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Optimization Design of Cold Roll-beating Experiment
Device Based on ANSYS Workbench
Fanzhi Wei, Mingshun Yang, Qilong Yuan
Faculty of mechanical and precision instrument engineering, Xi’an University of
Technology, Xi’an, China
[email protected], [email protected], [email protected]
Abstract. Cold roll-beating forming technology is an advanced plastic forming
technology. In order to promote the further movement way of this technology
research, a cold roll-beating experiment device is designed in this paper.
Through the cold roll-beating process the beam plays the main role in bearing
and positioning. A parametric model of the frame is built in ANSYS
Workbench. Static and modal analysis is made according to the limiting
working conditions to make sure the beam’s stiffness whether meet the
requirement or not in cold roll-beating process based on the result of analysis.
The frame is optimized by Goal-Driven Optimization (GDO) function of
ANSYS Workbench with topology optimization and shape optimization. After
optimization improved, the frame’s quality is reduced 20.4% to the original
structure and its stiffness is also meet the requirement in cold roll-beating
process.
Keywords: Cold roll-beating, Experiment Device, Optimization Design,
Workbench
1 Introduction
With the development of modern plasticity forming technology, reducing plasticity
forming equipment energy consumption and the forming force, and improving the
producing flexibility and product accuracy has become the main innovation direction
of plasticity forming technology [1-4]. As a plastic forming technology at ordinary
temperatures, Cold roll-beating forming technology features in simple technology
simplicity, low energy -consumption and high efficiency [5]. Cold roll-beating
forming technology uses advantage of the characteristics of the metal plastic forming,
with high speed rolling wheel beating striking the workpiece to force metal flowing,
thus forming a plastic forming technology of partial load, no die, and no constraint
free of parts contour [6]. In this paper, the ANSYS Workbench software is used to
optimize the beam of the device. On the premise of meeting the mechanical properties
of the device, minimizing the quality of the beam can reduce equipment tonnage and
enhance the utilization ratio of materials.
Advanced Science and Technology Letters Vol.121 (AST 2016), pp.125-130
http://dx.doi.org/10.14257/astl.2016.121.23
ISSN: 2287-1233 ASTL Copyright © 2016 SERSC
2. The Design of Cold Roll-beating Device
Mechanical structural design of equipment should guarantee the security, stability,
reliability, simplicity and feasibility. Figure 1 is a specific structure of the device. The
overall size (length, width and height) of the cold roll-beating equipment is
1600×1395×1395 mm, which consists of beam, left and right columns, spindle box
and spindle, workbench and base. Base is fixed on the ground, beam and the left
column through the screw guiding, with the right column by dowel locating, motor
and main spindle by the belt transmission. Before roll- beating process, adjusting
screw and dowel to ensure beam at right height. And then rolling process, the
worktable driven fixture and workpiece to the Y axis is the direction of feed at a
certain speed, motor drives the spindle rotating to finish roll-beating.
Motor
Left column
Workbench
Beam
Spindle box
Right column
Base
Fig. 1. 3D models of cold roll-beating device
3 Modal and Static Analysis of the Device Beam
The part of equipment beam is connected by welding, according to the Saint Venant’s
Principle, chamfering, rounded corners, holes, etc. are ignored. Finite element model
of beam as shown in figure 2. Material of the beam is QT600-3, E = 1.69×105 Mpa,
poisson's ratio μ = 0.286, density ρ = 7.12×10-9
T/mm3. Model the appearance of the
overall size is 906×560×420 mm. Total mass is 240 kg. Adopt the method of the
smart mesh divided into ANSYS Workbench, divided the total number of nodes are
9620, the total number of units are 4592. Model in ANSYS Workbench module
modal analysis is carried out on the beam, get beam first to the fourth order natural
frequency as shown in Figure 3(a)~(d).
Advanced Science and Technology Letters Vol.121 (AST 2016)
126 Copyright © 2016 SERSC
Left plate
Hole 1
Hole 3
Steel plate
Hole 2
Hole 4
Fig. 2. Model for the beam
(a) 1st 766.11Hz (b) 2nd 941.22Hz
(c) 3rd 1513.8Hz (d) 4th 1532.5Hz
Fig. 3. Beam modal shape
The highest speed in motor engineering v=5000 r/min, the biggest vibration
frequency f=83.3Hz. And the beam first-order natural frequency f=766.11 Hz, greater
than the vibration frequency, so in the process of roll-beating, the beam does not
produce resonance. Statics analysis was carried out on the beam, the plate on the left
side and right side hole full constraints, In the process of roll-beating working
extreme conditions, the load to the beam with mandrel surface convex platform the
average pressure is 0.021 Mpa, as shown in the Figure 4.
