Showing papers by "Ternopil Ivan Pul'uj National Technical University published in 2017"

Algorithm for the assessment of heavyweight and oversize cargo transportation routes

Abstract: The improvement of transportation systems and technologic equipment leads to changing technical capabilities of this equipment. With the development of technologies, industrial development is also inevitable, resulting in correspondingly increasing need of transportation of HeavyWeight and OverSize (HW/OS) cargo. The application of a systematic approach in HW/OS cargo transportation processes allows reducing costs of delivery of such a cargo several times, which leads to a dramatic change of economic development and investment attraction conditions. Thus creating a system of criteria for the selection and assessment of HW/OS routes, which would allow selecting the most appropriate route of transportation in terms of cost and time, is expedient for this reason. The algorithm for the assessment of HW/OS cargo transportation routes will be drawn up in this article. This algorithm enables an objective evaluation of HW/OS transportation processes comparing different modes of transport, route segments, cargo transportation and cargo handling technology, and it can be practically applied to any territory.

Enhancing plasticity of high-strength titanium alloys VT 22 under impact-oscillatory loading

Abstract: The purpose of this paper is to provide new experimental data for high-strength VT 22 titanium α + β-type alloy under impact-oscillatory loading and dynamic non-equilibrium process. Based on the performed experimental studies, it was found that overall plastic deformation of this alloy can be increased by a factor 2.75 compared with its initial state without significant loss of strength. To achieve this goal, a new methodology to study the impact behaviour of materials under non-equilibrium process has been used. Physical research revealed that significant microstructural refinement of the alloy is observed after such type of loading, as the result of which the fine grains are formed with subgrain refinement which takes place within the basis of alloy.

Energy efficiency analysis of the manipulation process by the industrial objects with the use of Bernoulli gripping devices

Abstract: Abstract The article deals with the topical issue of reducing energy consumption for transportation of industrial objects. The energy efficiency of the process of objects manipulation with the use of the orientation optimization method while gripping with the help of different methods has been studied. The analysis of the influence of the constituent parts of inertial forces, that affect the object of manipulation, on the necessary force characteristics and energy consumption of Bernoulli gripping device has been proposed. The economic efficiency of the use of the optimal orientation of Bernoulli gripping device while transporting the object of manipulation in comparison to the transportation without re-orientation has been proved.

The role of notch tip shape and radius on deformation mechanisms of 12Cr1MoV steel under impact loading. Part 1. Energy parameters of fracture

Abstract: Impact loading curves and fracture energy of the notched 12Cr1MoV ductile steel specimens are analysed. The qualitative description and quantitative parameters are obtained for major stages of ductile and brittle fracture depending on the shape of the notch and the stress stiffness ahead. It was shown that a zone with enhanced plasticity forms in the vicinity of V-, U- and I-shaped notches at 20 °C testing temperature, giving rise to ductile fracture. The stress stiffness at the notch tip increased with testing temperature reduced to −40 °C. We demonstrated that the size of shear lips on a fracture surface is a quantitative characteristic of fracture. Using this approach, which is close by nature to non-linear fracture mechanics, together with the quantitative description of fracture surfaces, a physical–mechanical scheme of the specimen fracture was suggested for the case of enhanced and localized (constrained) plasticity near the stress concentrator tip.

Assessment of Potential Environmental Risks from Saline Soils Subsidence

Abstract: The nature and causes of soil subsidence in the areas of liquidated mining and chemical companies of the Carpathians are analyzed. Based on calculation results, was obtained dependences of salts concentration in the liquid, and the specific content of salt through the thickness of soil over time in cases of the dispersed and film salinity.

Influence of dynamic non-equilibrium processes on strength and plasticity of materials of transportation systems

Abstract: New experimental results on the effect of additional force impulse loading on the variation of the initial structure of the aircraft material (alloys D16, 2024-T3, VT22) at various stages of deformation are presented and a significant enhancement of its initial plasticity is achieved. Complex investigations into the material properties after a dynamic non-equilibrium process made it possible to describe the main regularities in the nature of deformation and fracture of materials, which allowed proposing general recommendations on using the revealed physical and mechanical regularities in the evaluation of strength of aircraft structures.

