Computer Applications in Near Net-Shape Operations

by Nee, A. Y. C.; Ong, Say Kee; Wang, Y. G.

• ISBN13: 9781852331863
• ISBN10: 1852331860
• Format: Paperback
• Copyright: 1999-08-01
• Publisher: Springer Verlag

Summary

The process of producing components to final net-shapes is fast becoming a desirable goal for metal working industries. This is due to a combination of factors such as the development of new materials and escalating energy costs. Computer Applications in Near Net-Shape Operations addresses the design, analysis and simulation of near net-shape operations using some of the most advanced computer techniques and tools available. Topics covered include: Sheet metal forming operations: progressive stamping, fine blanking, nesting, flat pattering, bending and nibbling; Die design, construction and NC programming of wire EDM; Bulk metal forming processes such as cold upsetting and close-die forging; Injection mould design, analysis and simulation; Computer-aided design of CNC machines for near net-shape operations; Intelligent progressive die design system IPD. This collection of the latest developments from leading experts in the field will be of interest to practising engineers, graduate students and researchers of metal forming, stamping, mould and die design.

Table of Contents

List of Abbreviations	xv
List of Authors	xvii
Introduction to near net-shape operations	1	(6)
S.K. Ong
A.Y.C. Nee
Introduction	1	(1)
Classification of near net-shape operations	2	(3)
Sheet metal forming	2	(1)
Massive (bulk) metal forming processes	3	(1)
Injection moulding	4	(1)
Machines for near net-shape operations	4	(1)
Near net-shape operations: past, present and future	5	(2)
Bibliography	5	(2)
CAD/CAM for sheet metal forming and related processes	7	(88)
Z.G. Li
N.F. Choong
K.H. See Toh
H.T. Loh
A.Y.C. Nee
Introduction and basic techniques	7	(10)
Feature modelling of stampings	7	(6)
Application of expert systems to stamping die design	13	(4)
Optimisation of blank layout	17	(9)
Mathematical description of blank layout	18	(2)
The polygon method	20	(1)
The height function method	21	(5)
Fine blanking	26	(8)
Characteristics of the fine blanking process	26	(1)
Application of the fine blanking process	27	(1)
CAD/CAM of fine blanking dies	27	(7)
Progressive stamping	34	(15)
Software architecture of the system	35	(1)
Strip layout	36	(6)
Construction design of progressive dies	42	(7)
An overview of a flat patterning and bending simulation system	49	(15)
Design input module	49	(1)
Flat pattern development module	50	(1)
Bending simulation module	50	(1)
System details	51	(6)
Implementation of bending simulation module	57	(7)
CNC punching and nibbling	64	(12)
Computer-based system for CNC nibbling	64	(1)
Punch libraries	65	(1)
Profile classification	66	(1)
Punch selection and optimisation	67	(1)
An approach to automatic tool selection	68	(6)
A case study	74	(2)
Die construction design	76	(8)
Design of die and punch	76	(3)
Layout of ejectors	79	(5)
NC programming of wire EDM	84	(11)
Process consideration for NC programming of wire EDM	84	(1)
Geometric computation	85	(3)
NC programming procedure for wire EDM	88	(3)
References	91	(1)
Bibliography	92	(3)
CAD/CAM for massive (bulk) metal forming	95	(50)
J.C. Xia
Introduction	95	(2)
Cold upsetting	97	(19)
Determination of operations and sequences	97	(6)
Calculation of process parameters	103	(6)
Design of dies cavities, general parts and combined dies	109	(5)
The BNC CAD system	114	(2)
Closed-die forging	116	(29)
Selection and calculation of bars	116	(2)
Determination of operations and sequences	118	(8)
Calculation of forging load and stress	126	(5)
Design of dies	131	(9)
Program flowchart and description	140	(4)
References	144	(1)
CAD/CAE/CAM for injection moulding	145	(42)
D.Q. Li
X.G. Ye
Introduction	145	(3)
Brief history of development	145	(1)
Technological characteristics	146	(2)
Graphic input and geometry construction of injection moulded products	148	(3)
Wire-frame modelling	148	(1)
Surface modelling	149	(1)
Solid modelling	150	(1)
CAD for construction design of plastic injection moulds	151	(8)
