Jedan Prikaz Okruzenjapri Procesu Konstruisanja

7/29/2019 Jedan Prikaz Okruzenjapri Procesu Konstruisanja

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Ma{instvo 4(2), 169 - 182, (1998) N.Rep~i}: JEDAN PRIKAZ OKRU@ENJA...

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JEDAN PRIKAZ OKRU@ENJA PRIPROCESU KONSTRUISANJA

Prof.dr.NedàdRep~i},Ma{inskifakultetuSarajevu,UniverzitetuSarajevu,71000Sarajevo,Vilsonovo{etali{te9,BosnaiHercegovina,REZIME

Ovaj rad je jedan prikaz dizajn okruènja, koji poku{ava adresirati problem integrativnog alata u procesukonstruisanja. Porast kompleksnosti proizvodnog procesa i potrebe za vi{om efikasnosti, ve}om fleksibil-nosti, boljim proizvodnim kvalitetom, i niòm cijenom promjenili su prirodu industrijske prakse. Me|utim,primjena ra~unara je dozvolila provo|enje naprednijih tehnika modeliranja. Ra~unari su {iroko kori{teni uinènjerskim aplikacijama, ali njihova primjena je ipak ograni~ena na jednostavnije algoritamske prora~une.U stvari, mnogi inènjerski problemi nisu prikladni da se jednostavno algoritamski rje{avaju. Jedna klju~na

konkurentska prednost za moderna proizvodna preduze}a je fleksibilnost u brzom reagovanju na trì{nepritiske i potrebe kupca. Primarno ograni~enje nije trud ili kapital, nego informacija. Tradicionalna pri-

mjena ra~unara u proizvodnim rje{enjima je da pomaù upravljati informacijama pridruènih pojedina~nimzadacima preko CAD-a, toka procesa, procesa kontrole i dijagnoze. Na nesre}u takvi sistemi nisu dobrointegrisani i ~ine malo olak{anje pri podjeli informacija i kordinaciju pri odlu~ivanju. Kao odgovor istraìva~ipoku{avaju razviti integrativne radne okvire koji u~inkovito povezuju zajedno konstruktore, softverske si-steme, ma{ine i aktivnosti preko jednog velikog, geografski raspr{ene proizvodne kompanije. Do sada,

istra ivanje je bilo fokusirano na softverske alate (softverski programi raspore|eni preko cjelokupne mre era~unara), me|utim organizaciona struktura alata ~ini se da je zna~ajnija od toga.

Klju~ne rije~i: Proces konstruisanja, CAD, PDM

A DESCRIPTION OF A DESIGN ENVIRONMENTNedàdRep~i},Ph.D.,BSc.Mech.Eng.,FacultyofMechanicalEngineering,Univer-sityofSarajevo,71000Sarajevo,Vilsonovo{etali{te9,SUMMARY

This paper is a description of a design environment, which attempts to address the problem of toolintegration in the design process. The growing complexity of manufacturing processes and the needfor higher efficiency, greater flexibility, better product quality, and lower cost have changed the natureof industrial practice. Meanwhile, the application of computers has allowed the implementation of more

advanced modeling techniques. Computers have been widely used in engineering applications, buttheir use has been limited almost exclusively to purely algorithmic solutions. In fact, many engi-neering problems are not amenable to purely algorithmic computation. A key competitive advantagefor modern manufacturing enterprises is the flexibility to react swiftly to market pressures and cus-tomer needs. The primary limitation is not labor or capital, but information. Traditional applicationsof computers in manufacturing provide point solutions that help manage information associated with

individual tasks such as CAD, scheduling, process control and diagnosis.Unfortunately, such systemsare not well integrated and do little to facilitate the sharing of information and coordination of deci-sions. In response, researchers are attempting to develop integration frameworks that seamlessly tietogether people, software systems, machines, and activities across a large, geographically dispersed,

manufacturing enterprise.Until now, research in the field has been focused on the software tools( soft-ware programs distributed over the whole network of computers); however, the organizational struc-tures of the tools seem to be significant as well.

Key words: Design process, CAD, PDM

PREGLEDNIRAD

SUBJECTREVIEW


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1.UVODPostoji danas jedan ponovljeni interes u konstruisa-

nju kao jedan dio inènjerske edukacije i kao jedanaspekt inènjerstva. Ovo je registrovano u dva prav-

ca, sa poku{ajima pove}ati sadràj inènjerskogmodeliranja inènjerskih tokova i povezuju}i inènjer-stvo sa industrijskim dizajnom. Sve vi{e prakti~nadizajn aktivnost je komplementirana pomo}u lekcija

koje obuhvataju tehnike modernih dizajn analiza. Oneuklju~uju konstruiranje obzirom na zamor, FE analize,

modeliranje obzirom na pouzdanost, dizajn premakvaliteti, optimizacija modeliranja i modeliranje zamontaù i proizvodnju. Mada je glavna namjera ovograda izvje{taj o pristupu preuzimanja inènjerskogmodeliranja, ipak je prvo potrebno dati pregledglavnih elemenata CIM-a. Postoji jedan pristup CIM-

u koji se ~ini konzistentnijim tj. umjesto jednostavnogzamjenjivanja sa akronimom CAD/CAM ( Dizajniranjepodràno ra~unarima / Proizvodnja podràna ra~unari-ma ) sa jednim modernijim CAD/CAM-om CIM-a, pri~emu se dodaju pojmovi koji uve}avaju integrativne

aplikacije. êsto, ova perspektiva je pra}ena pret-postavkom da automatizacija kreiranja i rasporednumeri~ke kontrole podataka postavljenih za obraduna alatnim ma{inama je osnovni cilj CIM-a. To nijeza sugerirati da efektivne CAD/CAM aplikacije usmje-rene prema NC generisanju nisu nu`ne. Umjesto ovih

pokazatelja potreba za jednim mnogo {irim pogledomprema CIM-u, koji moè uklju~iti ove aplikacije, alikoji obuhvata i druge funkcije proizvodnih preduze}asu dobro do{le.. Drugi pogled CIM-a prepoznaje daizdanci automatizacije su kreirana u mnogim pre-duze}ima i da oni mogu biti kategorizirani u ~etiri

grupe. Ove grupe su izlistane ispod sa tipi~nimizdancima automatizacije na|enih u ovim grupama.

CAD/CAMGrupna tehnologija, Inènjering podràn

ra~unarima (CAE),Konstruisanje podràno ra~unarima ( CAD ),Proizvodnja podràna ra~unarima ( CAM ).

PlaniranjeproizvodnjeikontrolaKontrola zaliha, Optere~enost prodajnih objekata,Planiranje kapaciteta, Prvenstvo u redoslijedu,Prodaja.

Automatizacijapreduze}aProizvodnja podràna ra~unarima, Robotika,NC/DNC/CNC, Fleksibilni proizvodni sistemi,Sistemi automatskog rukovanja materijalima,

Automatizirana test oprema, Kontroleri procesa. Op{teposlovnoupravljanje

Op}enito i formiranje cijene, Marketing,Ulaz poru|be,Pomo} pri odluci, Radni pregled, Platne liste.


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1.INTRODUCTIONThere is a renewed interest in design as a part ofengineering education and as an aspect of engi-

neering. This is noticeable in two ways, with attempts

to increase the engineering design content of engi-neering courses and by combining engineering withindustrial design. All the more practical design workis complemented by lectures covering moderndesign analysis techniques. These include design

against fatigue, FE analysis, design for reliability,design for quality, design optimisation and design for

assembly and manufacture. Although the main pur-pose of this paper is to report the approach takento engineering design, it is first necessary to give

an overview of the main elements of the CIM.There is a view of CIM which seems to consist of

simply replacing the acronym CAD/CAM (ComputerAided Design/Computer Aided Manufacturing) withmore fashionable one of CIM and adding the notionof increased application integration. Often, this per-

spective is accompanied by the assumption thatautomating the creation and distribution of numeri-cal control data sets for operating machine tools isthe fundamental goal of CIM. This is not to suggestthat effective CAD/CAM applications directed towardNC generation are not necessary. Instead this indi-cates the need for a much broader view of CIM,

that may include these applications, but whichembraces the other functions within the manufactur-

ing enterprise as well.Another view of CIM recognizes that islands ofautomation have been created in many enterprisesand that these can be categorized into four groups.These groups are listed below along with typical

islands of automation found in these groups.

CAD/CAMGroup technology ,Computer-aided engineering

(CAE),Computer-aided design ( CAD ), Computer-aidedmanufacturing ( CAM ). Manufacturingplanningandcontrol

Inventory control ,Shop loading,Capacity planning,Master scheduling,Purchasing.

FactoryautomationComputer-aided manufacturing,Robotics,NC/DNC/CNC, Flexible manufacturing systems,Automated materials handling systems, Automat-

edtest equipment, Process controllers.

GeneralbusinessmanagementGeneral and cost accounting, Marketing,Order entry,Decision support, Labor collection, Payroll.


