Research Article Open Access
Dametew and Gebresenbet, J Material Sci Eng 2017, 6:5
DOI: 10.4172/2169-0022.1000382
Research Article Open Access
Journal of Material Sciences & Engineering
J
o
u
r
n
a
l
o
f
M
a
t
e
r
i
a
l
S
c
i
e
n
c
e
s
&
E
n
g
i
n
e
e
r
i
n
g
ISSN: 2169-0022
Volume 6 • Issue 5 • 1000382 J Material Sci Eng, an open access journal
ISSN: 2169-0022
Study the Effects of Spring Back on Sheet Metal Bending using
Mathematical Methods
Dametew AW
1
* and Gebresenbet T
2
1
School of Mechanical Engineering, Kombolcha Institute of Technology, Wollo University, Germany
2
Industrial Engineering, Saint Mary's University, San Antonio, Texas USA
Abstract
In this study mathematical analysis of spring back was done for optimization of sheet metal bending process. The
infuence of sheet metal thickness, sheet metal type, friction, tool radius and tool shape on spring back for Aluminium,
copper, mild steel and High strength steels, sheet metal have been used as variable to conducted this study. Since,
the effects of each variable on the formation of spring back on sheet metal forming are investigated the following way.
This empirical result shows that increasing sheet metal thickness from 0.8 mm to 4.5 mm the spring back is reduced
16% and 20.35%. When increasing of sheet metal strength spring back increases because spring back of the sheet
should depend on the yield strength of the material. As the materials yield strength increase the spring back after
un-loading condition also increases. The effects of material type as shows that, using Aluminium sheet metal instead
of high strength sheet metals spring back is reduced by 56.%. Also, for decreasing of the tool radius leads reducing
spring back. Spring back of deferential die 12% lower than edge bending die. In addition to these, if increasing the
friction coeffcient from 0.01 to 0.50 the spring back also increases by 52% because of increasing of friction force and
this force generates higher amount of spring back. Thus the effects of material type, tool geometry, working condition
and the thickness of sheet metal types were studied and investigated. Since, ultimately utilizing and compensation of
tool is considered for prevention of spring back and optimizing of sheet metal bending process as well.
*Corresponding author: Alie Wube Dametew, Technische Hochschule Nurnberg
Georg Simon Ohm Nürnberg, Germany, Tel: +251913032751; E-mail:
wubealie@gmail.com
Received September 15, 2017; Accepted October 16, 2017; Published October
26, 2017
Citation: Dametew AW, Gebresenbet T (2017) Study the Effects of Spring Back on
Sheet Metal Bending using Mathematical Methods. J Material Sci Eng 6: 382. doi:
10.4172/2169-0022.1000382
Copyright: © 2017 Dametew AW, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
Keywords: Sprint back; Sheet metal; Banding process; Efects;
Mathematical analysis; Optimization; Variables and efects
Introduction and Back Ground
Sheet metal bending is one of the most widely applied sheet metal
forming operations. According to Prabhakar, et al. [1] bending of
sheet metal is one of the widely used in industrial process, especially
in automobile and aircraf industries, sheet metal bending is one
of the most widely applied sheet metal forming operation. Te
bending process includes larger deformation of the structure either
with temperature or without temperature application. But in the
every mechanical process certain defects exists due to the inherent
resistance property of the material for forming it to the required shape.
Although the bending processes are accompanied by strains that are
due to the instability phenomena which accompany the processing.
Tese instability phenomena occur during the bending process (the
cracking, deformation, the breakage) as well as afer the bending
process (the bowing). Tough, one type of defect is spring back and
is very important phenomenon which makes the object non suitable
in case of rigid requirements. Spring back is mainly due to Bauchigner
efect which allows the material to follow diferent paths during loading
and unloading cycles. On the other hand Quality and success of the
bending product depends upon the operating parameters as well as,
material properties, material type, working condition, clearance,
geometry of the die and punch, friction condition etc. In ancient times,
sheet metal bending processes and bending quality are dependent on
the designer's experience and involve trials and errors to obtain the
desired result. All forming process will take places in the plastic region.
So to analyze or to estimate spring back, nonlinear material properties
which will accommodate stress strain relations in the nonlinear regions
are required.
Many analytical models are proposed to study spring back in
bending by using simple beam or plate bending and these models use a
simplifed assumption.
Spring back is a main defect occurred in the sheet-metal forming
processes and has been thoroughly studied by researchers. Te
prediction of spring back has challenging for a variety of reasons,
including numerical sensitivity, physical sensitivity, and poorly
characterized material behavior under reverse loading and unloading
conditions. In the previous time, quite a few eforts have been made
to obtain a deep understanding of the spring back phenomenon. But
till now the problem of spring back on sheet metal product is there.
However this study is intended to analysis the efect of spring back
using mathematical analysis, by considering tool geometry, material
type, friction condition , working condition and sheet metal type were
considered so as to improve spring back efect and optimize sheet metal
bending process.
Research Methodology
In this study from the beginning to accomplishing result and till
to reach the conclusion, the study was conducted through Empirical/.
mathematical analysis from the data was collected primary source,
literature review of research articles, books, magazines, manuals,
company report and electronic-sources which are discuss related to
bending process, sheet metal forming, sheet metal forming variables,
the efects and science of spring back and mechanics of sheet metal
forming process. Since, the study considered attempts to explore,
analysis and discuss the efects of sheet metal type, sheet metal