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Asphalt Layers using Fibreglass Composite Materials
Sadil, Dominik ; Hýzl, Petr (referee) ; Šperka, Pavel (advisor)
The diploma thesis deals with using of reinforcing composite materials in asphalt layers. These geosynthetic materials are in road construction used especially to reduce spreading cracks and extend the service life of the construction. As par of this work, test specimens of different types of asphalt layers were produced. These samples were subjected to laboratory testing, where the results of different reinforced asphalt slabs were compared. Within the diploma thesis primarily deals with the testing of the shear bond strength between asphalt layers in order to determine what are the other influencing factors of the test. Another part of the thesis is the 4-point bending test, during which a special technology in the form of a DIC camera was used to monitor the behavior of the asphalt layer over time.
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Use of the DIC method in solving basic problems of solid mechanics
Hrůza, Vlastimil ; Pokorný, Jan (referee) ; Ščerba, Bořek (advisor)
This bachelor’s theses deals with the solution of basic problems of solid mechanics using digital image correlation. The research part of the thesis presents some of the optical methods used for deformation measurement, digital image correlation in particular, whose history, principles, limitations and utilizations are described in detail. In the practical part of the theses, three experiments are carried out, which are then evaluated using digital image correlation and the results are compared with the created computational models. In the first experiment, strain on the tensile test specimens with notches is measured, the second experiment is focused on measuring strain when bending curved beams and in the final experiment, natural frequency of a fork produced by 3D printing is determined.
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Determination of Material Properties of Specimens Produced by Metallic 3D Printing
Zakl, Alexandr ; Peterková, Eva (referee) ; Řiháček, Jan (advisor)
This bachelor's thesis deals with mechanical properties and current status of 3D printing of metal parts, especially by DMLS/SLM method. Research part is dedicated to various technologies and suppliers in the field of 3D printing with emphasis on printing metal methods. Main purpose of this thesis is to connect the worlds of 3D printing and 3D optical measuring of deformation, so the part of research segment is dedicated to optical measuring and leading innovative company GOM. One of the leading product of this company is ARAMIS and in the context of this thesis it was present during the experiment as a instrument for measuring and inspecting material characteristics, and is present in research part where is mentioned a principle on which this device is working (digital image correlation) as is the device itsself. In the experimental part of this thesis, samples were printed on DMLS printer from company XactMetal, which were then submitted to a tensile test. Measurement was done using DIC based device ARAMIS and inspected for basic material properties in same named program.
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Comparison of strains determined by finite element method and by optical measurement system
Zajíček, Vít ; Hlavoň, Pavel (referee) ; Vlk, Miloš (advisor)
This thesis focuses on the comparison of numerical simulation and optical measurement of deformation of the turbinehousing made by Honeywell company. The numerical calculation performed by finite element method to simulate transient thermal load on the measured entity. Numerical result of the strain state of the body caused by temperature gradients. To verify the simulation is used an experimental digital correlation method VIC-3D. The thesis also mentioned the theoretical foundations of digital correlation methods and thermal analysis.
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Computational analysis of a car axle arm opening
Procházka, Vojtěch ; Kubík, Petr (referee) ; Petruška, Jindřich (advisor)
This thesis is focused on behavior of control arm opening with bushing pressed in. The tested component is a part of control arm of a car. The parts were tested in tensile and compressive strength. Real experiments were measured by optical system Aramis during the testing to determine deformations of the part. These tests are also modeled by a finite element method using an Abaqus software. In GOM Correlate software is created full-field comparison of deformation results from Aramis and FEA. Based on this comparison computational model is calibrated. Sensitivity analysis is performed at the end of the thesis.
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Optical measurement of crack length utilizing the DIC method
Dziubek, Jan ; Halabuk, Dávid (referee) ; Ščerba, Bořek (advisor)
The thesis deals with the measurement of crack length using digital image correlation. The theoretical part of the thesis presents the method of digital image correlation, crack problems, and also introduces conventional methods for measuring crack length. There are currently no universal procedures in the field of crack length measurement using DIC. Different authors have only proposed different procedures to find the crack tip. Three different methods are used to determine the crack length using digital image correlation. Use of the edge detection method in the displacement field, the inflection point search method and the deformation threshold method. The aim of this work is to describe and compare these approaches.
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ANALYSIS OF MIXED MODE I/II FAILURE OF SELECTED STRUCTURAL CONCRETE GRADES
Miarka, Petr ; Šejnoha,, Michal (referee) ; Hutař,, Pavel (referee) ; Seitl, Stanislav (advisor)
The presented thesis is devoted to the experimental and numerical analysis of concrete fracture under the mixed-mode I/II load. This phenomenon was analysed on various concrete grades and types which are used in the fabrication of precast concrete structural elements. Subsequently, the Brazilian disc test with central specimen was used in experimental and numerical parts. The numerical part employs both linear elastic fracture mechanics (LEFM) approach and non-linear material model to assess the concrete fracture and failure under the mixed mode I/II load. The LEFM part is dedicated to evaluation the geometry functions and higher order terms of the Williams’ expansion, while the non-linear analysis is dedicated to crack initiation and propagation throughout the specimen using the concrete damage plasticity model. The experimental part is dedicated to the analysis of the mixed mode-mode I/II fracture resistance by the generalised tangential stress (GMTS) criterion with focus set on the governing role of the critical distance rC. Furthermore, the experimental part validates the applicability of the Williams’ expansion on the concrete. For this, experimentally measured displacements by digital image correlation technique were used to calculate the Williams’s expansion terms. Lastly, the thesis deals with the influence of the aggressive environment on the material’s fracture toughness and on the fracture resistance under the mixed mode I/II has been studied.
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Application of DIC method for measurement of deformations on small specimens
Vejchoda, Ondřej ; Houfek, Lubomír (referee) ; Návrat, Tomáš (advisor)
This diploma thesis tries to find the most suitable optical system for measuring deformation displacements on the surfaces of bodies. The first chapter describes the systems and methods that will be used. The second chapter is devoted to the design of the experiment. It describes the preparation of the experiment from the point of view of software and hardware and what are the important preliminary preparations. The last chapter contains the results of experiments and evaluation of the systems.
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Application of DIC method in residual stress measurement using hole drilling method
Kováříková, Sabina ; Kubík, Petr (referee) ; Návrat, Tomáš (advisor)
This thesis deals with measurement of residual stress by hole drilling method. This method is based on drilling a hole and measurement of deformation in the area around this hole. Measured deformations are then converted to residual stresses by using calibration coefficients. The deformation around the drilled hole is measured by optical non contact method called digital image correlation (DIC). First part of the thesis is focused on current state of research. The thesis contains evaluation of residual stresses by using different methods and evaluation of used methods.
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