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2.ENGINEERINGDESIGNEngineering Design methodology explains the integrat-ed influence of theories, strategies, and design toolson the final results quality. Modern technology ischanging faster then education and the marketdemands for engineering designers are changing asfast as technology changes. Historically, the engi-

neering process developed through trial and errorapprenticeship, followed by a shift to scientific orient-ed engineering education. This paper deals with the

problem of applying knowledge engineering techniquesin the process of designing mechanisms. I want tostart with design, because it is a highly-creative area,and as such, one in which computers, because theyare capable only of routine tasks, would seem to be

able to play no part. In fact, computers are used wide-ly in design work, which leads people to think thatthey are a lot brighter than they really are. To seewhat role computers can play in design work, we first

have to examine the nature of the design processitself. Design is the application of technology and aes-thetics to the solution of a specific practical problem.In some areas, the technology dominates, while in oth-ers the aesthetic aspect is seen by many people as

primary, although the technological underpinning mostdefinitely remains. There are three distinct types of

operation in the design process, and they are:

The formulation of ideas for possiblesolutions to the problem,

The analysis of these ideas to see if theywill work,

The selection of one solution as the "best",on whatever criteria one wants to use.

The first step is the creative one: how creativedepends on the novelty and the difficulty of the prob-lem. It involves formulating some possible solutions tothe problem. There is no immediate requirement that

all these solutions be workable, or even sensible.Theessential element in this process is that of synthesis.What the designer is doing is bringing together:

Technical knowledge, in the form of basicprinciples, often from a wide range of fields,

Past experience, with similar projects andaesthetic sense.

They combine these into a mix which fits this par-

ticular situation, and so come up with one or moresolutions that might work. The strategies used to dothis are many and varied, and are learned by exam-

ple from other professionals, and by experience.They involve things like recasting a problem into dif-

2.IN@ENJERSKIDIZAJNMetodologija inènjerskog dizajna obja{njava inte-

grisani uticaj teorija, strategija, i alata modeliranja nakona~ne rezultate kvaliteta. Moderne tehnologije

mjenjaju se brè od edukacije i trì{nih zahtjeva, akostruktori-projektanti mjenjaju se isto tako brzo kaoi tehnolo{ke promjene. Istorijski, inènjerski procesrazvijen je kroz poku{aj i gre{ke zanatstva, slijede}ipomake ka nau~no orjentisanoj inènjerskoj edukaci-ji. Ovaj rad bavi se sa problemom primjene tehnikainènjerskog znanja u procesu dizajniranja ma{inskihkonstrukcija. Ako se eli startati sa dizajnom,a budu}ije ono visoko kreativno podru~je i kao takvo u kojemra~unari su sposobni samo za rutinske zadatke, ~inise da bi trebalo biti sposoban uraditi to bez njihovogu~e{}a. U stvari, ra~unari su upotrebljeni {iroko u po-

stupku modeliranja, koji vodi konstruktora ka misli dasu oni mnogo bistriji i efikasniji od onog {to sustvarno. Da bi stvarno vidjeli koju ulogu ra~unari moguigrati u procesu konstruisanja, mora se prethodno ispi-tati priroda samog procesa modeliranja. Modeliranje je

primjena tehnologije i estetike ka rje{avanju specifi~nihprakti~nih problema. U nekim podru~jima, tehnologijadominira, dok u drugim estetski aspekt je vi|en od

mnogih ljudi kao primaran, mada tehnolo{ka kompo-nenta je kona~no presudna. Postoje tri distinktivna tipaoperacija u procesu konstruisanja, i oni su:

Formulacija ideje za mogu}a rje{enja problema,Analize ovih ideja da se vidi kako }e one

funkcionisati, Izbor jednog rje{enja kao "najboljeg", ma kojikriterij se èli upotrebiti.

Prvi korak je kreativni korak: kako kreirati zavisnood novina i te{ko~a problema. On obuhvata for-

mulisanje nekih mogu}ih rje{enja problema. Nesmije biti zahtjeva koja ova rje{enja ne bi mogla

uraditi ili ~ak osjetiti. Bitan elemenat u ovom pro-cesu je ova sinteza. Kakav konstruktor je zavisiod dva elementa:

Tehni~kog znanja, u formi osnovnih principa,~esto iz jednog {ireg podru~ja nau~ne oblasti,

Prethodno iskustvo, sa sli~nim projektima iestetskim osje}ajem.

Oni kombinuju ovo u jednu mje{avinu kojapode{ava ovu pojedina~nu situaciju, i tako se dolazido jednog ili vi{e rje{enja koja bi mogla raditi.

Strategije upotrebljene da ovo u~ine su mnoge irazli~ite, a izu~avaju se pomo}u primjera od drugihprofesionalaca, i pomo}u iskustva. Oni obuhvatajustvari poput rikastinga jednog problema i razli~itimoblicima done{enih na osnovu sli~nosti sa pozna-


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tim problemima, razbijanjem problema u manje, pri-lagodljivije komade, dudling, i mnoge druge. Pos-toji jedan broj pojava o ovom {to ~ini da proces

konstruisanja je vrlo te{ko emulirati na ra~unaru:

înjenica je da nema dizajna koji slijedi ta~noneke procese, budu}i su razli~iti zahtjevi, Varijabilnost izvora koji bi mogli biti prisni za

op{te principe, i ~injenica da preciznaprimjena ovih moè da razlikuje i estetskezahtjeve.

Sve ovo ~ini to da je nemogu}e ispisati kruti setpravila zahtjevanih od ra~unara prije nego se to nepredstavi. Me|utim, ovo nije zaustavilo upotrebura~unara u asistiranju pri ovom radu. Posti}i ovaj ciljkoji je zahtjevan, mora se planirati i konstrukcija

proizvodnih sistema, kao i kvalifikovani dizajn zadatakcentralne va`nosti koji mora biti izvr{en u vezi sa

modeliranjem proizvoda koji }e biti proizvedeni. Ovajdizajn rad zahtjeva uvje`ban, dobro edukovan i isku-

san proizvodni sistem dizajnera, opremljen sa efikas-nim alatkama. To je njihova odgovornost uvidjeti toda novi proizvodni sistemi ta~no traè funkcionalne

zahtjeve koji su definisani proizvodima koji treba dabudu izra|eni. Nadalje, to je njihov zadatak dauklju~e ljudske faktore u modeliranje i time uzmuu~e{}e i psiholo{ke i fiziolo{ke potrebe radnika i

proizvodnih planera. U dodavanju ovih elemenata zaovaj dizajn rad, mora sve ovo biti konkurentno

kratko.

2.1Primjenametodekona~nihelemenataJedna razlo`na primjena metode kona~nih elemena-ta zahtjeva pojednostavljenje procesa modeliranja,

respektivno spojiti to sa CAD procesom, FEM pred-procesorima razvijenih za ovu namjenu. Rje{enje

koje je obi~no prezentovano sadrì dva koraka. Uprvom koraku jedan takozvani osnovni model seupotrebljava, koji zapravo predstavlja prethodni ste-

pen modela kona~nog elementa. Osnovni modelmoè biti izveden prvenstveno iz oblika karakteristikemodela CAD sistema. On se transformi{e u stvarniFEM - model pomo}u jedne automatske generacije

mreè. Jedan model kona~nog elementa moè bitizami{ljen kao jedan sistem krutih opruga.Kad se primjeni jedno optere}enje na strukturi, svi ele-

menti deformi{u su dok se sile ne izbalansiraju. Zasvaki element u modelu, jedna~ine mogu biti pisane

u skladu pomjeranja i sila na ~vorovima. Element kojije uzet za primjer ovdje je jedan 2D kvadrat koji ima~etiri ~vora. Svaki ~vor ima dva stepena slobode koji

su pridruèni njima ( pomjeranje u X i Y pravcima),tako da element ima ukupno osam stepeni slobode.


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ferent forms to bring out similarities with known prob-lems, breaking the problem into smaller, more tractable

pieces, doodling, and many others. There are a num-ber of features about this which makes the designprocess very difficult to emulate on the computer:

The fact that no design follows exactly thesame processes, because of the differingrequirements,

The variety of sources which can be tappedfor general principles, and the fact that the

precise application of these may differ and theaesthetic requirement.

All of these make it impossible to write down the rigidset of rules required be a computer before it will per-form. However, this does not stop us using a com-

puter to assist us with the hackwork.To achieve thisgoal it is required that we regard planning and con-struction of manufacturing production systems as aqualified design task of central importance which must

be carried out in conjuction with the design of prod-ucts to be manufactured. This design work requires

skilled, well educated and experienced manufacturingsystem designers equipped with efficient tools. It istheir responsibility to see to it that the new manu-facturing production systems accurately meet the func-tional requirements as defined by the products to be

produced. Furthermore it is their task to includehuman factors in the design and thereby anticipatethe psychological and physiological needs of theworkers and production planners. In addition the leadtime for this design work must be competitively short.

