Title Unaprjeđenje procesa inkrementalnog preoblikovanja u jednoj točki : doktorska disertacija
Title (english) Furthering the process of single point incremental forming
Author Marko Kršulja
Mentor Zlatan Car (mentor)
Mentor Tomaž Pepelnjak (komentor) strani drzavljanin: .
Committee member Miljenko Math (predsjednik povjerenstva)
Committee member Josip Brnić (član povjerenstva)
Committee member Miroslav Plančak (član povjerenstva) strani drzavljanin: .
Committee member Zlatan Car (član povjerenstva)
Committee member Tomaž Pepelnjak (član povjerenstva) strani drzavljanin: .
Granter University of Rijeka Faculty of Engineering Rijeka
Defense date and country 2013-09-02, Croatia
Scientific / art field, discipline and subdiscipline TECHNICAL SCIENCES Metallurgy
Universal decimal classification (UDC ) 669 - Metallurgy
Abstract U ovome je radu proveden niz istraživanja kako bi se utvrdio stabilni tehnološki proces izrade
tankostjenih proizvoda tehnologijom inkrementalnog oblikovanja u jednoj točki (SPIF - single
point incremental forming). Pretpostavljeno je da je moguće primijeniti tehnologiju
inkrementalnog oblikovanja na tankostjeni lim. Istraživanja su provedena na čeličnome limu
TS230 (broj čelika prema EN 10027-2 je W. nr. 1.0371) debljine 0,155 mm i na limu TH415
(broj čelika prema EN 10027-2 je W. nr. 1.0377) debljine 0,24 mm s ciljem utvrđivanja
optimalnih parametara u njihovoj obradi SPIF tehnologijom. Provedena su ispitivanja
mehaničkih svojstava s ciljem utvrđivanja pouzdanosti ulaznih parametara kako bi se jasno
definirala točnost izrade tražene geometrije krnjeg stošca pomoću SPIF procesa. Proveden je
vlačni test kako bi se definirao konvencionalni dijagram naprezanje - deformacija, te Marciniak
test kako bi se formirao dijagram deformabilnosti SPIF tehnologijom. Postavljeni su analitički
modeli koji opisuju stanjivanje lima, kritične sile te pojavu trenja za ispitivane limove u SPIF
procesu. Prema rezultatima analitičkog modela za izračun sile u SPIF procesu za tankostjene
limove provedeno je ispitivanje trenja za odabrane materijale TS230 i TH415. Uzimajući u obzir
rezultate vlačnoga testa i ispitivanja trenja postavljeni su uvjeti za modeliranje, analizu i
simulaciju SPIF procesa u softveru ABAQUS. Za izradu modela odabran je oblik krnjeg stošca,
simulacije su provedene kako bi se utvrdili uvjeti izrade uspješnog SPIF procesa za materijal
TS230 i TH415. Na temelju prikupljenih podataka postavljen je plan eksperimenata za
istraživanje u realnim proizvodnim uvjetima te je pristupljeno eksperimentalnoj verifikaciji
modela. Odabran je CNC stroj, CNC-glodalica WEMAS VZ 750, te je projektirana specijalna
radna naprava te su odabrani alati za inkrementalno oblikovanje. Postavljeni su modeli za
izvedbu SPIF procesa na odabranom stroju pomoću softvera Solidcam i VeriCUT. Prema
dobivenim spoznajama izveden je eksperimentalni plan izrade krnjeg stošca kako bi se utvrdilo
funkcioniranje modela. Nakon uspješno izvedenog SPIF procesa i utvrđivanja optimalnih
parametara obrade, postavljen je eksperimentalni plan mjerenja stanjivanja lima, ponovljivosti
oblika te sposobnosti izvedenog inkrementalnog oblikovanja. Sposobnost inkrementalnog
oblikovanja tankostjenog lima mjerena je metodom 3D fotogrametrije (digitalizacijski sustav
ARGUS), a dobiveni su rezultati uspoređeni sa dobivenim rezultatima Marciniak ispitivanja.