Program flowchart	151	(1)
Standard mould base design	152	(3)
Cavity and core design	155	(1)
Runner bar design	156	(3)
Flow simulation of plastic injection moulding	159	(10)
One-dimensional flow analysis	159	(5)
Two-dimensional flow analysis	164	(1)
Three-dimensional flow analysis	165	(4)
Cooling simulation of plastic injection moulding	169	(7)
One-dimensional cooling analysis	169	(2)
Two-dimensional cooling analysis	171	(3)
Three-dimensional cooling analysis	174	(2)
CAM for plastic injection moulds	176	(8)
Integrated CAD/CAM system	177	(1)
Information transfer from CAD to CAM	178	(2)
Tool path generation in 2-D NC	180	(2)
Manufacturing for 3-D core and cavity	182	(2)
CAD/CAE/CAM system for plastic injection moulding	184	(3)
System configuration	184	(1)
CAD software functions	185	(1)
CAE software functions	185	(1)
CAM software functions	186	(1)
Bibliography	186	(1)
FEM applications in near net-shape operations	187	(64)
J.C. Xia
S.J. Li
Y.X. Ding
Introduction	187	(1)
FEM applications and developments in near net-shape operations	188	(18)
New algorithms for automatic triangular mesh generation	188	(7)
New algorithms for mesh rezoning in FEM simulation	195	(4)
Algorithms for generating isogram in FEM	199	(4)
Calculation of rigid regions using rigid-plastic FEM	203	(3)
FEM applications in massive (bulk) metal forming processes	206	(9)
Simulation of rigid-plastic finite element of radial extrusion process	206	(2)
Rigid-plastic finite element simulation of the upsetting-backward extrusion process	208	(5)
Simulation of forward extrusion and upsetting-backward extrusion process	213	(2)
FEM application in die design	215	(22)
Basic equations for FEM analysis of combined die and mathematical modelling of pre-stressing force	216	(3)
FEM solution and program flowchart	219	(3)
FEM analysis for combined backward extrusion die	222	(5)
FEM analysis for combined forward extrusion die	227	(4)
FEM analysis for precision forging die for blades	231	(3)
Optimisation design of combined dies	234	(3)
FEM application in analysis of hydraulic presses	237	(14)
Finite element analysis of fluid transients	237	(3)
Non-symmetrical frontal solution method for fluid FEM	240	(10)
References	250	(1)
CAE/CNC of machines for near net-shape operations	251	(14)
Y.G. Wang
Q.Z. Yang
Introduction	251	(1)
Universal CNC systems for near net-shape operations	252	(4)
Composition of universal CNC control system	252	(1)
Intelligent control module board	253	(1)
Module of control software	254	(1)
Communication in an integrated-distributed CNC system	254	(2)
CNC for sheet metal forming machines	256	(3)
CNC system for shearing machines	256	(1)
CNC system for press brakes	257	(2)
FMC for sheet metal bending	259	(6)
CNC and automatic generation of system software	259	(3)
Bending design based on features	262	(1)
Manufacturability criteria for sheet metal bending FMC	262	(2)
Bibliography	264	(1)
IMOLD®: an intelligent mould design and assembly system	265	(20)
Y.F. Zhang
J.Y.H. Fuh
K.S. Lee
A.Y.C. Nee
Introduction	265	(1)
Injection moulding	265	(1)
Computer applications in injection mould design	266	(1)
IMOLD®	267	(6)
IMOLD® functional modules	268	(5)
Design information management in IMOLD®: assembly tree	273	(1)
An example	273	(10)
Conclusions	283	(2)
References	284	(1)
Computer applications in intelligent progressive dies design (IPD)	285	(30)
B.T. Cheok
A.Y.C. Nee
Introduction	285	(1)
Overview of the computer architecture	285	(2)
Advanced knowledge-based techniques for the modelling and generation of progressive dies	287	(8)
A model-based reasoning (MBR) approach for die design	287	(4)
Shape representation and spatial reasoning techniques	291	(2)
A function-spatial language for the configuration of a die	293	(2)
An industrial case study	295	(13)
Introduction	295	(1)
Description of stamping	295	(1)
Features of the part	295	(1)
Modelling the part	296	(2)
The flat pattern	298	(1)
The strip layout	299	(1)
3-D strip layout	300	(3)
Configuration of the progressive die	303	(4)
Technical data generated by the system	307	(1)
Conclusions	308	(7)
Bibliography	310	(5)
Index	315