2.1ApplicationoftheMethodofFiniteElementsA reasonable application of the Method of Finite Ele-ments demands to simplify the modelling process,

respectively to connect it with the CAD process, FEMpreprocessors have been developed to this aim. Thesolution presented consists of two steps. In the firststep a so called basic model is used, which is aprevious stage of the finite-element-model. The basicmodel can be derived advantageously from the formfeature model of a CAD-system. It is transformed tothe real FEM-model by means of an automatic mesh

generator. A finite-element model can be thought ofas a system of solid springs. When a load is appliedto the structure, all elements deform until all forces

balance. For each element in the model, equations

can be written relating displacements and forces atthe nodes. The element shown here, for example, is

a 2D quadrilateral having four nodes. Each node hastwo degrees of freedom associated with it (displace-

ments in X and Y directions), so that the element has


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Tamo mora tako|e biti jedna ~vorna sila za svaki~vorni stepen, tako postoji tako|e osam ~vornih sila

za elemenat. Ova pomjeranja i sile su identifikovanepomo}u jednog brojnog koordinatnog sistema za ulazkompjuterskog programa.

Kad je jedna struktura modelirana, pojedina~ne garni-ture matri~nih jedna~ina su automatski generisane zasvaki elemenat. Elementi u modelu dijele zajedni~ke~vorove tako pojedina~nih garnitura matri~nih jedna~ina

i mogu biti kombinovane u jedan globalni set matri~nihjedna~ina. Ovaj globalni set je u relaciji svih ~vornihstepeni slobode ka ~vornim silama, i ~vorni stepenislobode rije{eni su simultano iz globalne matrice. Kadasu poznata pomjeranja za sve ~vorove, onda je tako|erpoznato stanje deformacije svakog elementa. A kadaje poznata deformacija svakog elementa onda su po-znati i naponi i pomjeranja svakog elementa. Za obi~ne

stati~ke analize metod kona~nog elementa je dvoste-peni proces. ^vorna pomjeranja su prvo istovremenoizra~unata iz elementa krutosti i ~vornih sila, iunutra{njih i vanjskih. Slijede}e, izra~unavaju se naponi,op}enito kod svakog element-centroida.Budu}i su pomjeranja izra~unata samo za kona~an

broj ta~aka u strukturi, metoda kona~nih elemenataje ipak jedna numeri~ka aproksimacija prili~no uda-ljena od ta~nog rje{enja. Parametarske karakteristike

postaju sve vi{e zajedni~ke u FEA paketima. Klju~napovoljnost parametarskih karakteristika je da one

dopu{taju korisnicima da vide efekte dizajn promje-na veoma brzo. Sa adekvatnim planiranjem. Korisni-ci mogu definisati jedan FE model cjelokupno u

izrazima varijabli ili parametara. âk mre`ne karak-teristike mogu biti definisane kao parametri.

2.2Uop{teno-svrhakretanja-analizasoftverapokrenutihnaPC-uPrikaz je dat sa namjerom da ukaè da postoje i diza-

jneri koji èle isprobati nekoliko ideja na brz na~in.

Drugi paketi, modelirani za zahtjevnije zadatke, suraspolo ivi na UNIX radnim stanicama. One mogu nesamo analizirati optere}enje na zglobovima i pinovima,nego tako|er optimiziraju konstrukcije pomo}uodre|ivanja najbolje duìne za moment krakova, i takodalje. Paketi dizajnirani za upotrebu na PC-u tipi~no

su mehani~ki dinami~ki simulatori. Korisnik defini{eobjekte sa specificiranim masama, tada posmatra to

kao program koji pokazuje {ta se doga|a pod datimsetom uslova. Geometrije mogu biti ili u samom pro-gramu ili importovane preko dxf fajlova. Modeli imajufii~ka svojstva koja uklju~uju masu, stati~ko i kineti~ko

trenje, elasticitet,moment inercije, i elektrostati~ki naboj.Raspoloìva ograni~enja u PC baziranim programimauklju~uju zglobove, prigu{iva~e, uàd, neelasti}ne

poluge, opruge, ispravlja~e, i motore spojenih masa.Korisnici ograni~avaju mase sa pinovima, prorezima,


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a total of eight degrees of freedom. There must alsobe a nodal force for each nodal degree, so there arealso eight nodal forces for the element. These dis-placements and forces are identified by a coordinatenumbering system for entry the computer program.

When a structure is modeled, individual sets ofmatrix equations are automatically generated for eachelement. The elements in the model share common

nodes so individual sets of matrix equations can becombined into a global set of matrix equations. This

global set relates all the nodal degrees of freedomto the nodal forces, and the nodal degrees of free-dom are solved simultaneously from the global

matrix. When displacements for all nodes are known,the state of deformation of each element is known.

And, when deformation of each element is know, thestress and strain within the element are also known.

For simple static analysis, the finite-element methodis a two-step process. Nodal displacements arefirst simultaneously calculated from the element

stiffness and the nodal forces, both internal andexternal. Next, stresses are calculated, generally atthe each element's centroid. Because displace-

ments are calculated for only a finite number ofpoints in the structure, the finite-element method isa numerical approximation rather than an exactsolution.Parametric features are becoming more common in

FEA packages. The key benefit of parametric fea-tures is that they let users see the effects of designchanges quickly. With adequate planning, users candefine an FE model entirely in terms of variables or

parameters. Even mesh characteristics can bedefined as parameters.

2.2General-purposemotion-analysispackagesrunonPCs.They are aimed at designers who want to try out

a few ideas quickly. Other packages, designed formore demanding tasks, are available on Unix work-stations. These might not only analyze loads onpivots and pins, but also optimize designs bydetermining the best length for moment arms, and

so forth. Packages designed for use on PCs typi-cally are mechanical dynamics simulators.The userdefines objects with specified masses, then watch-es as the program shows what happens under

given sets of conditions. Geometries can either bedevised in the program itself or imported via .dxf

files. Models have physical properties that includemass, static and kinetic friction, elasticity, momentof inertia, and electrostatic charge. Available con-

straints in PC-based programs include pulleys,joints, dampers, ropes,inflexible rods, springs, actu-


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ators, and motors to join masses. Users constrainmasses with pin, slot, keyed slot, and rigid joints,and specify forces acting on the model. Motionsimulators calculate equations of motion throughnumerical integration. Users define the time steps

in the simulation to determine accuracy. Large timesteps are acceptable for slowly moving objects, butmay throw off accuracy. These simulators provideseveral different numerical methods that trade offaccuracy versus speed of calculation. PC-basedmotion simulators work strictly with 2D rigid bod-ies at this point. For situations where deflectionsplay a part in the simulation, and where mecha-nisms move in 3D, workstation simulators arerequired.SolidWorks is the leader of a new class of low-

priced, feature-based solid modeling programs for

Windows that is challenging the dominance ofPro/Engineer. Yet learning to use this new software

isn't as easy as it looks. Designing Parts with Solid-Works helps new users of SolidWorks mastering fea-ture-based modeling using innovative approaches.Some of the unique benefits of this book include:

Maximum use of graphic examples withminimal reading.

A project-oriented approach that has userscreating part models while learning.

The most efficient ways to designing parts ineach situation.

Techniques for capturing design intent, enablingworkers to reuse models reliably.

Tips and tricks designers need to know to gettheir work done with time to spare.

The essential guide for CAD managers on the wayup. It will help you get more out of your CAD sys-tems after you've bought them. You'll learn how to

plan productivity increases, set goals and measure

your progress, and overcome fears of subordinates,superiors, and project managers who distrust CAD. Itshows you how to simplify administrative tasks,upgrade training programs,improve communicationswith other departments, and apply CAD technology totasks that yield the highest return. Searching for CAD

software that fits your needs? It gives you featurelists, functional capabilities, and computing require-

ments for CAD and CAM programs. Disciplinesinclude mechanical design and drafting, architecturaldesign, mapping, three-dimensional modeling, struc-tural analysis, NC tooling, and animation.

zatvorenim prorezima, i krutim zglobovima, i specifici-ranim silama koje djeluju na modelu. Kretanje simu-latora ra~una jedna~ine kretanja kroz numeri~ku inte-

graciju. Korisnici defini{u vrijeme koraka u simulacijida odrede ta~nost. Velika vremena koraka su prih-

vatljiva za sporija kretanja objekata, ali mogu znatnosmanjiti ta~nost. Ovi simulatori snabdjeveni su sanekoliko razli~itih numeri~kih metoda koji se dis-tribuiraju prema ta~nosti verzije brzine ra~unanja. PC-

bazirani simulatori kretanja rade strogo sa 2D krutimtijelima kod neke ta~ke. Za situacije gdje ugibi igra-

ju neku ulogu u simulaciji, i gdje mehanizmi se kre}uu 3D radnim stanicama simulatori su zahtjevniji.SolidWorks je predvodnik jedne nove klase relativno

niske cijene, feature-based solid programa za mode-liranje za Windows, koji je posljedica izazova domi-

nacije Pro/Engineer-a. Tek izu~avanje upotrebe ovog

novog softvera nije uop{te lagano kako to izgleda.Modeliranje dijelova sa SolidWorks-om pomaè novim

korisnicima SolidWorks-a mastering feature-basedmodeliranje koriste~i inovativne pristupe. Neke odunikatnih povoljnosti ovog softvera odnose se na:

Maksimalnu upotrebu grafi~kih primjera saminimalnim ~itanjem,

Jedan projektno-orjentisani pristup kojikorisnicima kreira dijelove modela dok ~itaju,

Najefikasniji na~ini dizajniranja dijelova u svakoj

situaciji, Tehnike za prihvatanje dizajn namjera, osposob-

ljavaju}i radnike da pouzdano ponovoupotrebljavaju modele,

Tips and tricks dizajneri treba da znaju dadobijaju i to, {to njihov rad ~ini efikasnijim.

