MM Science Journal, November 2020

November 2020

EFFECTS OF PRESSURE IN CONTINUOUS DRIVE FRICTION WELDING ON AISI 304 AND A36

Helmy Purwanto, Muhammad Dzulfikar, Imam Syafaat, Sohabat Imanu, Nur Kholis
Keywords: Friction welding | forging pressure | friction characteristics | strength of friction welding joint

Friction welding is a connection by frictional heating due to the rotation of one metal against another metal under the influence of axial compression. This study aims to determine and analyse the effect of pressure on the shape of the welded connection, microstructure, tensile strength and hardness in Continuous Drive Friction Welding (CFDW). The materials used were AISI 304 and A 36 carbon structural (…)

DEFORMATION CHARACTERISTICS OF AUTOMOBILE IN A FRONTAL IMPACT INTO RIGID BARRIER

Jozef Kmec, Jozef Pavelka, Jaroslav Soltes
Keywords: EES. | Deformation work | Deformation characteristics

Current simulation programmes for analyzing car accidents uses impact velocity, mass, user-defined overlay and a coefficient of restitution for defining the value of EES (Energy Equivalent Speed). However, the impact velocity must be entered manually through the expert´s own calculation of EES parameter depending on the level of car damage. To do this, experts can choose from several available methods. (…)

MECHANICAL PROPERTIES OF TWO TYPES OF LATTICE STRUCTURES FABRICATED WITH THE USE OF HP MULTIJET FUSION TECHNOLOGY

Jiri Safka, Michal Ackermann, Martin Seidl, Filip Vele, Jakub Machacek, Lubos Behalek, Petr Henys, Jacqueline Pereira Rocha, Veronika Truxova
Keywords: lattice structures | mechanical properties

Research in lattice structures and its application belongs to one of the most emerging disciplines in development of new types of engineering materials. High strength-to-weight ratio, special damping capabilities or auxetic behaviour are just a set of properties which can be directly influenced during design of these materials. Due to the geometric complexity of these structures, additive manufacturing (…)

VIBRATION FATIGUE - FEM ANALYSIS VS. REAL TESTING

Karel Raz, Miloslav Kepka, Julie Volkmannova
Keywords: testing | FEM | steel | fatigue | vibration

Main aim of this article is to present results of the basic research in the area of the fatigue of material. The work was focused on the improvement of the computational support (for the FEM approach) for the material fatigue evaluation. Tested parts were exposed to vibrations and therefore was noticed higher risk of the failure caused by the vibration-fatigue. The real testing is described in this work (…)

FUZZY APPROACH OF MODELING A HYDRAULIC TURBINE EFFICIENCY

Richard Olexa, Daniela Perdukova, Pavol Fedor
Keywords: fuzzy model of turbine efficiency | small hydropower plant | modelling and controlling of hydropower plants | hydropower systems | hydraulic turbines

Research, optimization and practical implementation of a Small Hydropower Plants as a source of clean electricity are one of the actual tasks in the current energetics, which is virtually impossible to solve without powerful computer support due to the strongly nonlinear nature of such systems. The article presents an overview of the most common simulation model schemes of Small Hydropower Plants, where (…)

THE INFLUENCE OF ANNEALING TEMPERATURE ON TENSILE STRENGTH OF POLYLACTIC ACID

Jiri Suder, Zdenko Bobovsky, Zdenek Zeman, Jakub Mlotek, Michal Vocetka
Keywords: additive manufacturing | 3D Print | tensile strength | fused filament fabrication | Polylactic Acid | annealing

Polylactic acid is one of the most used materials in Additive Manufacturing technologies, especially in Fused Filament Fabrication. Although its tensile strength is relatively good in comparison with other materials in the same price category, it is possible to increase it after printing by annealing. One of the most important parameters for annealing is the annealing temperature. This article deals wit (…)

EFFECTS OF ADAPTIVE CONTROL OF THE DRILLING PROCESS

Karol Vasilko
Keywords: durability | cutting force | Machining Time | drilling | Machining

The paper analyses the drilling as the machining process with applied adaptive control. Experience with the use of NC machine tools shows that cutting conditions cannot be optimized without more detailed knowledge of the machining process. The numerical control of the machine tool gives more space to the technologist for creative control of the cutting process. The essence of the adaptive machining syst (…)

