| Summary: | 碩士 === 國立台灣工業技術學院 === 機械工程技術研究所 === 84 === The object of this paper is to develop a simulation model
to analyze thedeformation behavious of material under Shape
Rolling. The Combined NumericalAnalysis Method is used in this
study, which combined the merits of the FiniteElement Method(
FEM) and the Slab Method. In dealing with the large
deformationproblems, it has the merits of high accuracy and
efficiency. Besides,under theassumption of the roll is a rigid
body,this model can effectively analyzed thethree dimensional
steady-state deformation of the materials under rolling.
The material is divided into several elements which are in
the from of 8-node hexahedral isoparametric elements. In shape
rolling process, the materialis assumed to be a rigid-plastic
body with uniform thickness. The distributionof velocity and the
equivalent strain-rate can be calculaed from the velocityat
nodal points and the functional can be minimized by the
variation of thevelocity at all nodal points.The streamlines and
the distribution of thicknesscan be obtained from the velocity
field and boundary condition. More over, thedistribution of the
eqivalent strain of the initial streamlines can be foundby
integrating the eqivalent strain rate along the streamlines
with the SlabMethod.Then,the flow stress can be sloved.On the
assumption of the streamlinesto be the boundaries of the
element, the mesh of new element can be generated.The rigid-
plastic finite element method is applied to slove the mesh of
newelement and the distribution of flow stress curve, and the
distribution ofvelocity,stress,strain and strain rate of the
element can be calculated.Repeatthe above procedures until the
calculated result converges to the assumedcondition, the
analytical results of the steady-state deformation can
beobtained.
In order to verify the availability of the developed
numerical simulationmodel, some experiments of shape rolling are
executed,and it show good coinci-dence with the analytical
results.
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