Nuàn je vodi~ za CAD menadère na ovom putu.To }e pomo}i da se dobiju informacije za CAD sis-teme, nakon njihove instalacije i konfiguracije. Tu se

izu~ava kako planirati uve~anje produktivnosti, posta-

vljanje ciljeva, i mjerenje napretka, i prevazilaènjestrahova subordinatora, superiora, i projekt-menadèrakoji nevjeruju CAD-u. Ujedno ovo pokazuje kakopojednostaviti administrativne zadatke, prilagoditi pro-grame za obuku, pobolj{ati komunikaciju sa drugimodjeljenjima, i primjeniti CAD tehnologiju ka zadacima

koji su najkorisniji. Uvijek treba traìti softvere samoza pode{avanje vlastitih potreba. Ovo daje karakter-isti~nu listu funkcionalnih sposobnosti, kao i kom-pjuterskih zahtjeva za CAD i CAM programima. Dis-cipline uklju~uju ma{insko konstruiranje i crte`,

arhitektonsko crtanje, mapiranje, trodimenzionalno

modeliranje, strukturalne analize, NC alate, i animaci-je.


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2.3KorisnikiposluìlacprirodaProgresi u {tampa~ima, radnim stanicama i mediji-

ma za arhiviranje i odlaganje podataka pomaùinènjerima da budu produktivniji. Hijerarhija upotre-

bljena u CAD/CAM mreàma danas tipi~no je hijer-arhija jedne korisnik/posluìlac prirode. Svaka radnastanica, ima njenu vlastitu centralnu procesorjedinicu ( CPU ) i lokalni disk za odlaganje podata-ka. Mre`ni rad moè tako|e imati jedan fajl serverkoji sadràva CPU i tvrdi disk za odlaganje podata-ka, kao i magnetske trake za arhiviranje.Jedan klju~ni element client/server sistema je ovajfile-server softver snabdjeven fajlom rezimea ka

korisniku. Korisnik radnih stanica ne mora znati gdjefajlovi su fizi~ki smje{teni. Ovo pona{anje je

povoljno i {to se zove jedan zami{ljeni fajl sistem,

koji dopu{ta slanje fajl sistem zahtjeva ka jednojlokalnoj radnoj stanici fajl sistema ili ka udaljenom

serveru putem mreè. Inènjerske radne staniceodnedavno imaju i multimedijalne sposobnosti. Sili-con Graphics Inc. je ve} duì period predvodnik u

grafi~kom procesiranju. SGI Indy serija radnih stani-ca, bazirana na jednom 64-bit Risc procesoru, imaunutra{nji audio capture i opcionalnu kameru zavideo telekonferenciju. Druge karakteristike uklju~ujudisplej rezoluciju ka 1.280x1.034, glavnu memoriju

kapaciteta ka 256MB, i povoljnost dodavanja plo~a

koje ubrzavaju grafi~ku manipulaciju 3D modela.Sli~no, Sun SPARCstation radne stanice imajudovoljno procesor snage da upravljaju video telekon-ferencijama i dekompresiranje MPEG video bezupotrebe unutra{njeg dodavanja plo~a.20-HS11upotrebljava jedan hiper SPARC procesor pokrenut

kod 266 MHz i moè upravljati i sa 64MB glavnememorije.Unutra{nje dodavanje kartica ubrzava kliping i rotaci-

ju 3D slika. Neke napredne mreè startaju evolvi-ranjem drugog sloja hijerarhije iznad koje je fajl

server. Ideja je spojiti fajl server preko jednog{irokog podru~ja mre`nog rada ka masivnom arhivi-ranju olak{ane sadràvanjem opti~kih diskova juke-boxes, i magnetnih traka ili biblioteke opti~kih disko-va. Ovaj dodatni sloj je osnovno jedan near-line sis-tem arhiviranja koji drì informaciju raspoloìvu sa

pristupnim vremenom reda sekunda ili duè. Zaprimjer, mogu}e je slanje samo 2D crteà jednogdijela da bude u servisnom birou kreiran kao solid

model, a na osnovu printa. Za relativno jednostavnedijelove, ovo }e vjerovatno uzeti vremena isto kaoda se kreira solid model sa jednim CAD programom.

Ali situacija se dramati~no mjenja kada dijelovipostaju vi{e i vi{e kompleksni. Neki CAD programiba{ zbog ovoga rade brè jedan od drugog.Feature-based ili modeleri varijacione geometrije kao

{to je Pro/Engineer mogu obi~no generisati modele


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2.3Client/servernatureAdvances in printers, workstations, and storagemedia help make engineers more productive. Thehierarchy used in CAD/CAM networks today typically

is one of a client/server nature. Each workstation,orclient, has its own central processing unit (CPU) andlocal disk storage. The network may also have a file

server that contains CPU and hard disk storage, aswell as magnetic tape storage. A key trait ofclient/server systems is that the file-server software

provides file abstraction to the client. The worksta-tion user doesn't need to know where the files phys-

ically reside. This behavior is courtesy of what iscalled a virtual-file system which allows sending file

system requests to a local workstation file system orto a remote server across the network.

Engineering workstations have in recent years sport-ed multimedia capabilities. Silicon Graphics Inc. haslong been considered the leader in graphics pro-cessing. The SGI Indy series workstation, based on

a 64-bit Risc processor, has internal audio captureand optional camera for video teleconferencing. Otherfeatures include display resolution to 1,280 1,034,

main memory capacity to 256M bytes, and the avail-ability of add-in boards that accelerate graphic manip-ulations of 3D models. Similarly, Sun SPARCstationworkstations have sufficient processing power to han-

dle video teleconferencing and decompressing MPEGvideo without the use of add-in boards.The 20-HS11 uses a hyperSPARC processor running

at 64 MHz and can handle up to 64M bytes of mainmemory. Add-in cards accelerate the clipping androtation of 3D images. Some advanced networks arestarting to evolve another layer of hierarchy abovethat of the file server. The idea is to connect thefile server over a wide area network to massive stor-

age facilities consisting of optical-disk jukeboxes,and mag tape or optical-disk libraries. This addi-

tional layer is basically a near-line storage systemthat keeps information available with access timeson the order of seconds or longer. For example,

sending only 2D drawings of a part to be fabricat-ed forces the service bureau to create the solid

model from the prints. For relatively simple parts, itwill probably take about as long to create a solid

model with one CAD program as it would withanother. But the situation changes dramatically asparts become more and more complex. Some CADprograms are just faster to work with than others.Feature-based or variational geometry modelers such

as Pro/Engineer can usually generate models muchmore quickly than modelers based on Boolean oper-ators. The difference in modeling time becomes morepronounced in complicated models that incorporatefeatures such as sculpted surfaces, numerous bends