ABOUT WEAR RESISTANCE OF LINEAR BLOCK-POLYURETHANES

Volodymyr Mykolajovych Anisimov, Anton Panda, Volodymyr Volodymyrovych Anisimov, Konstantin Dyadyura, Iveta Pandova
Keywords: thermal diffusion surface saturation | counterbody roughness | content of rigid blocks | molecular weight | Hardness | coefficient of friction | wear resistance | linear block-polyurethane

Linear block-polyurethanes (BPU) are finding more and more practical applications in industry, and their recipe range is rapidly expanding. It is shown that the evaluation of the tribotechnical characteristics of BPU depending on hardness, as suggested by ISO 16365-1:2014 P1, is inaccurate and requires further research to establish the relationship between structure and properties of polyurethanes, taki (…)

THROUGH TRANSMISSION LASER WELDING PROCESS OPTIMIZATION FOR SEMICRYSTALLINE AND AMORPHOUS PLASTICS

Martin Seidl, Jiri Safka, Lubos Behalek, Iva Novakova
Keywords: tempering | mold material | temperature distribution | HPDC

The paper is focused on the research in welding of plastic materials PP, PA 6.6 a ABS. This study deals with the optimization of individual parameters of the transmission laser welding process. The welds’ quality evaluation was based on the testing of thermal and mechanical properties. The plastic materials were modified using the colouring pigments, nucleation agents and glass fibres.

TUNING PERCEPTION AND MOTION PLANNING PARAMETERS FOR MOVEIT! FRAMEWORK

Stefan Grushko, Ales Vysocky, Vyomkesh Kumar Jha, Robert Pastor, Erik Prada, Lubica Mikova, Zdenko Bobovsky
Keywords: optimization | tuning | manipulators | benchmark testing | MoveIt | perception | Motion planning

This paper performs a benchmark of main parameters of perception and planning available in MoveIt! motion planning framework in order to identify parameters the most affecting the overall performance of the system. The initial benchmark is performed on a virtual simulation of UR3 robot workspace with a single obstacle. The performance is measured by means of successful runs, path planning and execution (…)

ON LOCAL WIRELESS REMOTE CONTROL

Alena Galajdova, Robert Rakay
Keywords: microcontroller | micro system | wireless communication | Remote control

The article deals with the design of a home automation system. The proposed system combines wireless data transmission and positioning device. The main components and their parameters, which are necessary for building such system and base steps how to create and test a device are described. The created system can serve as a suitable basis for a truly deployed system with minor changes, as the tested dr (…)

WELDING METHODS OF FILAMENTS USED IN FFF/FDM 3D PRINTING TECHNOLOGY

Anton Panda, Samuel Cehelsky
Keywords: FFF | FDM | PLA | ABS | filament | 3D printing

The paper discusses methods of welding or joining of two separate filaments for FFF/FDM Technology of 3D printing. Article also concerns advantages and disadvantages of mentioned methods. Various materials used in this printing technology are described, their welding capability and physical properties such as working temperatures and their suitability. The article describes various devices and prototype (…)

PROPERTIES AND CRYSTALLIZATION OF PLLA BIOPOLYMERS WITH CELLULOSE NANOCRYSTALS AND ORGANIC PLASTICIZER

Martin Boruvka, Lubos Behalek, Jan Novak
Keywords: acetyl tributyl citrate | cellulose nanocrystals | Poly(lactic acid)

The paper deals with the research of ternary nanocomposites based on PLLA nucleated by lignin coated cellulose nanocrystals (L-CNC) and simultaneously modified with an acetyl tributyl citrate (ATBC) plasticizer. The potential synergistic effect of both additives on the crystallization and morphology of nanocomposites is evaluated by differential scanning calorimetry (DSC) and scanning electronic microsc (…)

MULTIDIMENSIONAL DESIGN OF TECHNOLOGY FOR OBTAINING SOLID LUBRICANT COATING ON TOOL HARD ALLOY

Alexander Shmatov, Lubomir Soos, Zdenko Krajny
Keywords: hard alloy | tool | solid lubricant coating | Thermo-hydrochemical treatment

This article deals with the new method for producing solid lubricant coatings on hard alloy tools by thermo-hydrochemical treatment (THCT). The results of investigation of the tribotechnical properties of solid lubricant coatings obtained on hard alloy ВК6 grade (94 % WC + 6 % Co) using THCT method are presented. The composition of the medium and the temperature and the time parameters of THCT process w (…)

