National Repository of Grey Literature 7 records found  Search took 0.00 seconds. 
Analysis of Tube Bending Process
Šrom, Jan ; Řiháček, Jan (referee) ; Peterková, Eva (advisor)
Master thesis analyzes rotary draw bending of the tubes without using a mandrel. Bending process is accompanied by many defects due to large displacement of formed material. One of the major defects is flattering of the cross section also called ovality. In order to decrease ovality comes up a proposal of the changes to the tool design. Modifications of tool’s geometry are numerically analyzed by finite element method in software ANSYS. According to the results of the simulations an optimized pressure die is manufactured. Several experimental tests are accomplished to verify the effect of the optimized tool design. Approximately 100 bends confirm a decrease of ovality using modified pressure die.
Ovality measurement of extruded fiber using three cameras
Loučka, Pavel ; Martišek, Dalibor (referee) ; Štarha, Pavel (advisor)
One of the important parameters observed during extruded fibre fabrication is its diameter. The diameter can be measured with a single scanning camera assuming that the fibre section has a circular shape. As proved in practice, another important parameter is ovality, that is the rate of fibre flattening. This paper assumes that the fibre section shape is elliptical. In such a case, at least three different views on examined fibre are needed. Mathematical part of this paper is concerned with analytical description of fibre ovality measurement using two different approaches based on the knowledge of linear algebra, projective geometry and conic sections theory. Main goal of this paper is thus to use both mathematical theory and image analysis methods for ovality and diameter determination. Precise calcluation of such quantities is, however, conditioned on precise camera system calibration, which is described in the paper as well. Additionally, the work contains a brief mention of technical realization of ovality measurement and its possible difficulties.
Extruded fibers ovality measurement
Loučka, Pavel ; Procházková, Jana (referee) ; Štarha, Pavel (advisor)
One of the important parameters observed during extruded fibre fabrication is its diameter. The diameter can be measured with a single scanning camera assuming that the fibre section has a circular shape. As proved in practice, another important parameter is ovality, that is the rate of fibre flattening. This paper assumes that the fibre section shape is elliptical. In such a case, at least three different views on examined fibre are needed. This paper deals with analytical description of fibre ovality measurement using two different approaches based on the principles of linear algebra and projective geometry. As a result, a considerable part of the work is devoted to these branches of mathematics with particular regard to analytical conics theory. Additionally, the work contains a brief mention of technical realization of ovality measurement and its possible difficulties.
Ovality measurement of extruded fiber using three cameras
Loučka, Pavel ; Martišek, Dalibor (referee) ; Štarha, Pavel (advisor)
One of the important parameters observed during extruded fibre fabrication is its diameter. The diameter can be measured with a single scanning camera assuming that the fibre section has a circular shape. As proved in practice, another important parameter is ovality, that is the rate of fibre flattening. This paper assumes that the fibre section shape is elliptical. In such a case, at least three different views on examined fibre are needed. Mathematical part of this paper is concerned with analytical description of fibre ovality measurement using two different approaches based on the knowledge of linear algebra, projective geometry and conic sections theory. Main goal of this paper is thus to use both mathematical theory and image analysis methods for ovality and diameter determination. Precise calcluation of such quantities is, however, conditioned on precise camera system calibration, which is described in the paper as well. Additionally, the work contains a brief mention of technical realization of ovality measurement and its possible difficulties.
Extruded fibers ovality measurement
Loučka, Pavel ; Procházková, Jana (referee) ; Štarha, Pavel (advisor)
One of the important parameters observed during extruded fibre fabrication is its diameter. The diameter can be measured with a single scanning camera assuming that the fibre section has a circular shape. As proved in practice, another important parameter is ovality, that is the rate of fibre flattening. This paper assumes that the fibre section shape is elliptical. In such a case, at least three different views on examined fibre are needed. This paper deals with analytical description of fibre ovality measurement using two different approaches based on the principles of linear algebra and projective geometry. As a result, a considerable part of the work is devoted to these branches of mathematics with particular regard to analytical conics theory. Additionally, the work contains a brief mention of technical realization of ovality measurement and its possible difficulties.
Analysis of Tube Bending Process
Šrom, Jan ; Řiháček, Jan (referee) ; Peterková, Eva (advisor)
Master thesis analyzes rotary draw bending of the tubes without using a mandrel. Bending process is accompanied by many defects due to large displacement of formed material. One of the major defects is flattering of the cross section also called ovality. In order to decrease ovality comes up a proposal of the changes to the tool design. Modifications of tool’s geometry are numerically analyzed by finite element method in software ANSYS. According to the results of the simulations an optimized pressure die is manufactured. Several experimental tests are accomplished to verify the effect of the optimized tool design. Approximately 100 bends confirm a decrease of ovality using modified pressure die.
Influence of geometry bending areas on the durability of tubular stabilizer bars
Kužela, Josef ; Lidmila, Zdeněk (referee) ; Peterková, Eva (advisor)
Diploma thesis discusses and summarizes the problematic how ovality effects durability of bended tubes. The work presents an approach to the solution, the experiments concerning change of ovality, changes in the thickness of the distorted cross-section. Final results represent connection between ovality and durability.

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