noises.
Throughout this discipline to understand the failure mechanism
and then, the basic concepts, it is expected to: 1) concentrate on
perfect systems, not perfect components, 2) understand interaction
failure modes and finally 3) do not pack more functionality into
one button just because you can, the paper discusses the
relationship with engine typical failure modes. In addition, better
advanced quality plans and control plans can be performed.