| Summary: | 博士 === 國立清華大學 === 動力機械工程學系 === 90 === This work presents a rigorous three-dimensional finite element frictional contact analysis procedure to analyze belt transmission systems, including the flat-belt, V-belt and continuously variable transmission (CVT) systems.
The frictional contact behavior on the contact surface,
which accounts for the power loss of the transmission systems
and the wear of the belt, is investigated in detail.
Based on the transformation matrix established for
satisfying the contact conditions on the contact surfaces
between the belt and pulleys,
an incremental restricted variational principle
with the centrifugal force term
is introduced to model the angular speed effect
of the transmission system operating at a constant angular speed.
Then, the simultaneous algebraic equations for the finite element
frictional contact analysis of the belt transmission system are formulated.
To model the flexible property of the belt,
the three-dimensional bar element and eight-node brick element
are employed to simulate the tension member and rubber layer
of the belt.
For evaluating the contact traction,
to improve the inaccuracy
at the end zones of the contact area due to bending effect,
the incremental Wilson displacement modes
are added to the displacement approximation
of the eight-node brick element.
In addition, appropriate frictional contact and loading conditions are provided
to simulate the physical contact phenomena between the belt and pulley.
For an operating flat-belt transmission system,
the angular speed loss between the driver and driven pulleys
induced by the deformation of the belt and the frictional contact
on the contact surfaces is analyzed.
The effects of dynamic friction coefficient,
traction coefficient and material properties
of the flat-belt on the angular speed loss are also studied.
The effects of angular speed and dynamic friction coefficient
on the contact behavior of the flat-belt transmission system
are presented as well.
On the frictional contact analysis of the V-belt transmission system,
the influences of dynamic friction coefficient
on the normal and tangential contact forces,
the deformation of the V-belt and the distribution of contact tractions
occurred on the contact surfaces
between the V-belt and pulley are thoroughly studied.
Thus, the most possible position of wear
at the edge of the V-belt cross-section
can be observed.
For the CVT system,
the effect of angular speed on the frictional contact behavior
between the V-belt and pulley flange is investigated.
The friction angles of contact points
along the edge of the V-belt cross section
are also evaluated for various dynamic friction coefficients.
The present work should be helpful for the estimation of wear properties
and operation efficiency for belt transmission systems.
Besides, the proposed three-dimensional
frictional contact finite element procedure
can be further applied to deal with the mismatched effect
between the V-belt and pulley flanges
which is caused by the distortion of V-belt cross section
as the belt bends surrounding the pulley.
The belt transmission systems with other types of belt,
such as metal V-belt or toothed-belt, etc,
are also worthwhile to be investigated in the future.
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