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mnogo brè od modelera baziranih na Bulovimoperacijama. Razlika u vremenu modeliranja postajevi{e izraèna u komplikovanijim modelima koji inkor-

poriraju karakteristike takve kao skulptorske povr{ine,brojne prelome, savijanja,radijuse itd.Izraz virtualna

realnost dolazi iz zna~enja sposobnosti " {etatiokolo" 3D matemati~kog modela i pogleda na njihkao da oni fizi~ki egzistiraju u prostoru.Neki CAD modeli sada mogu biti pogledani u virtu-

alnoj stvarnosti kroz upotrebu specijalnih pogleda{ljemova ili ~a{a, i softvera koji formate video slikakreira utiskom dubine. Utisak dubine rezultira izvi|enja dva perspektivna pogleda vi|enih pomo}u

na{eg lijvog i desnog oka.Imaju dva generalnana~ina kreiranja ovih pogleda. Pristup upliva u virtu-alnu stvarnost {ljemova je da treba upotrebiti dvamala ekrana, jedan za svako oko, i poslati svaki

pogled respektivnom ekranu. Jedan drugi metod,kojije vi{e tipi~an upotrebljava se u CAD aplikacijama,multipleks dvije slike na sekvencijalnim video poljimajednog obi~nog monitora. Posmatra~ koristi jeftinijiset ~a{a koje sadr avaju jedan infrerirani prijemnik ipolarizirane lijeve i desne le}e.Jedan infreriranioda{ilja~ sinhronizovan ka promjenljivom video polji-

ma {alje signale ka oku koji uzrokuje svaka le}a za-tvaranjem i otvaranjem odgovaraju}e vrijeme, tako da

svako oko vidi korespondiraju}i lijevi ili desni pogled.Konstruisati trodimenzionalne displeje iz jednog mod-

ela u jednu CAD bazu podataka, softveru mora prvobiti data jedna ta~ka pogleda posmatra~a. Sa infor-macijom o ta~ki pogleda, kompjuter moè ra~unatikoje povr{ine CAD modela trebaju biti vidljive iz ovepojedina~ne perspektive. Tipi~an pristup sortiranjuvidljivih povr{ina starta sa onim najzatvorenijim ka

posmatra~u i radi obrnuto. Najzatvoreniji objektiblokiraju pogled nekih objekata udaljenijih, i takonadalje. Postoje tako|er dvije kliping operacijepridruène sa pogledom na ekranu. Prva operacijaupotrebljava rastojanje izme|u posmatra~a i modela,

ra~unaju}i koji dio modela treba biti vidljiv naekranu. Jo{ mnogo toga izvan posmatranog okviraje ignorirano. Druga operacija odlu~uje koji predmetine bi trebali biti vidljivi, budu}i oni su kompletnoskriveni putem objekata bliìh posmatra~u.Jedanputkada kompjuter prora~una koje povr{ine su vidljive,on odre|uje boju svake vidljive povr{ine, koje zavise

i od osvjetljenja i od originalne boje povr{ine.Napredni CAD programi mogu ~esto dodijeliti jednu

raznolikost simuliranih svjetlosnih izvora takva kaospot svjetla, obojena svjetla, usmjereni svjetlosniizvori kao poput svjetla koja dolaze kroz jedan pro-

zor, i tome sli~no.Jednom CAD program odre|ujeosnovnu koloraciju, i on prora~unava sjenu za svaki

piksel na displeju. Napredni programi optimizirajurealnost i mogu uposliti sofistificirane metode zagenerisanje ove vrste {ejdinga. Prora~uni involvirani,


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and radii, and so forth. The term virtual reality hascome to mean the ability to "walk around" 3D math-ematical models and view them as though they phys-

ically existed in space. Some CAD models now canbe viewed in virtual reality through use of special

viewing helmets or glasses, and software that formatsvideo images to create the impression of depth.The impression of depth results from seeing two per-

spective views of a three-dimensional object that cor-respond to the same views seen by our left and righteyes. There are two general ways to create theseviews. The approach employed in virtual reality hel-

mets is to use two small video screens, one for eacheye, and send each view to the respective screen. A

second method, which is more typically used in CADapplications, multiplexes the two images onto thesequential video fields of an ordinary monitor. The

viewer wears an inexpensive set of glasses that con-tain an infrared receiver and polarized left and rightlenses. An infrared transmitter synchronized to the

alternating video fields sends signals to the eyewearwhich cause each lens to shutter on and off at the

appropriate time so that each eye sees the corre-sponding left or right view. To construct three dimen-sional displays from a model in a CAD database, soft-ware must first be given a viewpoint of the observer.With information about the viewpoint, the computercan calculate which surfaces of the CAD model would

be visible from that particular perspective.The typical approach to sorting visible surfaces

starts with those closest to the viewer and worksback. The closest objects block the view of someobjects farther away, and so forth. There are alsotwo clipping operations associated with the view onthe screen. The first operation uses the distance

between the viewer and the model to calculatewhich part of the model would be visible on the

screen.Everything else outside the viewing box isignored. The second operation decides which

objects would not be visible because they are com-pletely hidden by objects closer to the viewer.Once the computer has calculated which surfaces

are visible, it determines the color of each visiblesurface, which depends both on lighting and on theoriginal surface color. Advanced CAD programs canoften assign a variety of simulated light sources

such as spot lights, colored lights, directional lightsources as like light coming through a window, andso forth. Once the CAD program has determinedbasic coloration, it calculates a specific shade foreach pixel in the display.

Advanced programs optimized for realism mayemploy sophisticated methods for generating this sortof shading. The calculations involved, however, arelengthy and work best on high-end graphic work-

stations. High-end software may also add refine-


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me|utim su duì i rade najbolje na krajnje visokografi~kim radnim stanicama. High-end softver moètako|e dodati rafinate takve kao antialiasing smanjiti

jaggedness dijagonalnih linija, transparentnost ve}produciranih efekata, takvi kao magla ili zamazana

~a{a, i tekstura mapinga umjesto ra~unanja kolor vri-jednosti. Ovo daje izgled povr{ina kao {are drveta.

3.UPRAVLJANJEPODACIMAPROIZVODAU mnogim firmama, porast obima dizajna baziranog na

ra~unarima i analize podataka prijete preoptere~enjusistema za upravljanje ovim podacima. Upravljanjepodacima proizvoda ( PDM ) softver je dizajniran takoda osigura one inènjere koji su upotrebljavali praveverzije dizajniranja proizvoda podacima, spre~avaju}i

neautorizovane osobe od pregledavanja ili promjenepodataka, i osiguravanja onih promjena koje su slo-bodne samo poslije odgovaraju}eg pregleda i dozv-ole. Najsofistificiraniji sistemi mogu trasirati koje verzi-

je podataka su upotrebljene u izradi mnogih proizvo-da. Ne kao specifi~ni CAD ili CAE softver, PDM sis-temi dodiruju organizaciju cjelokupnog dizajn procesa.Vi ne moète kupiti jedno PDM mjesto da vidite kakoto dobro radi budu}i jedan sistem koji upravlja malim

iznosima podataka moè biti prekinut pod punimoptere~enjem va{e kompanije podacima modeliranja i

procedurama. Pronalaza~, da li brzo prototipisanje jekompatibilno sa va{om teku~om praksom i {ta va{afirma mora u~initi da bi to uspje{no upotrebljavala.U~iti o novim aplikacijama i produktivnosti-gradnjatehnika iz posebnih razgovora sa korisnicima eksper-tima. Za primjer, prona}i kako kreirati brzo pokretni i

proizvodni alat koriste}i brzo prototipisanje i kakopobolj{ati ta~nost i izlaz postoje}ih sistema. Vi }etetako|e izu~iti koliko to ko{ta i vrijeme osiguranja koje

moète o~ekivati od ovih novih metoda. Feature-basedmodeliranje usmjereno je ka konstrukciji geometrija

kao jednoj kombinaciji karakteristi~nih oblika.Konstruktor specificira karakteristike u inènjerskimizrazima takve kao otvore, proreze ili {upljine radijenego kao geometrijske izraze takve kao krugovi ilikutije. Features-i mogu tako|e pohraniti negrafi~keinformacije isto tako dobro kao i geafi~ke. Ova infor-macija moè biti upotrebljena u aktivnostima takvekao {to su drafting, NC, analiza kona~nih elemena-ta i kinematska analiza. Nadalje, feature-based paketi~esto snimaju geometrijsku konstrukciju i modifikaci-

ju sekvenci upotrebljenih i gradnji modela. Nekeverzije softvera za solid modeliranje koriste primitive

ili grani~nu reprezentaciju kao gradnja blokova zamodelirane dijelove. Sa primitivima, elementarni obli-ci su kombinovani u jednoj gradnji-blok modernih

kreiranih novih oblika.Bulove logi~ke komande, takve kao unija,razlika i


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ments such as antialiasing to reduce the jaggednessof diagonal lines,transparency for producing effects

such as fog or tinted glass, and texture mappinginstead of calculating a color value. This providesthe appearance of surfaces such as wood grains.

