Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses.
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W pracy przedstawiono projekt wyciągarki bramowej firmy Elektrobudowa SA. Jest to jeden z kolejnych etapów wdrażania platformy montażowej w tym przedsiębiorstwie. Praca koncentruje się na wskazaniu dostosowania platformy montażowej dla produktu końcowego, jakim są rozdzielnie niskich, średnicy i wysokich napięć w firmie ELEKTROBUDOWA SA. Jest to ważny punkt procesu opracowania platformy montażowej oraz podejścia do wzorca rodziny produktów.
EN
The paper was presented project winch gantry the company ELEKTROBUDOWA SA. The project constitutes one of the stages of implementing an assembly platform in this firm. The publication shows the ways of adjusting the platform to the final product, which is low, medium and high voltage switchboards produced in the ELEKTROBUDOWA SA. The adjustment in turn is a vital point in the process of designing an assembly platform and approaching the pattern for a family of products.
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Gantry cranes of the shell structure are used in Polish steel industry much less than other gantry crane types. Those gantry cranes characterized by increased susceptibility to mechanical vibrations, resulting in greater sensitivity to the formation of fatigue cracks. In this work, measurements of strain gauge bridge deformation of the shells, for which periodically conducted non-destructive testing revealed the presence of numerous fatigue cracks mainly in the area of the under rail beams. Performed periodically repair and reinforcement of the crane did not eliminate the problem of the formation of the subsequent fatigue cracks. The analysis of the dynamic operation of the bridge, in combination with FEM calculations carried out showed stresses exceeding the limit value due to the fatigue phenomena. The results of dynamic analysis can serve as a basis to perform more accurate analysis of the fatigue life of the most intensive areas of the bridge.
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