TY - BOOK
T1 - Springback compensation of industrial parts with the displacement adjustment and springforward methods: Milestone 1
AU - Lingbeek, R.A.
PY - 2005
Y1 - 2005
N2 - One of the main problems for the deep-drawing process is springback. Generally,
the deep-drawing tools are directly derived from the shape of the product. However,
when the press is opened after forming, the product will spring back due to internal
stresses. In order to produce a geometrically accurate product, the geometry of the
tools is compensated. The goal of this project is to develop an algorithm to perform
this task automatically, with the use of FE deep-drawing simulations. In this report
the two main compensation algorithms are discussed that are mentioned in literature.
Springback compensation is always the last step in the process planning of a deep
drawn product. It is not always needed, in some cases the product can be made to
fit the assembly by simply pushing it back into the right shape. To make the right
decision, springback has to be measured and evaluated properly, which can be hard
for complex shaped products. Today, manual springback compensation is applied,
based on the measurements on prototype products. This is a time consuming process
for which a lot of experience is needed. The use of FE simulations can speed up this
process, but to fully use the detailed results of such a simulation, a compensation
algorithm has to be used.
The first algorithm is called the smooth displacement adjustment (SDA) method.
The method is based on a direct comparison of the desired shape and the shape after
springback. The idea is to compensate springback by reversing the springback deformation
field and applying this to the product geometry. The method can also be
applied iteratively by using the shape deviation field between the springback (actual)
geometry and the reference (desired) geometry. A smoothing/extrapolation function
has been added, so the new toolset can be derived directly from this compensated
product geometry. The method has been tested on a real industrial part, a trunk-lid
inner frame that has been adopted as a benchmark part for the NUMISHEET 2005
conference. The method was very successful, after compensation the mean shape
deviation was lowered by 70%. However, some large shape deviation was still present
in the product flanges, showing that there is still room for improvement.
The second algorithm is called the springforward (SF) method. The principle of
the SF method is to compensate springback with the internal stresses that cause
it, instead of applying direct geometric optimization, such as the DA method. The
method was applied to an academic process, the plastic bending of a strip. It is
explained that with the current definition of the algorithm, iterative application is
not useful. This problem is solved by adding a push-back stage, so the compensation
is linked to the desired geometry again. However, the actual calculation of the
compensated geometry suffers from large principal and numerical problems, as was
demonstrated using a simple industrial product.
1
AB - One of the main problems for the deep-drawing process is springback. Generally,
the deep-drawing tools are directly derived from the shape of the product. However,
when the press is opened after forming, the product will spring back due to internal
stresses. In order to produce a geometrically accurate product, the geometry of the
tools is compensated. The goal of this project is to develop an algorithm to perform
this task automatically, with the use of FE deep-drawing simulations. In this report
the two main compensation algorithms are discussed that are mentioned in literature.
Springback compensation is always the last step in the process planning of a deep
drawn product. It is not always needed, in some cases the product can be made to
fit the assembly by simply pushing it back into the right shape. To make the right
decision, springback has to be measured and evaluated properly, which can be hard
for complex shaped products. Today, manual springback compensation is applied,
based on the measurements on prototype products. This is a time consuming process
for which a lot of experience is needed. The use of FE simulations can speed up this
process, but to fully use the detailed results of such a simulation, a compensation
algorithm has to be used.
The first algorithm is called the smooth displacement adjustment (SDA) method.
The method is based on a direct comparison of the desired shape and the shape after
springback. The idea is to compensate springback by reversing the springback deformation
field and applying this to the product geometry. The method can also be
applied iteratively by using the shape deviation field between the springback (actual)
geometry and the reference (desired) geometry. A smoothing/extrapolation function
has been added, so the new toolset can be derived directly from this compensated
product geometry. The method has been tested on a real industrial part, a trunk-lid
inner frame that has been adopted as a benchmark part for the NUMISHEET 2005
conference. The method was very successful, after compensation the mean shape
deviation was lowered by 70%. However, some large shape deviation was still present
in the product flanges, showing that there is still room for improvement.
The second algorithm is called the springforward (SF) method. The principle of
the SF method is to compensate springback with the internal stresses that cause
it, instead of applying direct geometric optimization, such as the DA method. The
method was applied to an academic process, the plastic bending of a strip. It is
explained that with the current definition of the algorithm, iterative application is
not useful. This problem is solved by adding a push-back stage, so the compensation
is linked to the desired geometry again. However, the actual calculation of the
compensated geometry suffers from large principal and numerical problems, as was
demonstrated using a simple industrial product.
1
KW - IR-59604
M3 - Report
BT - Springback compensation of industrial parts with the displacement adjustment and springforward methods: Milestone 1
PB - Netherlands Institute for Metals Research
ER -