The finite element analysis of irradiation induced stresses in graphite core components of a nuclear reactor

Imperial Users onl

A feature-based approach to conceptual design process

Konstruiranje je zahteven miselni postopek, poln inženirskih odločitev in ponavljanja. Običajno začne z ugotavljanjem in določanjem potreb - zahtev, sledi mu iskanje najboljše rešitve zadanih nalog, ter po izbiri ustrezne rešitve še dodelava s podrobnim opisom izdelka. Izvajajo ga ljudje - konstrukterji, ob čedalje močnejši računalniški podpori. Žal v tem postopku pomembna faza iskanja - t.i. faza zasnove, ni deležna ustrezne računalniške podpore, predvsem zaradi zapletene in neformalne oblike podatkov, ki jih je težko računalniško modelirati in obdelovati. Sodobni računalniški sistemi za podporo konstruiranja modelirajo predvsem geometrijske podatke, potrebne predvsem v postopku določanja izdelkov kot pri izdelavi. V fazi zasnove pa so podatki bolj abstraktni in se nanašajo predvsem na funkcije izdelkov ter njihove izvedbe. Zato avtorja predlagata uporabo značilnosti za modeliranje podatkov v fazi zasnove izdelka. Funkcijske značilnosti bodo omogočile opisovanje, zbiranje, shranjevanje in obdelavo podatkov o funkciji izdelka že v fazi zasnove, hkrati pa povezavo z nadaljnimi fazami konstrukcijskega postopka.Product design is an iterative, complex and decision-making process, performed by designers. It usually starts with recognition and specifying requirements and demands, followed by searching for an optimum solution, for the required tasks. After an evaluation of the concept solutions and the selection of promising solutions comes detailing with the layout definition, and a description of the product. Conceptual design has been recognised as an important part of the design process, but receives weak computer support due to complex and informal data that is hard to retreive, store and maintain with computers. Besides geometrical data, it is important to capture, represent and process the function and the behaviour of a product. The presented approach is future-based modelling of product semantics and function that takes place already in the conceptual design phase. The features are taken the information carriers that allow modelling of the relationship between the requirements of a product, its functional description and physical solutions. These features will also bring this information to the downstream applications

Experiences of CAD implementation and trends in development at ADRIA Mobil Ltd.

Adria-Mobil d.o.o. je znano slovensko podjetje poćitniških prikolic in avtodomov, ki se je za uvajanje dvodimenzionalnega sistema računalniško podprtega konstruiranja (RPK - CAD) odločilo že pred leti. V članku je opisan način uvajanja, pa tudi izkušnje, pridobljene ob uvajanju in uporabi sistema RPK. Danes je podjetje prisiljeno v menjavo sistema RPK in se srečuje z nekaterimi dilemami, ki so posledica hitrega razvoja sistemov informacijske tehnologije (IT) pa tudi pridobljenih spoznanj. Pred nadaljnimi investicijami v napredne tehnologije mora biti določena strategija podjetja na tem področju.Adria-Mobil Ltd. is a well known Slovenian caravan and motorhomes producer, which introduced a 2D CAD system some years ago. In the article, the implementation, development and experiences since are system\u27s introduction are described. The company is about to change its CAD system and is faced with certain dellemas due to rapid IT-systems development. A company strategy is required before making any major advanced-technology-related investment decisions

Polygon trapezoidation by sets of open trapezoids

A new efficient algorithm is described for the simple trapezoidation of polygons based on a sweep-line paradigm. As the sweep-line glides over the plane, a set of so-called open trapezoids is generated and maintained. It is shown that a boundary case (more polygon vertices are located on the sweep-line) can be solved safely and does not slow down the algorithm. If desired, the polygon holes can be trapezoidated simultaneously. This proposed algorithm when compared with the fastest known algorithm developed by Seidel resulted in more efficiency for different classes of polygons