Advanced Science and Technology Letters Vol.121 (AST 2016)
Copyright © 2016 SERSC 127
(a) Displacement nephogram (b) Equivalent stress nephogram
Fig. 4. Static deformation picture
Maximum deformation is 0.0010909 mm, the maximum equivalent stress is
0.57085 Mpa. Thus, the beam low order natural frequency is larger than the vibration
frequency of work, Dynamic stiffness is better, it won't produce resonance. When the
beam under extreme conditions, the maximum deformation is small, the static
stiffness is better. It will not affect the machining accuracy of deformation in the
work. The beam under extreme conditions of equivalent press is lesser, far less than
the yield limit of material of beam. But large mass makes the beam too bulky and
optimization design is necessary.
4 The Optimal Design of the Beam
Use shape Optimization module in ANSYS Workbench [7], and through the original
finite element model of beam to divide mesh, load the same boundary conditions and
loading in the static analysis, setting the Optimization goal mass reduction is 40%,
through iterative calculation, the optimization results are obtained as shown in figure
5. Use 3D software improve the finite element model of beam as shown in figure 6
Fig. 5. Topological optimization results
Advanced Science and Technology Letters Vol.121 (AST 2016)
128 Copyright © 2016 SERSC
Fig. 6. Beam after topology optimization
After optimization of beam of first-order natural frequency f=772.18 Hz, the
maximal displacement of beam is 0.0011189 mm, the maximum equivalent stress is
0.42119 Mpa, the mass is 204.37 kg, as shown in figure 7. The optimization results
show that beam mass reduce 14.8% after removing material, dynamic stiffness of
beam has increased, but the static stiffness is almost not change, the ability of
resistance to deformation and fracture is still strong.
(a) The displacement nephogram (b) Equivalent stress nephogram
Fig. 7. Static deformation picture
Use the beam which after topology optimize model input the ANSYS Workbench
of GDO module to optimize the sizes, the left plate and beam thickness as the design
variables, use the frequency, maximum displacement and maximum equivalent stress
as state variables, the minimum mass as objective function. Setting the left plate and
crossbeam of thickness is 35 to 60 mm, the largest displacement of beam
)mm002.0( maxmax , the maximum equivalent stress
)Mpa1( maxmax ), natural frequency
f( Hz770f ), through the interaction between various variables and iterative
calculation, we can get three optimal design points. From the candidates it can be seen
that the reasonable left plate thickness is 38~40mm, the crossbeam thickness about
48~50mm.Because the thickness of plate easy process after get round numbers, so in
the beam model, when the left plate is 40mm, beam thickness is 50mm, state variables
of beam satisfy boundary conditions that it get minimal mass. First order natural
frequency f=778.91Hz, the mass is 191.71kg, the maximal displacement is
Advanced Science and Technology Letters Vol.121 (AST 2016)
Copyright © 2016 SERSC 129
0.0010667mm and the maximum equivalent stress is 0.50217 Mpa. It can be
concluded that: after topology optimization, the maximal displacement of beam and
equivalent stress decreases, the first-order natural frequency increases, the rigidity get
better and the mass decreased by 13.3%. Through the left plate and crossbeam size
optimization, although the maximum equivalent stress increases, but the maximal
displacement reduced, stiffness can meet the demand of processing, and the mass is
decreased by 20.4%.
5 Summary
Based on finite element analysis of beam, it is concluded that the first order natural
frequency f=778.91Hz work is greater than the vibration frequency f=83Hz, the
maximum equivalent stress is 0.50217Mpa, which is far less than the allowable stress
of material. And the maximal displacement is only 0.0010667mm, which can meet the
accuracy requirement in the process of machining. The optimized structure mass is
decreased by 20.4%.
Acknowledgements. This topic of research is supported by National Natural Science
Foundation of China (Grant No. 51475366, 51475146) and Key Laboratory of
Scientific Research Projects of Shan'xi Educational Committee (Grant No. 12JS072).
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Advanced Science and Technology Letters Vol.121 (AST 2016)
130 Copyright © 2016 SERSC