With a view to simplifying the simulation models and shortening
the computation periods, the author extends the building block
approach (BBA), which is commonly applied to linear analysis with
the finite element method, to non- linear areas, and applies the
extended BBA to drivetrains.
When the frequency of the vibration being studied is more or
less known, the restrictions of the conventional vibration mode
selection method are shown to be significantly relaxed by the modal
compensated method described in this paper. Further, when the BBA
is applied to time-response analysis and the effect of a decrease
in freedom and the time-step-expansion effect of the removal of
high- order components are analyzed, the effect of removal of
high-order components is shown to be particularly great. Also, an
increase in the intensity of nonlinearity necessitates a smaller
time step with the conventional method, whereas the time step with
the BBA is hardly affected by the intensity of nonlinearity. The
effect is that the higher the intensity of nonlinearity, the
greater the BBA-enabled reduction in computation period, With a
light-load drive condition, the computation period is reduced to
one-thirtieth of the original period.
The main cause of noise under a light-load drive condition is
assumed to be impact hitting of the second- and first-stage of
clutch disc. An example of the elimination of impact hitting and
related noise using multi-stage torsional characteristics is given
in this paper. Also, the effect of the clutch discs''
multi-stage torsional characteristics on drivetrain noise under a
heavy-load drive condition is described.