Jana Knedlova

Materials, construction and manufacture of the vehicle for inspection of piping systems

The article focuses on the design, construction and manufacture of an inspection vehicle intended to access difficult-to-reach places. The vehicle is able to monitor piping system failures at the view angle of 180° in deep depths and adverse environments. The individual components of the inspection vehicle, more detailed their programming and production on CNC machines are discussed. The vehicle is supposed to easily run into the piping systems and can be safely pulled out. A control system was created for motion and video signal transmission to the operator from above the ground. Aluminum alloy (EN AW 2024) is the predominant material of the manufactured components and at the same time has ideal processing and operating properties. Proposed inspection vehicle is a robust and functional solution with minimal maintenance.

Application of Theory of Hypothesis Testing in Process of Laser Micromachining

The article focuses on the field of PMMA laser micromachining at change of the technological parameters. The aim was to evaluate machined surface roughness at different setting of DPI definition (number of dots – paths on square inch). The aim is application of the Theory of Hypothesis testing for evaluation changing of final surface during imputing variable technological parameters.

Evaluation of DPI Change Impact on Laser Machined Surface Quality

The article focuses on the field of PMMA laser micromachining at change of the technological parameters. The aim was to evaluate machined surface roughness at different setting of DPI definition (number of dots paths on square inch). Commercial CO2 laser Mercury L-30 by firm LaserPro, USA was used for experimental machining. Ray of laser could be focused on mark diameter d=185 mm.

Application of Fractal Geometry for Laser Engraving of Artificial Leather Surface

The article deals with application of fractal geometry on a surface of polymeric material (artificial leather) obtained by laser micromachining. There was done an experimental manufacturing of the chosen entities at the change of a technological parameters and laser beam mode. The aim was to consider possible changes of the given surfaces resulting from different laser beam mode (pulse vs. continuous).

Scanning and Evaluation of Biological Surfaces Using the Technique of Rapid Prototyping

One of the most important characteristics of a cosmetic product is maintain or improving the condition and characteristics of the skin surface. In dermatological, respectively cosmetic practice, there is very often a problem of an objective assessment of the obtained data, which corresponds to visual changes in skin relief. With technical advancements has it been proposed many approaches of solution: mechanical needle devices, optical interference devices, and microscopic, holographic, laser and photometers ones. Each of them has its advantages and negative qualities. The newest devices allow not only two-dimensional assessment (2D), but also spatial one (3D). Scientific literature such as Measuring the Skin recommends for these cases scanning the surface in 3D, using the contact scanners for made imprints. Here, however, errors that may be caused by mechanical method of scanning skin relief are not taken into consideration and there is also not clearly described the material suitable for the production of custom impression. The following article focuses precisely on this issue, specifically on the implementation of the biological surface relief imprint using a silicone impression material, its 3D scanning without contact and forming an enlarged replica by rapid prototyping technology.

Use of Relocation Device at Scanning of Polymeric Material Surface Quality

Nowadays, manufacturers and users of parts made of polymeric materials make increasing demands on surface quality of these parts. In order to fulfill these claims, it is necessary to use not only the quality measurement systems for surface quality inspection, but also suitable products that allow to set up the inspected polymeric component properly set up to the measuring system scanner. However, it is not sufficient. Due to the requirements of the customers or the production it is often necessary to repeat the surface quality measurement, which is more and more often done in 3D; that might be quite difficult. Except for special cases there should not be any marks done by the inspection workplace which might lower the inspected surface quality. Therefore it is not suitable to make mechanical marks such as scratch, ridge, etc. On the other hand, other types of marks done by non-invasive method, such as sticking paper marks, measuring cross, etc. is also not admissible as there might result in surface damage due to adhesive forces as well by mechanical or chemical processes. Thus it is necessary to take into account the fact that parts made of polymeric material can be so small that none of the above mentioned methods that are widely used nowadays cannot be applied just because of the dimensional reason.

Laser Micro-Machining and Temperature Field Simulation

The parametric thermal field analyses were realized by the finite element method. The analysis was run in the software solver COSMOS/DesignSTAR thermal. The thermal module makes possible to realize cases of the thermal dependences on the material properties. Material data can be entered as a function of the temperature. The thermal and physical characteristic of the polymeric materials are changed very expressively. The output of the analysis was temperature distribution described by various colors and assigned values in the spectrogram.

An Approach for Residual Stress Determination by Mechanical Indentation Technique

Abstract Residual stresses lower the utility value of plastic parts. Determination of the induced stresses can help deal with them. Measurements are time-consuming and expensive. A new approach to measuring residual stresses, such as indentation measurement, can lead to the simple determination of residual stresses. The paper shows the relationship between the condition of injection moulding, the subsequent residual stress, and hardness through thickness. The computer model displays the field and magnitude of residual stress in the samples. The model results are then compared to measured parameters after indentation and the magnitude of residual stress determined by the standard hole drilling method.