Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (MEng) -- Stellenbosch University, 2004. / ENGLISH ABSTRACT: The purpose of this project was to study the deformations of the top flange and web of a girder panel resulting from loads, which have been imposed by an overhead travelling crane. This was achieved by designing a crane girder that represents dimensional ratios occurring in practice. The first part of this project attempts to determine the properties of the crane girder. The crane girder was built from drawings in the workshop of the University of Stellenbosch’s Civil-Department. Positions were identified where the strains were to be measured on the crane girder. The crane girder was subjected to loads according to SABS 0160 - 1989 and measurements were taken. The same beam was also modelled with finite elements. The numerical model was subjected to the same loads as the experimental crane girder. Comparisons were then made between the results of the experimental investigation and those of the numerical model. Good comparisons were achieved between the results and the numerical model was assumed to be correct. Other students could now use this model for investigating local stresses and strain effects that might cause fatigue and other in-service problems of electric overhead travelling cranes support structures in practice. / AFRIKAANSE OPSOMMING: Die doel van hierdie projek was om die vervormings van die boonste flense en web van ’n kraanbalkpaneel te ondersoek, as gevolg van laste wat onderworpe was aan ’n oorhoofse kraanbalk. Dit was bereik deur ‘n balk te ontwerp wat dimensionele verhoudings in die praktyk verteenwoordig. In die eerste gedeelte van die projek word die eienskappe van die kraanbalk bepaal. Die kraanbalk was vanaf tekeninge in die werkswinkel van die Universiteit van Stellenbosch se Siviele Departement gebou. Posisies was geidentifiseer waar die vervormings op die kraanbalk gemeet sou word. Die kraanbalk was onderwerp aan laste volgens SABS 0160 - 1989 en meetings was geneem. Dieselfde balk was ook gemodelleer met eindige elemente. Die numeriese model was aan dieselfde laste as die eksperimentele balk onderwerp. Vergelykings was toe verkry tussen the resultate van die eksperimentele ondersoek en die numeriese model. Goeie vergelykings tussen die resultate was behaal en die numeriese model word as korrek aanvaar. Ander studente kan nou hierdie model gebruik vir die ondersoek na lokale spannings en vervormingseffekte wat moontlik vermoeidheid en ander in-diens probleme van elastiese oorhoofse kraan ondersteunende strukture in the praktyk kan veroorsaak.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2007. / In structural engineering practice the actions imposed by overhead travelling cranes onto the supporting structure are defined as static forces amplified by dynamic coefficients and applied as pseudo-static forces without taking the interaction between crane and supporting structure into account. To investigate the validity of this approach, the forces generated at the wheels of an experimental crane are measured, as the crane traverses on the supporting structure. The interaction at the wheels of the crane is also visually recorded. These wheel load results will also be used by other researchers, to calibrate a numerical model of the experimental system. A full-scale 5 ton electric overhead travelling crane (EOTC) running on top of rails and a supporting structure, was designed and erected for research purposes. The crane has a span of 8.3 m and wheel spacing of 4 m, which can be modified. The supporting structure consists of three simply supported mono-symmetric plate girders on each side, with a total length of 13.8 m. This is supported by columns with a height of about 3.5 m. This paper describes the calibration of this system for measurement purposes. A data acquisition system was implemented to capture forces, strains, deflections and accelerations at various points on the crane and the supporting structure as well as to measure the velocity of the crane. The forces at the crane wheels are measured through strain gauges on the end carriage load measuring system. The calibrated facility is used to investigate the behaviour of the crane and the supporting structure under regular and exceptional wheel loads, which are classified as follows: - Regular wheel loads occur during normal payload hoisting and lowering, longitudinal crane travel with payload and lateral crab travel with payload. - Exceptional wheel loads occur during eccentric payload hoisting (payload outside normal operational area), impact forces on end-stops, maximum hoisting of the payload, failure of a longitudinal drive mechanism of the crane, misalignment of the supporting structure and skewing of the crane. The maximum values of these experimentally determined wheel loads and the dynamic response of the system is used to help describe the behaviour of the electric overhead travelling crane and its supporting structure.

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.