3.PRODUCTDATAMANAGEMENTIn many firms, the growing volume of computer-

based design and analysis data threatens to over-whelm systems for managing that data. Productdata management (PDM) software is designed to

assure that engineers are using the right version ofproduct design data, prevent unauthorized peoplefrom viewing or changing data, and assure that

changes are released only after appropriate reviewand approval. The most sophisticated systems cantrack which versions of data are used to manufac-ture each lot of products. Unlike specific CAD orCAE software, PDM systems affect an organization'sentire design process. You can't buy one PDM seatto see how well it works because a system that

manages small amounts of data might break underthe full load of your company's design data and

procedures.Discover whether rapid prototyping is compatible

with your current practices and what your firm mustdo to use it successfully. Learn about new applica-tions and productivity-building techniques from exclu-

sive interviews with expert users. For example, findout how to create short-run and production toolingusing rapid prototyping and how to improve accu-

racy and output of existing systems. You'll also learnwhat cost and time savings you can expect fromthese new methods.Feature-based modeling refers to the construction of

geometries as a combination of form features. Thedesigner specifies features in engineering terms

such as holes, slots, or bosses rather than geo-metric terms such as circles or boxes. Features canalso store nongraphic information as well. This infor-mation can be used in activities such as drafting,NC, finite-element analysis, and kinematic analysis.Furthermore, feature-based packages frequently

record the geometric construction and modificationsequences used in building the model. Some ver-sions of solid-modeling software use primitives orboundary representations as the building blocks formodeled parts. With primitives, elementary shapes

are combined in a building-block fashion to createa new shape.Boolean logic commands, such as union, difference,

and intersection, aid in forming new shapes. Withboundary definitions, 2D surfaces are swept through


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presjek pomaù u formiranju novih oblika. Sagrani~nim definicijama, 2D povr{ine su provu~enekroz prostor trasiraju}i volumene. Mnogi sistemi nudenekoliko tipova svipova pomaù}i kreiranju jedneraznolikosti oblika. Parametarski metodi zavise od

sekvenci operacija upotrebljenih u konstruisanjunekog ma{inskog dijela. Softver odràva jedan istori-jat promjena u specificiranim parametrima. Ta~ka spa-janja ove istorije drì trag operacija koje zavise jednaod drugih, tako da kad god se traì promjena jedne

specifi~ne dimenzije, sistem moè prilagoditi sveoperacije referentne prema ovoj dimenziji.

Za primjer, jedan krug predstavljaju}i jedan otvor zaklin moè biti konstruisan tako da je to koncentri~noka kru`nom prorezu. Ako prorez se kre}e tako ~inii krug za klin. Parametri su obi~no pokazani i izraz-ima dimenzija ili natpisa i sluè kao mehanizmi

pomo}u kojih se mjenja geometrija. Konstruktormoè promjeniti parametre ru~no mjenjaju}i jednudimenziju, ili pomo}u referencije njih ka jednoj var-

ijabli u jedna~ini koja je rje{ena ili pomo}u samogmodeling programa ili pomo}u vanjskih programatakvih kao {to su spreadsheets.Parametarsko modeliranje je najefikasnije u radu sadizajnima gdje promjene su vjerovatne ka sadràjudimenzionalnih promjena, radije nego velikim razlika-

ma geometrija. Ovaj ~lanak predstavlja jedan kon-cept i strukturu sistema za modeliranje. U skladu sa

dizajn iskustvom u inènjerstvu, sistem osposobljavaskicu dizajna i analizu napona formiraju}i jednu bazuza detaljisanje. Jedan komplet softver program jerazvijen za upotrebu sa CNC PUNCH/LASER PLAS-MA ma{inama. Sistem potpomaè cjelokupni ciklusCNC operacije i uklju~uje drafting, spre~ava

gu`vanje materijala, automatsko/ interaktivno gener-isanje G-koda, grafi~ku simulaciju CNC programa,gnje`|enje, downloading i uploading. Softver potpo-maè jedno {iroko podru~je ma{ina uklju~uju}iAMADA, TRUMPF, WHITNEY, BISTRONIC itd.

U dodatku, Nesting softverski paket snabdjeven jejednim kompletnim rje{enjem za interaktivno iautomatsko gnje`|enje razli~itih `lijebova. Windows-osnovna aplikacija je kompatibilna sa jednim {irokim

podru~jem CAD/CAM sistema ( DFX,IGES,CADL).Pomak promjena u inènjerstvu i nau~nim ra~unari-

ma, CAD/CAM i CAE sistemima i brzo prototipisan-je predstavljaju jednu dilemu. Da li uglavnom koris-titi alate koji ve} su na raspolaganju, ili se upustitiu domen novih tehnologija koje su revolucionarne

na trì{tu koje je izrazito konkurentsko. Izvje{taji naproizvodne pogre{ke omogu}uju da se izbjegnu sis-

temi sa gre{kama u ~ipovima i mati~nim plo~ama.Tehni~ki prora~uni zavise od poslovnih aplikacija.Inènjeri, nau~nici, ekonomisti i ostalo tehni~koosoblje daju brojne intenzivne zadatke. Konstruktori

proizvoda, postrojenja, gra|evina i infrastrukture traè


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space to trace out volumes. Most systems offer sev-eral types of sweeps to help create a variety of

shapes. Parametric methods depend on thesequence of operations used to construct thedesign. The software maintains a history of changes

in specific parameters. The point of capturing thishistory is to keep track of operations that dependon each other, so that, whenever it is told tochange a specific dimension, the system can update

all operations referenced to that dimension. Forexample, a circle representing a bolt hole may beconstructed so it is always concentric to a circular

slot. If the slot moves, so does the bolt circle. Para-meters are usually displayed in terms of dimensionsor labels and serve as the mechanism by which

geometry changes.The designer can change para-meters manually by changing a dimension, or by ref-

erencing them to a variable in an equation that issolved either by the modeling program itself or byexternal programs such as spreadsheets. Parametric

modeling is most efficient in working with designswhere changes are likely to consist of dimensionalchanges rather than grossly different geometries.This paper presents a concept and the structure ofthe system for the design. According to designexpirience in engineering, system enables layoutdesign and stress analysis forming a base for detail-

ing.A complete software program has been devel-

oped for use with CNC PUNCH/LASER PLASMAmachines.The system supports the entire cycle of CNC oper-

ation and includes draft ing, unfolding,automatic/interactive G-code generation, the graphicsimulation of CNC programs, nesting, downloadingand uploading.The software supports a wide range of machines

including AMADA, TRUMPF, WHITNEY, BISTRONICand more. In addition, the Nesting software pack-age provides a complete solution for interactive

and automatic nesting of different true-shape pat-terns. The Windows-based application is compati-ble with a wide range of CAD/CAM systems (DXF,IGES, CADL). The pace of change in engineering

and scientific computers, CAD/CAM and CAE, andrapid prototyping presents you with a dilemma.You have to make the most of the tools you

already have, while keeping up with new tech-nologies that are revolutionizing the market inwhich you compete.Reports on manufacturing defects, so you can avoid

systems with faulty chips and boards. Technical

computing differs from business applications. Engi-neers, scientists, economists, and other technicalprofessionals perform numerically intensive tasks.Designers of products, plants, buildings, and enter-tainment media need fast graphics performance to


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brze grafi~ke performanse da bi radili efikasno.Korisnici tehni~kih prora~una ne trebaju da se neke

periode posve}uju aplikacijama kao {to suprora~uni, knjigovodstvo, bankarstvo, osiguranjeprava u procesu i obnova. Oni trebaju i to zasluùju

jedan newsletter posve~en unikatnim zahtjevimatehni~kih profesionalaca. Trasiranje ta~nih i detaljnihinformacija o mena|mentu podacima proizvoda (PDM ) kao sistema je vrlo te{ko. Razli~iti magazini

izvje{tavaju o raznim temama u procesu konstru-isanja, pa ~ak njihove korice su ~esto koloritne dabi zainteresovale dizajnere. To je tako|e skupo jerPDM sistem je takav sistem koji mora odgovarati

specificiranim aplikacijama.Zato je potrebno izna~i iprepoznati na osnovu iskustva stvarni PDM sistemkoji radi pouzdano, a izbje}i onaj koji ne odgo-vara.Ovaj rad pomaè u ovakvoj odluci , ali i kada

se mjenja pejza` PDM sistema. On {tedi vrijemebudu}i su prezentovane informacije koje su potreb-ne da bi konstruktori i projektanti donijeli praveodluke. Ovo je odgovor i na dilerove zahtjeve, a bal-

ansira i propagandne istupe.Na taj na~in ima se prava informacija, a da se ne

gubi previ{e vremena oko toga. Informacije dobiveneiz ovog ~lanka tako|er obezbje|uju izbjegavanjevendora i tehnologija koje ne mogu ili ne}e zado-voljiti trenutne ali i budu}e zahtjeve dizajnera.Tako|er obuhvataju i ko{tanje i proizvodne trendove

u mnogo detalja, daju}i spoznaje pri pregovaranju onabavci nekog softvera. Naravno svaki dizajner bibio prezadovoljan kada bi postojao jedn tim ekspe-rata da analizira sve promjene, da osigura uvijek radsa najboljim raspoloìvim tehnologijama, i da nikadne investira u novi proizvod prije nego otkloni svebagove u njemu. Mnogi ovakvi radovi daju}i ~itaoci-ma prave informacije u poslovnim i dizajnerskimtrendovima predvidili su i kolaps nekoliko biv{ihCAD/CAM industrijskih predvodnika, prije nego {to

su i do{li u probleme. U 1988 godini neki CAD

~asopisi sa entuzijazmom opisali su Pro/ Engineer,koji je tada bio jedan novi solid modeling softver,iz male firme zvane Parametric Technology. Danas,PTC je vode}a industrija u prodaji softvera za solid

modeliranje, i ostvaruje ogromne profite za razliku odmnogo drugih koje jedva preìvljavaju.Vrativ{i se nazad u 1983 godinu mnogi dizajneri su

se sve vi{e okretali ka personalnim ra~unarima ipredvi|ali da }e i CAD i CAE sistemi biti popularniba{ na ovim platformama. U 1991 godini neki dizaj-neri su objasnili za{to }e i veliki gigant poput IBM-a do}i u te{ko~e, jer nije ispo{tovao strategiju

kupaca u hardverskom i softverskom smislu, a kojesu bile poznate 1990 godine.CAD radovi pravilnogovore kako inovirati CAD/CAM tehnologije u ciljupodizanja produktivnosti. Oni izvje{tavaju kojeaplikacije vra~aju najve}u korist, i {to je jo{ bitnije


