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Design of pedal system for Pneumobil race car using topology optimisation
Pchálek, Václav ; Červinek, Ondřej (referee) ; Vaverka, Ondřej (advisor)
This thesis deals with design of pedal assembly of pneumobile racing car to increase its rigidity and reduce its weight. Based on the search, the kinematics of pedal was changed due to more precise determination of pedal ratio. Topology optimization and lattice structure were used to achieve the goals. The results were checked by strength analysis using finite element method. To produce topologically optimized parts use of metal additive technology is assumed, for which the parts have been further modified. Deformation was reduced by 13,4 % for the brake pedal and by 96,8 % for the accelerator pedal. The weight of the pedal system has been reduced by 31 %. This pedal assembly design could be an alternative to the current pedal assembly, as it is lighter and meets the requirements for higher rigidity.
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Design of auxetic structures for the selective laser melting technology
Pchálek, Václav ; Hutař, Pavel (referee) ; Červinek, Ondřej (advisor)
With the development of additive technologies, it became possible to produce auxetic structures with complicated geometries. Despite their intensive study, their potential for high resistance to local loading has not yet been explored. Describing this phenomenon and its causes would enable the effective design of structures with greatly enhanced resistance to foreign object impact. Therefore, this work investigated the deformation behavior of auxetic re-entrant honeycomb structures under local loading. The relationship between the resistance of the structure to local loading and the magnitude of the negative Poisson´s number, which was controlled by the geometry of the basic cell, was investigated. An analytical approach was used to determine the Poisson´s number of the structures. Subsequently, a prediction of the local loading behaviour of the structures was made using the finite element method assuming small and large deformations. This behavior was then experimentally verified for small and large strain rates on structures fabricated by selective laser melting technology. It was found that for the assumption of small deformations, the smaller the Poisson´s number of the structure, the more resistant it is to local loading. However, this does not apply to the assumption of large deformations, where the wall interaction and its buckling were difficult to predict. Furthermore, structures with thinner walls were shown to deform more, thus using their full deformation potential and therefore being more resistant to local loading. When tested at both low and high strain rates, a rearrangement of the structure towards the impact location was observed in two directions, perpendicular and against the direction of loading. It was found that structures with different geometry but the same Poisson's number have the same deformation behavior in terms of strain rate and reaction force. The findings of this work contribute to the understanding of the behaviour of auxetic structures under local loading, which can be used in the design of such loaded structures in specific applications.
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Design of pedal system for Pneumobil race car using topology optimisation
Pchálek, Václav ; Červinek, Ondřej (referee) ; Vaverka, Ondřej (advisor)
This thesis deals with design of pedal assembly of pneumobile racing car to increase its rigidity and reduce its weight. Based on the search, the kinematics of pedal was changed due to more precise determination of pedal ratio. Topology optimization and lattice structure were used to achieve the goals. The results were checked by strength analysis using finite element method. To produce topologically optimized parts use of metal additive technology is assumed, for which the parts have been further modified. Deformation was reduced by 13,4 % for the brake pedal and by 96,8 % for the accelerator pedal. The weight of the pedal system has been reduced by 31 %. This pedal assembly design could be an alternative to the current pedal assembly, as it is lighter and meets the requirements for higher rigidity.
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