This PhD thesis deals with employment of the state of the art methods of mathematical optimization and structural analysis in the field of load carrying steel structures of handling devices. The goal of the thesis is to compile a methodology which enables generating of optimal dimensions of conceptually designed load carrying parts of handling devices. The proposed methodology is composed of sub-methods which are successively applied to find an optimal configuration of structure according to a chosen criterion. The methodology incorporates sub-methods such as Design of Experiments, parametric finite-element modelling, the state of the art computational methods for stability assessment, mathematical approximation methods and state of the art optimization schemes based of both, heuristic and gradient principle. Recommendations from Eurocode 3 are used to introduce imperfections to the finite element model in order to perform the nonlinear buckling analysis. The practical part of this thesis is focused on optimization of welded beams. The principle of the methodology is in detail explained and demonstrated on an example of lifting spreader beam of load carrying capacity of 20 tons. The proposed methodology is practically realized by an algorithm created in Matlab software. Matlab is also utilized to implement some sub-methods including mathematical optimization schemes. Both, gradient and heuristic optimization algorithms are used for comparison and mutual verification. Structural analysis is performed by means of parametrical finite-element models which are built in the Ansys Parametric Design Language (APDL). The methodology takes into account buckling, which is inherent to thin walled structures under compressive load. The buckling analysis is performed by means of both, linear and non-linear procedures in Ansys. The output of the algorithm is an optimized configuration of the structure, which minimizes the objective function and complies with all requirements implemented in the form of design constraints.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:234422 |
| Date | January 2015 |
| Creators | Šťastný, Antonín |
| Contributors | Hrabovský, Leopold, Kuľka,, Jozef, Škopán, Miroslav |
| Publisher | Vysoké učení technické v Brně. Fakulta strojního inženýrství |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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