Sustavom 3D fotogrametrije kontrolirana je ponovljivost oblika i stanjivanje tankostjenog lima.
Ustanovljena je maksimalna sposobnost inkrementalnog oblikovanja za ispitivane materijale s
oblikom krnjeg stošca. Objašnjeni su parametri koji uvjetuju uspješnu obradu SPIF procesom
tankostjenog materijala. Izvršena su dodatna mjerenja tvrdoće, hrapavosti i topline.
Abstract (english) In this work series of investigations were conducted in order to establish a stable technological
process of manufacturing tinplate products with single point incremental forming technology
(SPIF). In beginning of investigation it was assumed that SPIF technology is applicable on thin
sheet metal. Investigations were conducted on two materials steel tinplate TS230 (W. nr. 1.0371
according to EN 10027-2) thickness of 0.155 mm and steel tinplate TH415 (W. nr. 1.0377
according to EN 10027-2) thickness of 0.24 mm with the goal of establishing optimal parameters
in their manufacture with SPIF technology. Investigation of mechanical properties will be
conducted with the goal to establish reliable input parameters in order to clearly define the
accuracy of investigated truncated cone dimensions with SPIF process. A tensile test was
conducted in order to define material stress - strain curve and Marciniak investigation in order to
create forming limit diagram (FLD) for SPIF technology. Analytical models were defined in
order to describe effect of sheet metal thinning, defining critical force and friction for
investigated sheet metal in SPIF process. Friction investigation was conducted for materials
TS230 and TH415 according to results obtained from analytical model for defining critical
forces in SPIF process for thin sheet metals. Considering obtained results of tensile and friction
investigation conditions for modelling, analysis and simulation of SPIF process in ABAQUS
software are obtained. A truncated cone was selected for model development, a series of
simulations were conducted in order to establish conditions for successful SPIF process of
selected materials TS230 and TH415. On the basis of collected data a plan of experiments for
real production conditions was proposed and verification of proposed was conducted. The CNC
machine, CNC milling machine WEMAS VZ 750 was selected, the special work holder and
tooling necessary for SPIF process proposed and created. Models for execution of SPIF process
on milling machine were selected with softer Solidcam and VeriCUT. According to acquired
know-how an experimental plan for creation of truncated cone was executed in order to confirm
functionality of developed model. After successful execution of SPIF process and confirmation
of optimal working parameters an experimental plan was prepared in order to measure with 3D
fotogrametry. Thinning of sheet metal, geometry shape repeatability and FLD were measured
with 3D fotogrametry system ARGUS. FLD diagrams for material TS230 and TH415 for
selected geometry shape of truncated cone was defined. Obtained FLD diagrams of SPIF process
ware compared with obtained FLD diagrams of Marciniak investigation. Explanation of
influential parameters that influence successful SPIF process of thin sheet metal is given.
Additional measurements of hardness, roughness and heat were conducted.
Keywords
inkrementalno oblikovanje metala
deformiranje
CNC stroj
kontrola procesa
mjerenje
3D fotogrametrija.
Keywords (english)
Incremental metal forming
deformation
CNC machine
process control
measurement
3D fotogrametry.
Language croatian
URN:NBN urn:nbn:hr:188:528992
Project Number: 069-1201787-1754 Title: Numeričko modeliranje, simulacija i optimizacija u oblikovanju lima Jurisdiction: Croatia Funder: Ministarstvo znanosti
Study programme Title: Postgraduate university (doctoral) study Study programme type: university Study level: postgraduate Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
Catalog URL http://libraries.uniri.hr/cgi-bin/ucat/unilib.cgi?form=D1130410083
Type of resource Text
Extent 171 str
File origin Born digital
Access conditions Open access
Terms of use
Created on 2017-01-19 18:27:26