- Type of paper
: Paper in book
Title: FLOW FORMULATION OF FINITE ELEMENT SIMULATION OF FORMING
OF STRAIN HARDENING MATERIALS
- Authors:
- Vučina, Damir (129716)
- Editors
- Owen, D.R.J.
- Onate, E.
- Hinton, E.
Publisher: Pineridge press
Year: 1992
Pages: from 1185 to 1196
Number of references: 16
Language: engleski
Summary: Computational plasticity finds one major application in
metalforming simulations. In analysis of stationary formingprocesses, flow
formulation with veleocity field variables provesvery convenient.
Corresponding finite element algorithms veryefficiently yield strain rate
and stress distributions forcomplex viscoplastic constitutive equations. In
this paper theclassical flow formulation is extended to cases where
thematerial constitution is a nonlinear function of booth strain andstrain
rate. A finite element level this extension requires thedetermination of
the trajectory of each numerical integrationbase point in the problem
domain for the purpose of strain rateintegration. Corresponding 2D finite
element procedures have beendeveloped and applied to the idealized cold
rolling process.
Keywords: Flow formulation, finite elements, simulation, strain hardening materials
- Type of paper
: Paper in book
Title: FEM SIMULATION OF PLASTIC FLOW WITH BOUNDARY FRICTION AND
STRAIN HISTORY
- Authors:
- Vučina, Damir (129716)
- Editors
- Chenot, J.L.
- WOOD, R.D.
- Zienkiewicz, O.C.
Publisher: A.A.Balkema
ISBN: 90 5410 087 7
Year: 1992
Pages: from 681 to 686
Number of references: 12
Language: engleski
Summary: In this paper the flow formulation viscoplastic finite
element analysis is applied to metal forming problems where the material
constitutive equations are functions of both strain rate and strain
history. The numerical procedures developed include determination of the
particular trajectory that the strain rate is integrated along, for each
numerical integration base point. Boundary friction is taken into account
by developing interface elements that directely generate the frictional
traction at particular boundary nodes, or impose Coulomb friction
conditions as constrains at node or edge level using the penalty funcion
approach. Corresponding 2D finite element routines have been developed and
applied to idealized cold plane extrusion and other metal forming
processes.
Keywords: FEM simulation, plastic flow, boundary friction, strain history
- Type of paper
: Paper in proceedings
Title: CONSTITUTIVE MODELS OF MATERIAL AND OVERLAY METHOD IN FLOW
FORMULATION
- Authors:
- Vučina, Damir (129716)
- Lozina, Željan (96925)
Proceedings title: 7. Jugoslavenski simpozij o teoriji plastičnosti
Language: hrvatski
Place: Pula
Year: 1991
Pages: from 83 to 88
Meeting: 7. JUGOSLAVENSKI SIMPOZIJ O TEORIJI PLASTIČNOSTI
Held: from 11/11/91 to 11/11/91
Summary: In this paper aseveral constitutive models of material for
analysis of viscoplastic metal flow by the finite element method are
developed. Composition of models is derived by technique of overlaying of
mechanical eqvivalents at the level of models.
Keywords: Constitutive models, overlaying, flow formulation
- Type of paper
: Paper in proceedings
Title: MODELLING OF COLD METAL FORMING PROCESSES
- Authors:
- Duplančić, Igor (10940)
- Lozina, Željan (96925)
- Vučina, Damir (129716)
- Lazinica, Živko (58791)
- Baletić, Frane (186183)
- Đukić, Predrag (186146)
Proceedings title: 37. međunarodni godišnji skup KoREMA
Language: engleski
Place: Zagreb
Year: 1992
ISBN/ISSN: 86-81571-11-7
Pages: from 103 to 106
Meeting: 37. Međunarodni godišnji skup KoREMA
Held: from 04/26/92 to 04/29/92
Summary: The flow formulation with velocity field variables is very
convenient and efficient for the finite element simulation of many metal
forming processes. An original software system is developed for simulation
of metal forming processes in the rigid- plastic FE formulation. Complex
constitutive material models are composed by overlaying of simple material
models. The finite element procedure used here includes the determination
of the particular trajectory for each base point within the viscoplastic
deformation zone. Due to material constitution nonlinearity the whole
algorithm is iterative. Several distribution of equivalent strain, strain
rate and stress within deformation zones for processes of rolling and
extrusion are obtained.