APPLICATION OF NEW RULES FOR PATTERN SPECIFICATION ACCORDING ISO GPS

Karel Petr
Keywords: . | drawing descriptions | simultaneous requirement | geometrical tolerancing | constraint | tolerance zone pattern | GPS | pattern specification

This article is based on new rules used in ISO GPS standards (year 2017). All rules important for creating of tolerancing model (as dimension, roughness and geometrical specifications) was harmonized and more clearly defined across standards. Article provides rules for the tolerancing of a tolerance zone pattern, i.e. a collection of tolerance zones constrained to each other with or without reference to (…)

AERATION EQUIPMENT FOR BUBBLELESS AERATION WITH PARTIAL AUTONOMOUS REGIME FOR SMALL DEPTHS OF WATER COLUMN

Jan Sluse, Frantisek Pochyly
Keywords: cynobacteria | autonomous equipment | hollow fibre | diffusion | destratification | Aeration

Outbreak of cyanobacteria can cause problems with water quality in summer months. Cyanobacteria is a bacterium that produces poison called cyanotoxin. When the concentration of cyanobacteria increases, the phenomenon „algal bloom“ appears, which is very toxic and may kill all the organisms. The ecological reduction of growth of cyanobacteria is carried out by aeration of water. The mechanic and pneumati (…)

CONTROL OF RADIAL INCREMENT AND WINDING DENSITY OF COMPOSITE CYLINDRICAL SHELLS

Alex Kutin, Gennady Aryassov, Victor Musalimov, Trieu Minh Vu, Reza Moezzi, Jindrich Cyrus
Keywords: adaptive control | winding process control | thread tension | winding

There is an effective method of filament winding for the manufacture of hollow composite products (pipes, containers, etc.). Finished products are light, durable and widely used in industry. However, this method has significant drawbacks. The tension of the surface layer and the tension of the inner layers can differ significantly for the products being formed. This effect is also observed when the tens (…)

TRAINING AND PRACTICE TO ENSURE IMPLEMENTATION OF THE TPM SYSTEM

Libor Necas
Keywords: implementation | lecturer | practice | training | education | maintenance | Totally productive maintenance (TPM)

Applying the TPM system in practice is not only a technical and organisational matter. Equally significant and not to be overlooked is the process of education, training and practice (initial and continuous) for everyone who will be directly or indirectly engaged in the maintenance system based on TPM principles. Attention must be paid to the comprehensive and systematic provision of education in this a (…)

EVALUATION OF THERMAL CONDITIONS AT CAST-DIE CASTING MOLD INTERFACE

Jan Majernik, Stefan Gaspar, Martin Podaril, Tomas Coranic
Keywords: tempering | mold material | temperature distribution | HPDC

The internal structure of the castings depends on the super-cooling level of the melt upon contact with the face of the mold. In die casting technology, the relatively cold mold material comes into the contact with substantially higher temperature melt in short successive cycles. This causes high thermal fluctuations that cause cyclic thermal stress of the mold. The contribution evaluates the heat balan (…)

DETERMINATION OF STRESS AND DEFORMATION DURING LASER WELDING OF ALUMINIUM ALLOYS WITH THE PC SUPPORT

Jozef Mascenik, Slavko Pavlenko
Keywords: Simulation | deformation | stress | laser welding | Aluminium Alloys

The submitted paper deals with laser welding of aluminium alloys with the application of the computer support in the welding process. Currently, laser welding represents one of the most common processes as it allows accepting of high quality welds with minimal thermal zone in case of diverse materials such as steel, high-strength steel, aluminium or titanium. The use of computer support for the company (…)

MONITORING THE QUALITY OF THE SURFACE TREATMENT OF THE SELECTED COMPONENT DEPENDING ON ITS SHAPE COMPLEXITY

Emil Spisak, Gerhard Mital, Jan Varga, Tomas Jezny, Ivan Gajdos
Keywords: Measuring | corrosion | paint thickness | powder coating | monitoring

This publication deals with the issue of powder coating for the purpose monitoring the quality of the deposited layer depending on the complexity of the product and the type of material. Describes methods and materials used in different types of deposition of protective coatings. The work is carried out experiment, which expresses quality and thickness applying colour to the diagnosed sample and offerin (…)