Hardik Shah1, Prof. S.C. Chaudhary2 1M.E.
2 Assistant
Production Engineering student (En No.140390728006), Professor, Mech. Dept. S.P.B. Patel Engineering Engineering College, Linch - Mehsana Mehsana
Introduction
Sr.
Parts
Size
Parametric Analysis
• Conventional Conventional Sheet forming process process is very costly as higher costs are involved in hydraulic punch-press &
1. 2.
Frame Basepla Baseplate te
300 x 300 x 10mm 30 300 0 x300 x 10m 10mm m Height 150 mm Width 10mm length length 200mm
Analysis of variance for Surface Roughness
die. • Incremental Incremental sheet forming eliminates eliminates major cost of die
and hydraulic punch press. press. Also called die-less forming
3.
Column
4.
Bolt
No. A B C Error
M12
• CNC motion with pre-defined tool path and CAD design
of desired product are main components components of process process which utilizes round ball ended tool to form sheet into desired product.
No.
Dia.
1.
8 mm
2.
• Process Process paramet parameters ers like step step depth, depth, Wall Wall angle angle &
3.
spindle speeds are optimized for ISF process.
Material
PROCESS PARAMETER Wall Angle Step depth Spindle Speed
VARI ARIANC ANCE E F TEST TEST 0.9884 3.7506 0.455 0.6295
1.57 5.96 0.72 1
% OF CONTRIBUTION 16.97% 64.40% 7.81% 10.81%
Analysis of variance for Wall Thickness
SS304 10 mm length: 12mm 150 mm
No.
Experimental procedure Basic arrangement arrangement for ISF process
PROCESS PARAMETER
VAR ARIA IANC NCE E F TES TEST T
% OF CONTRIBUTION
A
Wall Angle
0.26948
173.243
99.46%
B
Step depth
0.00062
4
0.23%
C
Spindle Speed
0.00068
4.43
0.25%
0.00015
1
0.06%
Error
Surface Roughness
• NC motion control
• Blank holder
• Predefined tool path
• Forming sheet of required
• Round – ball ended tool
Wallthickness
thickness.
Literature Review • Filice & Park (2002) concluded that the crack occurs
mostly mostly at the corners, corners, since since the deformatio deformation n at the corner is greater than that of along the sides. • Jeswiet (2006) studied incremental forming of AA3003. Faster Faster spindle spindle rotatio rotation n speeds speeds improve improved d the sheet sheet formability formability significantly significantly.. Tool diameter has negligible negligible effect on the likelihood of forming a part.
• In Incremental Incremental sheet forming process, process, 3D shapes are
formed formed from from sheet sheet metal metal using using simple simple rotating rotating tool moving downwards along defined path on the sheet surface by progression of localized plastic deformations
• Durante (2009) in an investigation investigation on spindle speed
• The proces process s starts starts from from a flat sheet metal blank,
evaluated the surface roughness of the formed sheets. ANOVA tables were observed observed to be satisfactory satisfactory to identify whether a process process variable variable exerts significant significant
clamp clamped ed on a suffic sufficie ient ntly ly stiff stiff blank blank holde holderr and mounted on the table of a CNC • Hemispheri Hemispherical cal tool is inserte inserted d in tool tool holder holder.. Tool
influence on the process or not. • Kurra Suresh (2013) (2013) reported that the tool path has a
signific significant ant effect effect on dimensi dimensiona onall accura accuracy cy,, surface surface roughness, processing time and thickness variation. • Arfa (2013) in his investiga investigation tion on the tool forces required required to deform plastically plastically the sheet concluded concluded that the the nume numeric rical al simula simulatio tion n might might be explo exploite ited d for optimization of the incremental forming process • Har Harsh shal al
& Desh Deshmu mukh kh (201 (2014) 4),, in a rev review iew on optimization optimization techniques during sheet metal forming, have stated that one of the most widely used methods is Gray RelationalAnalysis (GRA)
Process Parameters INPUT PARAMETERS
OUTPUT PA PARAMETERS
S PI PI ND ND LE LE SP SP EE EED (I (I N RP M) M)
S UR URFAC E RO UG UGH NE NESS
WALL AN ANGLE (IN DE DEGREE)
WALL TH THICKNESS
STEP DEPTH (IN MM)
moves on the predefined tool path by CNC to form desire desired d shape shape with progres progressiv sive e increme increment nt of step depth.
Step Sr. Wall Angle Depth No. (degree) (mm) 45 0.2 1 45 45 55 55 55 65 65 65
0.5 1 0.2 0.5 1 0.2 0.5 1
RESPONSE
Spindle Speed (rpm) 800
Surface Roughness (μm) 4.87
1000
4.36
600 1000 600 800 600 800 1000
6.69 4.11 4.76 5.02 4.02 4.18 5.54
Thickness (mm) 1.16 1.17 1.19 0.73 0.77 0.75 0.98 0.97 0.99
Force Calculations & FLD Forming Limit Diagram
Step Step dep depth th are are
found found
the most most
significant significant effect on surface roughness. roughness. Increase Increase in spindle spindle speed rate, rate, value value of surface surface roughn roughness ess is
surface roughness. Wall thickness • The volume of material material deformed deformed can be achiev achieved ed
better better when when machini machining ng was done at medium medium Step Step depth and small wall angle. • Wall angle is found the most significant significant effect on Wall
thickness. Increase in wall angle value,Wall thickness increases in between and after that Wall thickness is decreases with increase in wall angle.
References 1) Amar Amar Kumar Behera Behera & path path
comp compen ensa sati tion on
Joost Joost R Duflou 2013, 2013, ‘Tool
stra strate tegi gies es
for for
SPIF SPIF
usin using g
multivariate multivariate adaptive adaptive regression regression splines ’, Computer Aided Design, Design, vol.45, vol.45, pp.575 pp.575 –590
Experimental Specification • A squa square re blank blank of appro approx. x. 100 mm X 100 100 mm X 1.22mm size is used on 3-axis CNC milling machine. • Fixture is used to hold blank made from mild steel. • Hemisph Hemispheric erical al tool used used is 10 mm in diamete diameterr and length will be 150 mm made from SS304. • Varying wall angle pyramidal frustums are formed. • Sample pyramidal geometries geometries are modelled with top base is a square of side 100 mm and 30 mm depth with defined wall angle
• Wall Wall angle angle and and
• Spindle speed speed are found to have very least effect on
Design of Experiment & Results
3 4 5 6 7 8 9
Conclusion Surface roughness:
decreases up to 0.2 micron after that it increases.
PROCESS PARAMETERS
2
In multi response response optimization the optimum parameter parameter combi combina natio tion n for for incre increme menta ntall form forming ing is meet meeting ing at experim experiment ent 6 and its paramet parameter er value value is 600 rpm/min spindle Speed and 0.5 mm depth of cut, for a wall angle of 45 0.
2) Kur Kurra ra Sure Suresh, sh, Arman Arman Khan Khan & Srini Sriniva vasa sa Praka Prakash sh Regalla 2013, ‘Tool Path Definit Definition ion for Numerica Numericall Simulati Simulation on of Single Single Point Point Increm Incrementa entall Forming’, Procedia Engineering, vol.64, pp.536 –545. Major strain = (major axis length – original circle dia.) x100 Original circle dia. Minor strain = (minor axis length – original circle dia.) x100 Original circle dia.
3) Skjo Skjoed edtt & M.Silv M.Silva, a, 2007 2007 ,‘Single point incremental incremental forming using a dummy sheet’, Proce Proceedin edings gs of Second ICNFT Bremen, Germany, pp.267 –276.
the