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work efficiently. Technical computing users don'tneed to wade through periodicals devoted to appli-cations such as accounting, banking, insuranceclaims processing, and retailing. They do need anddeserve a newsletter devoted to the unique

demands of technical professionals.Tracking downaccurate and detailed information about product datamanagement (PDM) systems is hard. Trade maga-zines barely report on the topic, and even whenthey do, their coverage is often colored by the inter-ests of advertisers. It's also costly to benchmarkPDM systems side-by-side because they must becustomized to your specific application. You need tofind out from the experience of actual PDM userswhich PDM systems work reliably and which you

should avoid.This paper helps you keep up with the ever-chang-

ing landscape of PDM. It saves you time becauseit presents the information you need to make deci-sions and explains the details that other publica-tions gloss over. It casts a critical eye on vendorclaims, balancing corporate propaganda with verifi-

able case histories. You stay informed withouthours of reading.The information you get frompaper e will help you avoid vendors and tech-nologies that can't or won't meet your current andfuture needs.Also covers pricing and producttrends in detail, giving you an edge in purchasing

negotiations. Wouldn't it be great if you could relyon a team of experts to analyze these changes, to

help ensure that you're always working with thebest technology available, and that you never investin new products before the bugs have beenworked out? Of course, yes.Keeping readers alert to business trends that might

jeopardize their investments, these papers and jour-nals predicted early the collapse of several formerCAD/CAM industry leaders before their troubles

became widely known. In 1988, CAD"s journals enthu-

siastically described Pro/Engineer, what was then anew solid-modeling product from a small firm calledParametric Technology. Today, PTC leads the industry

in sales of solid-based design software, while whatwere once billion-dollar competitors struggle for sur-vival. Way back in 1983, many designers foretold thedecline of turnkey CAD and predicted personal com-

puters would become popular platforms for CAD andCAE. In 1991, some designers explained why even

giants like IBM are no longer safe buys, and we out-lined hardware and software purchasing strategies

suitable for the 1990s. The CAD papers regularly tells

how innovative CAD/CAM owners are using the tech-nology to boost productivity and save money. Itreports which applications yield the highest return,and -- just as importantly -- which should be avoid-ed with today's systems. They also write about soft-


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koje bi trebalo izbje}i za dana{nje sisteme. Onitako|er pi{u kao i ovaj ~lanak o softveru koji upravl-

ja i kontroli{e CAD/CAM podatke u svim elektron-sko inènjerskim uredima.Tako|er u mnoge poslove dizajniranja investirana su

ogromna sredstva u cilju brzog prototipisanja sistemasamo da se otkrije da li ne{to moè funkcionisati iline, ili je to ve} poznato. Rad pomaè upravo da seizbjegnu takve gre{ke i da se prepoznaju oneCAD/CAM tehologije i PDM sistemi koji daju ~vrstinuu odluci i daju va`ne informacije u ovoj oblasti,

kako bi se predvidile sve tehnolo{ke prednosti nekogtek potencijalnog sistema za kori{tenje. Najva`nije,

rad daje jasnu sliku koje su postoje}e industrije soft-vera najefikasnije za dana{nje okruènje, kako bi se

moglo planirati {ta ~initi u budu}nosti. Novi razvoji umemoriji, mikroprocesorima, multiprocesorima, plote-

rima i input /output ure|ajima obezbje|uju najboljeperformanse i pouzdanost uz minimalne tro{kove.Osim toga, prilagoditi najnovije operativne sisteme,uklju~uju}i tu i Windows 95 i Windovs NT i razvoje

koji jo{ uvijek mogu dati budu}nost UNIX-u.Ovaj rad je i pronalaza~ kad ne{to u~initi pa i plati-ti premiju za UNIX ili Microsoft Windows NT, a kadato ne ~initi.Isto tako tutoriali na mreàma, grafi~ki dis-

pleji i multiprocesing sistemi omogu}uju da se proc-jeni koja od ovih tehnologija radi najbolje za odre|enuaplikaciju. Grafovi budu}ih kompjuterskih vrijednosti

tako|er usmjeravaju za izbor najoptimalnijeg sistema iizbjegavanje onih sistema koji su preskupi. Trì{te dijelii finansijske podatke za vode}e tvorce kompjutera,tako da je i to jedan od pokazatelja koje tehnologije

nestaju odnosno odumiru. Sistem PDM obuhvata dakle{iroko podru~je tematskih cjelina a sve sa ciljem dadizajneri budu dobro informisani u svako vrijeme, a to

se prvenstveno odnosi na:

Nau~iti kako staviti pod kontrolu tro{kove, Istraìti kako druge firme su koristile PDM

sistem i da li efikasno, Monitoring finansijskog stanja PDM softverkompanija, da bi se izbjegli mogu}iproblemi,

Prou~iti koji PDM snabdjeva~i su u vrhu novihtehnologija, a koje su u padu,

Razumjeti koji standardi oblikovanja seprimjenjuju u PDM sistemu razvoja proizvoda,

Odrediti koji PDM softver je najbolji za trenutnepotrebe neke kompanije,

Izu~iti kako su drugi upravljali nekimfunkcijama PDM zahtjeva,

Pripreme za PDM softver pomo}u smjernicaprocesa i maping radni tok,

Izbje}i PDM provo|enje gre{aka koje buduotkrivene,

Prona}i kako male,srednje i velike kompanije


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ware to help you manage and control CAD/CAM datain an all-electronic engineering office.Too many businesses have invested hundreds ofthousands of dollars in a rapid prototyping systemonly to discover that it can't do what they believed

or that it is already obsolete.The paper helps youavoid such mistakes by printing in-depth, objectiveappraisals of the strengths and weaknesses of eachtechnology and keeps you aware of important new

research and development activities and interpretsthis research so you can foresee technological

advances.Most important, paper gives you the big picture ofwhere this exciting new industry is heading, so youcan plan for the future. New developments in mem-ory, microprocessors, multiprocessing, plotters, and

input/output devices that boost performance and

reliability while lowering prices. Updates on the lat-est operating systems, including the maturing ofWindows 95 and Windows NT, and developmentsthat may yet give Unix a future.Discover when it makes sense to pay premiums forUnix or Microsoft's Windows NT and when you don't

need too. Tutorials on networking, graphics displays,and multiprocessing systems, so you can evaluatewhich of these technologies works best for your

applications. Graphs of future computer values soyou can dispose of existing systems at fair prices

while avoiding paying too much for used systems.Market shares and financial data on leading com-

puter makers so that you don't risk getting strand-ed with a technology that's dying. Product DataManagement covers a wide range of topics and

you'll be armed and ready to get the best dealevery time and it will help you: Learn how to put the brakes on out-of-controlspending.

Find out how other firms have used PDMsystems effectively.

Monitor the financial health of PDM softwarecompanies, so you don't get stuck with afinancially troubled supplier.

Learn which PDM suppliers are on the cuttingedge of technology and which are falling behind. Understand how standards are shaping PDMproduct developments.

Determine which PDM software products arebest for your company's needs and budget.

Learn how others have managed cross-functional PDM requirements.

Prepare for PDM by streamlining processes and

mapping workflow.Avoid PDM implementation mistakes that can

wreck your career. Discover how small, medium, and large

companies budget for PDM.


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ulaù u PDM sistem, Izu~iti kako objasniti PDM koncepte jednostavnomenadèrima i ostalim korisnicima,

Za{tititi investicije pomo}u osiguranja da PDMsistem uvijek bude pouzdan,

Upore|ivati vlastiti PDM napredak sa drugimkompanijama.

Implementacija i kori{tenje PDM sistema je rizi~no ikompleksno, ali PDM pomaè da se minimiziraju ovirizici daju}i niz informacija. Ako PDM pomogne dase izbjegnu npr. gre{ke na nekoliko crteà, u{tededaleko nadma{uju uloèna sredstva u PDM sistem.

4.ZAKLJUÂKNajefikasniji op{ti alati za ovaj proces konstruisanja

su kompjuterski sistemi. Specifi~niji kompjuterski sis-temi su potrebni onda kada inkorporiraju i modeli-

ranje alata baziranog na proizvodnim naukama. Ovamodeliranja alata moraju nas snabdjeti sa dovoljnimmogu}nostima za ta~nost i korektno kreiranje mod-ela na{e industrijske realnosti i sa njihovim proizvodi-

ma, trì{nim uslovima, konstrukcijama, alatnimma{inama,upravljanje sistemima i ergonomskim zaht-jevima. Ovi modeli i kompjuterski podràni sistemibazirani na njima moraju biti razumljivi za inènjere.