A feasibility study of using composite reinforcement in transport and power industry structures

Abstract: About 92% of Lithuanian bridges are made of reinforced concrete. Therefore, the problem of increasing the reliability and service life of their structures is most important for ensuring effective operation of transport buildings. The main factor causing transport building structures’ failure is associated with high water permeability and low resistance to attack by corrosive media of concrete used in construction. Ports, bridges, tunnels, viaducts make a group of transport structures strongly attacked by the aggressive media, e.g. cold air, water, ice, salts, etc. Though the members of these structures (e.g. columns, beams) are usually designed for 50 years of service, they often require a major overhaul or strengthening, when less than the half of this period has passed. Most of the damaged structures are the destroyed protective concrete layer and the corroded steel reinforcement. The corrosion of steel reinforcement is the main problem, causing the decrease of strength in the structures’ and th...

Development of family leisure activities in the hotel and restaurant businesses: Psychological and pedagogical aspects of animation activity

Abstract: The development of family leisure activities in the hotel and restaurant businesses with consideration of psychological and pedagogical aspects of animation activity is an actual task facing modern managers. The purpose of the study is to substantiate the relevance and identify the psychological and pedagogical aspects for designing a program of leisure activities in animation service. The challenge is to substantiate the need for a psychological and pedagogical approach to the work of a manager who develops and performs animation activities in the hospitality industry, as well as to show the impact of the animation service on the quality of service. The factors influencing the formation of animation services are analysed in the article; the main functions and trends of animation activity are highlighted; the ways of introducing animation programs into the domestic tourism activity are identified. The tourism industry development in the general infrastructure of the hospitality industry will help solve various problems: upbringing, culture developing, strength-recreating, mood raising, creating a unique recreation program to attract more guests.

The role of notch tip shape and radius on deformation mechanisms of 12Cr1MoV steel under impact loading. Part 2. Influence of strain localization on fracture and numeric simulations

Abstract: The fracture energy of 12Cr1MoV steel specimen with V-shaped, U-shaped and I-shaped notches under impact loading was measured and analysed. The results were described using three common approaches to ductile-brittle fracture: force-based, energy-based and strain-based. Within the stage-wise approach of physical mesomechanics of materials, the rate of increase/decrease of load at the stage of initiation and propagation of a macroscopic defect was evaluated, providing a good correlation with the work of fracture. The excitable cellular automata technique was applied to simulate the deformational behaviour of the specimens with different shape of notches. It was demonstrated that in the case of the blunted notch, the maximum impact toughness is facilitated by a more uniform distribution of the load along the notch, which hinders brittle fracture at lower testing temperature. For the specimen with the sharp I-notch, the bands of localised shear are oriented normally to the loading axis, inhibiting macroscopic localisation of strain and crack propagation. For this reason, the impact toughness of the specimen with the I-notch appeared to be higher than that of the V-notched one. Using the fractographic analysis and the size of shear lips as a quantitative fracture parameter, a physical-mechanistic scheme of fracture was suggested for the case of enhanced localised plasticity near the stress riser.

Improvement of the organizational-economic mechanism of resource-saving at the machine building enterprise

Abstract: The characteristic of the resource-saving at the machine-building enterprise has been presented. The complexity and system of the resource-saving control, as well as reasonableness of the development of the efficient organizational economic resource-saving mechanism have been interpreted. It was testified that the basis of the successful activity strategy in the resource-saving at the local machine-building enterprises is the efficient application of the available resources according to the requirement of the manufacturing products. Efficiency of such control can result from the proper application of the resourcenomy levers as a new science. Innovation chain of investigation of the resource-saving control problems from the point of view of resourcenomy has been proposed. Determination of the most efficient ways of setting up the organizational economic mechanism of resource-saving basing on the qualitative and quantitative factors of the resources application, using the resourcenomy techniques and taking into account the possibility to provide the enterprise with technologies, staff, control system, as well as the influence of each of the factors of the outside and inside environment of the enterprise, has been presented.

The impact of selected technological and material parameters on the strength of adhesive steel sheets joints

Abstract: The following paper analyses selected problems regarding the impact of technological parameters and the type of adherend material on the strength of adhesive-bonded steel sheet joints. The subject of the test was a single-lap adhesive joint of S235JR steel sheet. Joints were formed on two types of substrates: with or without corrosion products on the surface. The surface of steel sheet adherends was pre-treated with three cleaning solutions: acetone, Wiko industrial degreasing agent and Cortanin F anti-corrosion agent, depending on the state of the surface. Adhesive joints were formed with Epidian 53/ET/100:15 epoxy adhesive. The formed joints were subjected to one of three ageing variants: 14 days, two months and 3 months, which were followed by destructive testing to determine the shear strength of joints. The analysis of results obtained in the tests indicates that the strength performance of adhesive joints of corrosion-free adherends was characterised by higher values than in corroded steel sheets, regardless of ageing time.