Keywords: Modelling, cold metal forming
- Type of paper
: Paper in proceedings
Title: INSTRUMENTALISATION OF MANUALLY CONTROLED HYDRAULIC PRESS
- Authors:
- Đukić, Predrag (186146)
- Lozina, Željan (96925)
- Vučina, Damir (129716)
- Duplančić, Igor (10940)
Proceedings title: 37. Međunarodni godišnji skup KoREMA
Language: hrvatski
Place: Zagreb
Year: 1992
ISBN/ISSN: 86-81571-11-7
Pages: from 175 to 178
Meeting: 37. Međunarodni godišnji skup KoREMA
Held: from 04/26/92 to 04/29/92
Summary: For the purpose of eksperimental analysis
instrumentalisation of existing, manually controlled hydraulic press is in
progress. For automatic asquisition, processing and storage of measured
values electronic computer would be used. As a first step functional model
of electric part of equipment for measuring of displacement and forces in
movable parts of press is made. Functional model enables graphic display of
measured values in real time.
Keywords: Instrumentalization, hydraulic press
- Type of paper
: Paper in proceedings
Title: TRENDS IN METAL FORMING RESEARCH
- Authors:
- Duplančić, Igor (10940)
- Vučina, Damir (129716)
- Lozina, Željan (96925)
- Editors
- Cebalo, Roko
Proceedings title: Suvremeni trendovi proizvodnog strojarstva
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 1 to 8
Meeting: Suvremeni trendovi proizvodnog strojarstva
Held: from 05/05/92 to 05/05/92
Summary: In this paper a survez of current research in metal forming
area is given. Included are investigations of forming processes of metal,
metal powder and composite materials using the finite elements method. The
results of the present analysis may give directions for future research in
metal forming.
Keywords: Metal forming, finite elements
- Type of paper
: Paper in proceedings
Title: EFFECT OF PROCESS PARAMETERS ON THE PROPERTIES OF AlMgZn
ALLOY EXTRUDED HOLLOW SHAPES
- Authors:
- Duplančić, Igor (10940)
- Prgin, Jere (68474)
- Editors
- Werner, Robert I.
Proceedings title: Proceedings of 5th International Aluminum Extrusion Technology Seminar
Language: engleski
Place: Chicago, USA
Year: 1992
Pages: from 559 to 570
Meeting: 5th International Aluminum Extrusion Technology Seminar
Held: from 05/19/92 to 05/22/92
Summary: This work presents a procedure for the production of
AlZnMg(7000) aluminum alloy thick walled hollow shapes using bridgedies.
Tests were performed on a 50 MN extrusion press. The influence of weld
chamber geometry, billet material, and heat treatment on the properties of
the extruded shapes was observed.The better quality of longitudinal welds
of hollow shapes can be achieved using material and process parameters
which produce a fine grain structure. The height of the weld chamber has a
significant influence on extrusion pressure and therefore on the tensile
and bending strength of the welds.
Keywords: Extrusion, AlZnMg aluminum alloy, hollow shapes, bridge dies
- Type of paper
: Paper in proceedings
Title: METAL FLOW IN WELD POCKET AND HOLLOW DIES
- Authors:
- Mioč, Miho
- Duplančić, Igor (10940)
- Editors
- Dalla Barba, W.
Proceedings title: Aluminium 2000
Language: engleski
Place: Modena, Italija
Year: 1993
Pages: from 367 to 387
Meeting: 2nd International congress on aluminium 1993.
Held: from 03/30/93 to 04/04/93
Summary: The paper discusses our experience in design and control of
metal flow in weld pocket and hollow dies. Special attention is paid to the
weld pocket design used for production of solid shapes. Weld pockets are
now of the great interest since the use of pullers on extrusion presses has
been predominant lately. Various types of hollow dies are available for
production of hollow sections. The selection of the die type and die
geometry is a difficult task for a die designer. Metal flow is more complex
then in the flat dies. It can be controlled on several places at the
entrance, in the channels and weld chambers, as well as on the exit side of
the hollow die.
Keywords: Metal flow, Weld pocket die, hollow die
- Type of paper
: Paper in proceedings
Title: COLD FORMING OF STEELS
- Authors:
- Duplančić, Igor (10940)
- Baletić, Frane (186183)
- Kotarac, Ivan
- Editors
- Mamuzić, Ilija
Proceedings title: Materijali i metalurgija
Language: hrvatski
Place: Sisak
Year: 1993
Pages: from 0 to 0
Meeting: Simpozij hrvatskih metalurga
Held: from 09/15/93 to 09/17/93
Summary: Process sequence design in cold metal forming always
represent a major task for each designer. This work describes and analyses
procedure which is used for manufacturing of boolts M10x30 mm. All
operations starting from raw material to final shape of bolt are discussed.