Uspje{an dizajn proizvoda zahtjeva realizaciju neko-liko razli~itih koraka. Za primjer, jedan dizajn proces

moè involvirati korake takve koji su spregnuti sapotrebama kupca i osiguranjem toga oni su podesnoformulisani kao jedan dizajn problem, zatim dekom-

pozicija velikog problema u zadatke veli~ine sa koji-ma je mogu}e upravljati,,zatim dodjela zahtjevnimzadacima aktivnih sudionika na svakom zadatku iosiguranje da rezultati proizvedeni pomo}u zahtjevnih

zadataka su integrativni i prihvatljivi.Svaki korak je poduzet od dizajn predstavnika, soft-

verskih alata, ili kombinacija i jednog i drugog. Inte-gracioni alati i ljudstvo i dodjeljena uloga svakom odnjih su kriti~ne faze za uspje{no kompletiranje proce-sa konstruisanja. Postoje}i konstruktorski sistemi teèupotrebi razli~itih struktura za ljudstvo i za softverske

alate ( CAD alati ). U cilju humanosti , npr arhitektedopu{taju i predplaniranje i spontanu kolaboraciju

izme|u alatki u formi grupa, komiteta i timova. Kaorezultat, fleksibilnost je relativno visoka.U suprotnom,kreacija kompleksnih organizacija softverskih alata jejedan teàk zadatak. Relativni nedostatak fleksibilnihsoftverskih mjesta alata ne{to teè nagla{ava ljudsku

ulogu u procesu konstruisanja. Me|utim, uve~avaju}ikompleksnost dizajna i potrebe za kra}im dizajn cik-lusom zahtjeva od dizajnera, da se pitaju kakvi mogu

biti oni iza njihovih sposobnosti .Premda, softverskialati i dizajneri trebaju biti u kooperaciji i zajedni~ki


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Learn how to explain PDM concepts simply tomanagers, peers, and subordinates.

Protect your investment by ensuring that PDMsystems are used wisely.

Compare your PDM progress against other

companies.

Implementing and using PDM systems is risky andcomplex and the PDM helps you minimize those

risks by giving you information . If the PDM helpsyou avoid a six-figure mistake, it will have paid foritself hundreds of times over.

4.CONCLUSIONThe most efficient general tools for this design work

are computer systems. More specifically, computersystems are needed which incorporate modellingtools based on manufacturing science. These mod-elling tools must provide us with sufficient possibil-

ities for accurately and correctly creating models ofour industrial realities with their products, marketconditions, buildings, machine tools, handling sys-tems and working human beings. These models andthe computer support systems based on them must

be understandable for engineers. The successfuldesign of a product requires the realization of sev-

eral distinct steps. For example, a design processmay involve steps such as capturing the customers"needs and ensuring they are properly formulated asa design problem; decomposing the overall probleminto tasks of manageable size; assigning a taskforce of active agents to each task; and ensuringthat the results produced by the task forces are

integrated into an acceptable, overall solution.Each step is undertaken by human agents, softwaretools, or a combination of both. The integration oftools and humans and the assignment of the roleto each one of them are critical phases for the suc-cessful completion of the design process. Existingdesign systems tend to use different structures for

humans and for software tools ( CAD tools ).For humans, architectures allow for both preplanned

and spontaneous collaborations among the tools inthe form of groups, committees and teams. As a

result, flexibility is relatively high. In contrast, the cre-ation of complex organizations of software tools isa difficult task.The relative lack of flexible software tools places a

heavy emphasis on the human"s role in design sys-

tems.However, the increasing complexity of designsand the need for shorter design cycles demandfrom humans what may be beyond their capabilities.Thus, software tools and humans need to be ableto co-exist and cooperate in a design environment.


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egzistirati u jednom dizajn okruènju. Jedno mogu~erje{enje problema integracije alata i dizajnera obuh-vata tri linije rada: prvo, razvoj fleksibilnosti, dvodi-

menzionalne strukture u kojima alati mogu brzo ilagano biti integrisani; drugo, postizanje alata sposob-

nih da u~estvuju u ovim strukturama; i tre}e, razvojkontrolnih shema za operisa-nje rezultuju}im organi-zovanjima.Glavna namjera ovog rada je pobolj{ati efikasnost

procesa konstruisanja i kvaliteta rezultuju}ih dizajna. Zaproizvodnu industriju odgovoriti ~ak uve~anim zahtjevi-ma, za fleksibilnost, kvalitet, brzinu i ekonomiju, kon-struktori moraju znati kako primjeniti moderneprora~une i automatizaciju tehnologije. Dizajn i plani-ranje proizvodnih sistema je jedna aktivnost ogromnogzna~aja za industrijske konkurentnosti. Zdrave analizepomaù modeliranje i proces planiranja i to je klju~

postizanja efikasnih operacija takvih sistema. Strogaoptimizacija metodologija i ta~no modeliranje tehnike

propusta, u mnogim slu~ajevima, adresiraju ogromnukompleksnost proizvodnog sistema. Integracija dizajna iproizvodnje je va na ne samo za ve}u efikasnost, negotako|e pobolj{ava kvalitet i u dizajnu i u proizvodnji.Moderni proizvodni sistemi su visoko tehnolo{ki alati

koji nas snabdjevaju sa sredstvima produciranja fizi~kihproizvoda sa funkcijama koje ta~no predstavljaju indi-vidualne potrebe razli~itih korisnika. Ovi sistemi,

podesno kori{teni, daju nam prakti~ne, produktivne

mogu}nosti postizanja korisnikove prilago|eneproizvodnje direktno prema naru|bi. Kupca Jedan per-spektivni dizajn ovih sistema daje nam mogu}nostadaptiranja sistemskih performansi prilago|enih zahtje-vima radnika i proizvodnih planera. U ovom slu~ajuljudski faktor postaje jedan vaàn sastojak u uspje{nojoperaciji modernih proizvodnih sistema.

LITERATURA - REFERENCES[1] Obermann, K.: CAD/CAM, Handbuch, VerlagComputergrafik GmbH, Muenchen, 1995.

[2] Williams, D:J.: Manufacturing Systems, Chapmanand Hall, London, 1992.

[3] Lee, M.H.: Intelligent Robotics, Chapman andHall, London, 1991.

[4] Knight, P.T., Kim, H.S.: A knowledge system forintegrated product design, Journal of Intelligent Man-ufacturing, London,1991.

[5] Rep~i}, N.: CAD metode, Ma{inski fakultet Sara-jevo, Sarajevo, 1996.

[6] Hasegawa, Y.: Evaluation and Economic Consid-erations, Handbook of Industrial Robotics,,

John Wiley & Sons, New York, 1988.


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A possible solution to the problem of integrating toolsand humans involves three lines of work; first, todevelop flexible, two dimensional structures into whichtools can quickly and easily be integrated; second,to obtain tools capable of participating in these struc-

tures; and third, to develop control schemes for oper-ating the resulting organizations.The main purpose ofpaper is to improve the efficiency of the designprocess and the quality of the resulting designs.For manufacturing industries to respond to ever

increasing demands, for flexibility, quality, speed andeconomy, they must know how to apply moderncomputing and automation technology.The design

and planning of manufacturing systems is an activ-ity of immense importance for industrial competi-tiveness. Sound analysis to support the design and

planning process is the key to achieving efficient

operation of such systems.Strict optimization methodologies and exact model-

ing techniques fail, in many cases, to address thetremendous complexity of the manufacturing sys-tem.The integration of design and manufacture is

important not only for greater efficiency, but also toimprove quality in both design and manufacture.Modern manufacturing systems are high technolo-

gy tools that provide us with the means to producephysical products with functions that accurately meetthe individual needs of the various customers.

These systems, properly utilized, give us practical, pro-ductive possibilities to achieve customer adapted pro-duction directly upon customer order. A perceptivedesign of these systems gives us the possibility to

adapt system performance to suit the requirements ofthe workers and production planners. In this way

human factors become an important ingredient in thesuccessful operation of modern manufacturing systems.

[7] Maddux, K.C., Jain, S.C.: CAE for the manufac-turing engineer, Manufacturing Simulation andProcesses, ASME,20, New York,1990.

[8]Jackson, P., Reichgelt, H.: Logic Based Knowl-edge Representation, The MIT Press, Cambridge,USA,1991.

[9] Kochan, D.: CAM developments in computerintegrated manufacturing, Springer Verlag, Berlin,1992.

[10] Cheng, Y.Q., Yang, J.Y.: An expert system forunderstanding assembly drawings, Advances in Mod-

elling and Simulation, 21, 1991.[11] Web site-http:// www. cad/cam.com / science /engineering / design /

Documents

Jedan Prikaz Okruzenjapri Procesu Konstruisanja