Technical Transactions. Iss. 11

Technical Transactions. Iss. 11

Type: Collection of magazine numbers
Release date

Collection items (17)


Air consumption survey for pneumatic cushion in different nozzle configurations during moving loads

Kwiatkowski, Dominik
Article
2018
The subject of this paper concerns the search for structural solutions of pneumatic cushions [1, 2] in order to minimize the air consumption, operate at the lowest admissible pressure and compensate for the unevenness of the floor. The paper presents the solution with a multi-nozzle air outflow. This solution was obtained by a theoretical analysis, then a prototype of the device was made and laboratory tests were carried out.

Assessment of mechanical properties of PA 3200 GF polyamide models made by SLS

Kundera, Czesław, Kozior, Tomasz
Article
2018
The paper presents the results of mechanical properties research of samples made in the Selective Laser Sintering technology. Polyamide powder PA 3200 GF reinforced with glass fiber was the material used to build the model. Samples subjected to a uniaxial tensile test were made in accordance with ASTM D638 – V standard. The printing direction was the technological parameter of the study. The analysis of the results showed that the addition of fiberglass significantly influenced the improvement of mechanical properties, especially the isotropic of mechanical properties with respect to the printing direction.

Assessment of the quality of epoxy coating in the automotive industry

Dudek, Agata, Lisiecka, Barbara, Strzelczak, Katarzyna
Article
2018
Increasingly, many conventional and advanced automotive coatings applications demand materials with well-defined surface properties, fulfilling specific requirements and affecting automotive industrial development. The main assumption for the study was to analyze the microstructure and adhesion of epoxy powder coating on a steel substrate. The results of optical microscope metallographic, SEM/EDX, XRD analysis and adhesion test are presented.

Sensorless step positioning of hydraulic linear actuator

Dindorf, Ryszard, Woś, Piotr
Article
2018
The paper presents a design, working principle and simulation of a sensorless position system whose hydraulic linear stepper actuator is controlled by a combination of single binary on/off valves. For dynamic modelling and digital simulation of stepper actuator, the bond graph method was used. Preliminary simulation tests were conducted to determine the dynamic characteristics and dynamic properties of the stepper actuator.

Analysis of the crack width of beams reinforced with FRP bars

Brózda, Kinga, Selejdak, Jacek, Koteš, Peter
Article
2018
The paper investigates and compares a selected issue of Serviceability Limit State (SLS) of simply supported reinforced concrete (RC) beams subjected to various values of flexural stresses. Characteristic crack widths of beams reinforced with various types of bars were calculated. Beams reinforced with Glass Fiber Reinforced Polymer (GFRP), Carbon Fiber Reinforced Polymer (CFRP) and Aramid Fiber Reinforced Polymer (AFRP) were examined. The computational analysis of beams reinforced with FRP bars was based on Italian guideline for the design (CNR-DT 203/2006) and in accordance with the EC2 (EN 1992-11:2004). Based on the conducted analysis, the effect of changing the service live load on the increase in crack width was presented.

The impact of the shape of screen openings on groundwater flow to a deep drilled well

Wilk, Barbara K., Urbański, Aleksander J.
Article
2018
The authors propose a supplementary method for modelling seepage flow around a deep drilled well screen. The study applies 3D numerical modelling (FEM) in order to provide an in-depth analysis of the seepage process. The analysis of flow parameters (flux distribution q(x, t) and pressure distribution p) was conducted using the ZSoil.PC software system. The analysis indicates that the shape of perforation is of secondary importance during deep bore well screen selection.

The range of load variability of rectifier units with a concentrated disposition of tram substations as exemplified by a real tram line

Oćwieja, Dominik, Markowski, Paweł, Prusak, Janusz, Woszczyna, Bartosz
Article
2018
The first part of this paper presents a comparison of the measured and simulated results of the load variability of rectifier units of a tram traction substation. The subject of the tests was a power supply substation for the contact line of a tramway, the profile and traffic of which was known. After a positive appraisal of the applied simulation method, an assessment of the range of load variability for the rectifier units took place for a hypothetical situation involving the concentrated disposition (layout) of the traction substations (socalled micro-substations). The results acquired under the described circumstances are presented in the second part of this paper.

The efficiency of using artificial feedforward neural networks with a single hidden layer of eight neurons for the analysis of overload conditions of selected tramway traction substations

Dudzik, Marek, Prusak, Janusz, Drapik, Sławomir, Kuznetsov, Valeriy
Article
2018
This paper presents further results of research on the load variability of rectifier units for the selected tram traction substation. Actual measurements were used in the performed analysis. This time, the analysis was focused on the characteristics of maximum loads and overloads for time periods of five minutes and sixty minutes, for a number of selected cases. The second part of the article discusses the effectiveness of the use of artificial neural networks of the feedforward type with one hidden layer with eight neurons to analyse the overloads of the traction substation over a longer time scale. The obtained positive results indicate that this type of research should be continued, using different variants of artificial neural networks.

Measurement and simulation testing of harmonics in the on-board power grid of traction vehicles

Czuchra, Wojciech, Woszczyna, Bartosz
Article
2018
The requirements relating to the emission of auxiliary AC supply sockets in traction vehicles have been extended in standard PN-EN 50121-3-2:2015 by voltage harmonics measurement. This applies to the public on-board AC supply grid which is accessible to all passengers. It is concerned with providing the quality of power supply which is required by computer devices and mobile phone rechargers. This article presents the requirements and test methods resulting from extended standard scope. Normative factors, for which levels of permissible voltage harmonics in the public supply grid of traction vehicle have been defined are discussed. Examples of comparative results obtained from measurements and analyses of voltage harmonics within on-board supply grids are also presented. The presented results include extended calculations of distortion factors for groups and subgroups of supply voltage harmonics. In order to improve the quality of voltage within the on-board grid, which did not meet the requirements, simulation calculations were performed and an additional output sinusoidal filter was proposed.

The fire resistance of steel plate girders with slender webs – a comparative study

Woźniczka, Piotr, Piekarczyk, Marek
Article
2018
A comparative study of the load-bearing capacity of selected steel plate girders with slender webs under fire action is presented in this paper. Typical plate girders and girders with corrugated webs are considered. Stiffeners are only placed at the ends of cantilever beams so the shear buckling is a possibility. Fire resistance of the analysed members was estimated using two separate FEM software packages. Moreover, the computational approach applied for each case was different, thus validation of the software was possible. Failure modes, critical temperatures and deformations for steel plate girders subject to fire temperatures are also presented.