Spelling suggestions: "subject:"gantry cranes"" "subject:"pantry cranes""
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Modelagem paramétrica de pórticos rolantes: estabilidade estrutural e otimização. / Gantry cranes parametric modeling: structural stability and optimization.Gustavo Sobue 29 July 2005 (has links)
O objetivo deste trabalho é desenvolver uma ferramenta de automatização de cálculo para projeto estrutural de pórticos rolantes. Com o apoio da geração automática de um modelo de elementos finitos e um memorial de cálculo, o projeto estrutural desses equipamentos pode ser rapidamente verificado quanto ao limite de escoamento do material e resistência à flambagem. Optou-se pela utilização do método dos elementos finitos para o cálculo estrutural, pois se trata de uma ferramenta de cálculo moderna, que permite avaliar soluções para as quais não há ferramentas analíticas disponíveis. Porém, o tempo para geração de modelos de cálculo pode ser longo em relação ao cronograma do projeto, principalmente se houver a necessidade de se alterar a geometria inicial ou se existirem várias condições de carregamento a serem analisadas. A utilização de um pré-processador permite que várias alternativas sejam analisadas para escolha da que melhor atenda aos requisitos de projeto e de custo. Assim como ocorre com outras estruturas de engenharia, não existe uma equação de dimensionamento, mas sim de verificação; as estruturas ótimas são procuradas por tentativa e erro com base na experiência do projetista. Para facilitar a busca de uma estrutura ótima, implementou-se também uma rotina para otimizar as estruturas metálicas do pórtico. Adotou-se como função objetivo nesta implementação a minimização da massa, o que no caso dos pórticos implica em redução da área da seção transversal das vigas. Como restrições a esta redução adotaram-se o limite de escoamento do material e limite de estabilidade da estrutura (flambagem). Foram utilizados os aplicativos Excel (Microsoft), Ansys (Ansys Inc.) e Mathcad (Mathsoft) de maneira integrada a fim de se obter uma interface amigável, uma análise estrutural confiável e a elaboração automática de um memorial de cálculo. / The objective of this work is to develop a tool to generate an automatic structural design of gantry cranes. With an automatic generation of finite element models and also a design report, this routine allows a fast verification against yield of material and structural instability. The use of the finite element method was chosen for the structural design because it is a modern analysis tool that permits the evaluation of geometric configurations for which there are no analytical formulations available. However, the time necessary to build these models may be high, especially if there are changes in the initial geometry and many load cases. The use of a pre-processor allows the evaluation of a series of geometric alternatives, within which would be chosen the one with the lowest cost that attends the clients specifications. Like many other engineering problems, there are no direct equations to find an adequate structure; there are only verification procedures available; the optimum structures are searched by trial and error, based on the designers experience. To accelerate this search process, an optimization routine was developed. Mass reduction was adopted as the objective function, which leads to reduction of the cross section area of the beams. Yield strength and buckling were adopted as restrictions to this optimization. Excel (Microsoft), Ansys (Ansys Inc) and Mathcad (Mathsoft) software were integrated to provide an user-friendly interface, reliable structural analysis and an automatic report generation.
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Jeřáb pro manipulaci s leteckými agregáty / Aviation maintenace craneBureš, Martin January 2013 (has links)
This master´s thesis solves design of a mobile crane for handling air aggregates and ejection seats. Handling crane provides lifting a maximum weight of 300 kg to a height of 4600 mm. Subject of the work is the choice of appropriate technical solutions, design of lifting mechanisms, supporting structures and accessories. The suitability of the solution is checked by strength analysis of individual units. Another task is to provide mobility equipment and control stability against overturning. The appendix includes protocols static analysis of the program Nexis32, drawing overall crane assembly and manufacturing drawings selected parts.
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Development of a crane load software application for electric driven overhead travelling bridge cranes in accordance with SANS 10160-6:2010De Waal, Arthur William 03 1900 (has links)
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Electric driven overhead travelling bridge cranes (EOHTC) form a vital part of industrial plants
where heavy objects require moving. Overhead travelling cranes aid in production by allowing
an uninterrupted work process on the ground while heavy loads are moved to their required
locations.