Special attention is paid to cold forming operations, in which the rules
for forming sequence design are presented.
Keywords: forming of steels, cold forming
Other: Skup je zbog ratnih neprilika u Sisku održan u veljači
1994.godine.
- Type of paper
: Paper in proceedings
Title: FLOW FORMULATION FE ANALYSIS WITH PENALIZED BOUNDARY
FRICTION
- Authors:
- Vučina, Damir (129716)
Proceedings title: 7th International Conference on Mechanical Behaviour of Materials
Language: engleski
Place: Hague, Netherlands
Year: 1995
Pages: from 426 to 428
Meeting: 7th International Conference on Mechanical Behaviour of Materials
Held: from 05/28/95 to 06/02/95
Summary: In standard, materially-nonlinear flow formulation analysis
of stacionary viscoplastic metal forming problems, the viscosity term is
evaluated in the problem domain as a function of strain-rate. The objective
of this paper is to extend the applicability of this approach to strain
history sensitive materials and boundary interfaces with friction.
Keywords: flow formulation, FE analysis, boundary friction
- Type of paper
: Paper in proceedings
Title: MODELLING OF BOUNDARY FRICTION WITH THE PLASTIC FLOW
FORMULATION FINITE ELEMENT ANALYSIS
- Authors:
- Vučina, Damir (129716)
Proceedings title: Zbornik radova 1. kongresa hrvatskog društva za mehaniku
Language: hrvatski
Place: Pula
Year: 1994
Pages: from 203 to 211
Meeting: 1. Kongres hrvatskog društva za mehaniku
Held: from 09/14/94 to 09/17/94
Summary: Numerically efficient modelling of the boundary layer with
friction is one of the basic problems in analysis of metal forming
processes. In this paper, numerical procedures which involve inserting a
layer of interface elements are developed for the flow-formulation
viscoplastic FE analysis. These elements generate additional load or impose
the friction law as a costraint via penalty function. In both cases, the
friction force is modelled as a function of the velocity field for
numerical stability and convergence of the complete iterative process. The
results obtained with both approaches are compared on the simulation of the
cold extrusion process.
Keywords: boundary friction, FE analysis, viscoplastic flow-formulation
- Type of paper
: Summary in proceedings
Title: MODELLING, SIMULATION AND OPTIMIZATION OF METAL FORMING
PROCESSES
- Authors:
- Duplančić, Igor (10940)
- Lazinica, Živko (58791)
- Lozina, Željan (96925)
- Vučina, Damir (129716)
- Baletić, Frane (186183)
- Đukić, Predrag (186146)
Proceedings title: 3. Međunarodni simpozij o novim tehnologijama
Language: hrvatski
Place: Opatija
Year: 1991
ISBN/ISSN: UDK621.7:519.
Pages: from 24 to 24
Meeting: 3. Međunarodni simpozij o novim tehnologijama
Held: from 10/15/91 to 10/17/91
Summary: As a part of the project mathematical models and
corresponding software routines for analysis and simulation of metal
forming processes are being developed. The finite element method in the
flow formulation for nonlinear constitutive models is used.
Keywords: modelling, simulation, optimization, metal forming processes
- Type of paper
: Ph.D.
Title: CONTRIBUTION TO MODELLING OF VISCOPLASTIC METAL FLOW BY
THE FINITE ELEMENT METHOD
Faculty: strojarstva i brodogradnje ZAGREB
Author: VUČINA DAMIR
Date of defense: 12/29/93
Language: hrvatski
Number of pages: 177
Summary: The theoretical concepts of continuum mechanics, the theory
of plasticity and the solid formulation and flow formulation are
demonstrated. The basic concept and expressions of the flow formulation
theory are upgraded by originally developed procedures and expressions for
determination of the strain history. In order to mathematically describe
the boundary layer between the material and surrounding, specific numerical
procedures are originally developed to include the boundary friction.
Original mathematical expressions and corresponding elements are derived
for direct generation of the frictional traction in the boundary nodes.
Alternatively, elements that impose boundary friction conditions in the
original formulationas penalized constrains are derived. The expressions
derived are further elaborated in the form of numerical algorithms and
materialized as an original program package. Several metal forming
processes are numerically simulated and are compared with those available
in literature.
Keywords: modelling, viscoplastic metal flow, finite element