Adhesive properties and adhesive joints strength of graphite/epoxy composites

Abstract: The article presents the results of experimental research of the adhesive joints strength of graphite/epoxy composites and the results of the surface free energy of the composite surfaces Two types of graphite/epoxy composites with different thickness were tested which are used to aircraft structure The single-lap adhesive joints of epoxy composites were considered Adhesive properties were described by surface free energy Owens-Wendt method was used to determine surface free energy The epoxy two-component adhesive was used to preparing the adhesive joints Zwick/Roell 100 strength device were used to determination the shear strength of adhesive joints of epoxy composites The strength test results showed that the highest value was obtained for adhesive joints of graphite-epoxy composite of smaller material thickness (048 mm) Statistical analysis of the results obtained, the study showed statistically significant differences between the values of the strength of the confidence level of 095 The statistical analysis of the results also showed that there are no statistical significant differences in average values of surface free energy (095 confidence level) It was noted that in each of the results the dispersion component of surface free energy was much greater than polar component of surface free energy

Impact of AC Current Density on Material Corrosion of Distribution Pipelines

Abstract: Abstract Vliv střídavého indukovaného proudu na korozní rychlost oceli St3 a 17GS byl pozorován v simulovaných půdních elektrolytech typických pro Ukrajinu. Ocel St3 je citlivější na přirozené korozní napadení v půdě i na napadení vyvolané střídavým proudem. Byla stanovena nejhorší prostředí z hlediska koroze v elektrolytech obsahujících chloridy či směs chloridů se sírany.

Research of the structure and trends in the development of the logistics market in Ukraine

Abstract: The purpose of the article is to study the structure and capacity of the Ukrainian logistics market. Based on the use of statistical methods, mathematical modeling, forecasting, the main development trends of the market of logistics services in Ukraine are determined. The research results can be used both in scientific sphere and for making investment decisions in the practice of players of the Ukrainian market.

Micromechanisms of ferrite-pearlite steels fracture under cyclic and impact loading

Abstract: During operation, the railway axle is exposed to static, cyclic and dynamic loading that is accompanied by influence of corrosive environments. This causes the accumulation of structural and mechanical damages in the material, formation of corrosion and mechanical micro-defects that are potential sites of fatigue crack nucleation and growth. This requires the development of failure analysis methods that allow determining main mechanisms of ferrite-pearlite steels fracture on the micro scale level. The railway axle’s material – the OSL steel – main regularities of temperature influence on fracture mechanisms in ferrite-pearlite steel type are shown. Qualitative and quantitative analysis of fracture surface of Charpy specimens tested at 20°C and -40°C was performed on micro scale level using SEM investigation.

Analysis of inner surface roughness parameters of load-carrying and support elements of mechanical systems (research note)

Abstract: Physical and mechanical regularities in the effect of certain processing operations on the shape and roughness of the hydraulic cylinder surface are found. The mechanisms of the spatial self-organization of the relief and surface of bearings under conditions of false brinelling are summarized and analyzed. The data obtained can be used for further scientific generalization or prediction and diagnostics of the surface condition of load-carrying and support elements of mechanical systems under study.

The impact of the kinematic parameters of bounce and pitch motions of sprung mass on wheeled vehicles handling

Abstract: The impact of the kinematic parameters of bounce and pitch motions of wheeled vehicles’ (WVs’) sprung mass (SM) with non-linear power characteristics of the cushion system on vehicles handling is studied The dependence of the critical value of the dynamic steering angle of directive wheels on the amplitude of bounce and pitch motions and the kinematic parameters of motion is developed It is proven that the limit value of the dynamic steering angle of directive wheels is reduced during acceleration, and vice versa (it increases during braking, while the bounce and pitch motions are significantly reduced)

Reasons for crack nucleation in welded joints of main gas-pipelines after a long-term operation

Abstract: A crack of operational origin in the welded joint of the main gas pipeline is analyzed. The reasons for its nucleation and impact on technological microdefects that were formed earlier during the welding are found. Micromechanisms and stages of nucleation and propagation of the crack are investigated.

Estimating mechanical state of AA2024 specimen under tension with the use of Lamb wave based ultrasonic technique

Abstract: Experimental results on application of ultrasonic technique utilizing Lamb waves for evaluation mechanical state of AA2024T3 specimens under tensile testing are presented. PZTs used as actuators an...

System identification of dynamics spread of microorganisms in dairy products based on pattern recognition

Abstract: Realization of automated reading and video processing to study efficient algorithms for tracking the dynamics of growth and spread of spores of mesophilic and thermophilic microorganisms were studied. The basic steps based on the algorithm of automatic counting and tracking spore colonies in real time were investigated.