Various factors need consideration in determining the loads induced by an EOHTC on its
support structure. In order to design such a support structure, the designer must understand
and take into account the various loads that the support structure will be subject to during its
lifetime.
The procedure for determining the loads induced by the EOHTC on its support structure is laid
out in the SANS 10160-6:2010 code of practice. This document was published in June 2010
and as a result very few worked examples exist to test the coherence of the procedure.
This thesis presents an investigation into the procedure for determining the actions induced by
overhead travelling bridge cranes adopted in the SANS 10160-6:2010 code of practice. The
investigation was conducted by developing a software application to automatically determine the
necessary crane actions needed for the design of the crane support structure, given certain
input parameters. The motivation behind this was to have a tool that can calculate the crane
induced loads automatically. And by developing such a tool the procedure given in the code of
practice is better understood.
The Java programming language was used to code the calculations with an object oriented
programming approach (OOP). NetBeans, the integrated development environment for
developing with Java was used to generate the required graphical user interface of the
application. In addition, a Microsoft Excel calculation sheet was also developed for the purpose
of comparison and verification.
Whilst developing the software application, it was found that the model for the acceleration or
deceleration of the crane was specific for four wheel cranes only. This model was then extended
to accommodate eight and sixteen wheel cranes and incorporated into the algorithm
architecture of the application. The application was successfully completed and verified using benchmarked examples. / AFRIKAANSE OPSOMMING: Elektriese oorhoofse brugkrane vorm ‘n belangrike deel van baie nywerheidsprosesse, waar dit
gebruik word om swaar laste in die nywerheidsaanleg te verskuif. Oorhoofse brugkrane voeg
waarde by die produksie lyn deur te sorg dat die werksproses op die grond onversteurd
voortgaan terwyl swaar laste na hul vereiste posisies verskuif word.
Verskillende faktore moet in ag geneem word om die nodige kraanlaste te bepaal. Hierdie laste
word benodig om die kraan se ondersteuningstruktuur te ontwerp. Die ontwerper moet die
nodige kundigheid hê en moet ook die verskeie laste in ag neem wat die ondersteuningstruktuur
gedurende sy leeftyd sal dra.
SANS 10160-6:2010 verskaf riglyne vir die bepaling van die laste wat deur oorhoofse brugkrane
uitgeoefen word. Hierdie dokument is in Junie 2010 gepubliseer dus bestaan daar min
uitgewerkte voorbeelde om die korrektheid van die riglyne te toets en toepassing te
demonstreer.
Hierdie proefskrif ondersoek die riglyne vir die bepaling van oorhoofse brugkraan aksies soos
uiteengesit in die SANS 10160-6:2010. Die navorsing is uitgevoer deur middel van die
ontwikkeling van ‘n sagteware toepassing wat die nodige oorhoofse brugkraanlaste automaties
bepaal, gegee sekere invoer waardes. Die rede hiervoor was om ‘n hulpmiddel te ontwikkel vir
die outomatiese bepaling van oorhoofse brugkraan. Deur die bogenoemde hulpmiddel te
ontwikkel word die riglyne, soos gegee in die kode beter verstaan.
Java is gebruik as programmeringstaal waar die objek geörienteerde programeringstyl toegepas
was. Die geintegreerde ontwikkelingsomgewing vir ontwikkeling met Java, naamlik NetBeans is
gebruik om die nodige gebruikers koppelvlak op te bou. ‘n Microsoft Excel sigblad is ook
ontwikkel vir kontrolerings doeleindes.
Gedurende die ontwikkeling van die sagtewarepakket is dit bevind dat die lasmodel vir die
versnelling of vertraging van die oorhoofse brugkraan slegs op vierwiel krane van toepasing is.
Hierdie lasmodel is dus uitgebrei om agt- en sestienwiel krane ook te bevat. Die lasmodel
aanpassing is dan ook in die program se algoritme-argitektuur ingebou. Die sagteware toepassing is suksesvol ontwikkel en gekontroleer met ‘n maatstaf voorbeeld.
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