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Probabilistic evaluation of the resistance to low-cycle deformation and failure of the critical components in the equipment used in the energy, engineering, metallurgy, chemical, shipbuilding, and other industries is of primary importance with the view towards their secure operation, in particular, given the high level of cyclic loading acting on the equipment during its operation. Until recently, systematic probabilistic evaluation has been generally applied to the results of statistical and fatigue investigations. Very few investigations applying this approach to the low-cycle domain. The present study aims to substantiate the use of probabilistic calculation in the low-cycle domain by systematic probabilistic evaluation of the diagrams of cyclic elastoplastic deformation and durability of the materials representing the major types of cyclic properties (hardening, softening, stabilization) and investigation of the correlation relationships between mechanical properties and cyclic deformation and failure parameters. The experimental methodology that includes the calculated design of the probabilistic fatigue curves is also developed and the curves are compared to the results of the experiment. Probabilistic values of mechanical characteristics were determined and calculated low-cycle fatigue curves corresponding to different failure probabilities, to assess them from the probabilistic perspective. A comparison of low-cycle fatigue curves has shown that the durability curves generated for some materials using analytical expressions are not accurate. According to the analysis of the relative values of experimental probabilities of low-cycle fatigue curves, the use of analytical expressions to build the curves can lead to a significant error. The results obtained allow for the revision of the load bearing capacity and life of the structural elements subjected to cyclic elastoplastic loading in view of the potential scattering of mechanical properties and resistance parameters to low-cycle deformation and failure. In addition, the results enable determination of the scatter tolerances, depending on the criticality of the part or structure. [ABSTRACT FROM AUTHOR]

This article presents an experimental–analytical statistical study of low-cycle fatigue to crack initiation and complete failure. The application of statistical and probability methods provides for the possibility of improving the characteristics related to the structural life and the justification for the respective values of cyclic loads in the design stage. Most studies investigating statistical descriptions of crack initiation or complete failure do not analyse the distribution of the characteristics, correlation relationships, and statistical parameters of low-cycle fatigue. Low-cycle failure may be quasistatic or (due to the fatigue) transient. Materials with contrasting cyclic properties were selected for the investigation: cyclically softening alloyed steel 15Cr2MoVA; cyclically stable structural steel C45; cyclically hardening aluminium alloy D16T1. All samples were produced in a single batch of each respective material to reduce the distribution of data. The lowest values of the variation coefficient of one of the key statistical indicators were obtained using the log-normal distribution, which is superior to the normal or Weibull distribution. Statistical analysis of the durability parameters showed that the distribution was smaller than the parameters of the distribution of the deformation diagram. The results obtained in the study enable the verification of durability and life of the structural elements of in-service facilities subjected to elastoplastic loading by assessing the distribution of characteristics of crack initiation and failure and low-cycle strain parameters as well as the permissible distribution limits. [ABSTRACT FROM AUTHOR]

The objective of this research is to propose new routing algorithms for the Storage and Retrieval Mechanism (SRM) in the Cylindrical Automated Storage and Retrieval System (C-AS/RS) and contribute to the system conceptualization by investigating the maximum achievable retrieval request rates for different routing algorithms and system parameters. For this purpose, flexible and detailed simulation model was developed and investigated for 2 SRM types, 3 routing algorithms and a feasible set of system movement and load transfer time parameters. Based on the simulation output, the regression models for different SRM types and routing algorithms were developed for predicting the maximum retrieval request rate. The differences of the average maximum retrieval request rate were evaluated for various system configurations and routing algorithms. The alternative to optimal routing algorithm was proposed, reducing the system performance only by 1.4 ÷ 2.4% on average, but requiring significantly less calculations when planning the SRM tour. In addition, the system analysis indicated that SRM vertical velocity and load transfer time have the highest impact on the system performance and for different SRM types the average maximum retrieval request rates differ by 22.2 ÷ 31.8%. [ABSTRACT FROM PUBLISHER]

The need for the means ensuring passive safety of a vehicle is becoming increasingly emphasized in the area of transport engineering. This area becomes particularly relevant when restoration of the damaged load bearing structures in vehicles is concerned. When performing restoration and modification of the vehicles according to specific needs or repairing them after traffic accidents, the lack of norms giving formalized determination of passive safety and recommendations for its assurance becomes obvious. Computational model of the roof structure developed in LSDYNA is presented, the weld intended for the structure joints is modelled, and residual stresses due to welding process are taken into account, the most effective model of weld location for A-pillar is selected and the influence of A-pillar on the strength of vehicle's roof structure is determined in case of quasi-static compression. [ABSTRACT FROM AUTHOR]

The objective of this research is to propose and investigate a new design of the Cylindrical Automated Storage and Retrieval System (C-AS/RS) and provide a performance comparison of the two types of Storage/Retrieval Mechanisms (SRM I and SRM II) for the system configurations with different input/output location numbers and positions. Although the better performance is expected from of the system with SRM II, because it contains the vertically independent moving load handling devices (LHDs) compared to the interconnected LHDs used in SRM I, the vertically independent movement requires more sophisticated equipment which should be considered by the system designers. Hence, the performance investigation is required to identify the differences between the two types of the SRMs for different C-AS/RS configurations. For this purpose, the detailed simulation model of the C-AS/RS was developed, investigated for various combinations of system parameters and the multiple regression models for predicting system performance measures were developed (adjusted R-square greater than 0.83 for all models). The differences of the performance measures were evaluated and showed that SRM II achieved 7÷20% higher load retrieval rates compared to SRM I for all investigated parameter combinations. The investigation also showed that the number and position of the input/output locations had a significant impact on the system performance. [ABSTRACT FROM AUTHOR]

This paper proposes the concept of a new type of Cylindrical Automated Storage and Retrieval system (C-AS/RS), which consists of the octagonal shape rack, system input/output (I/O) positions, load storage and retrieval mechanism (SRM), which rotates and moves simultaneously and contains a number of load handling devices (LHDs). Physical structure of the single and multi-LHD systems, control algorithms and the performance measures were presented. Simulation modelling techniques, descriptive statistics and analysis of variance were used in this research to identify the effects of different location of I/O positions, the number of LHDs on the SRM and the retrieval request rates to the performance of the C-AS/RS system. [ABSTRACT FROM AUTHOR]

This paper proposes the concept of a new type of Cylindrical Automated Storage and Retrieval system (C-AS/RS), which consists of the octagonal shape rack, system input/output (I/O) positions, load storage and retrieval mechanism (SRM), which rotates and moves simultaneously and contains a number of load handling devices (LHDs). Physical structure of the single and multi-LHD systems, control algorithms and the performance measures were presented. Simulation modelling techniques, descriptive statistics and analysis of variance were used in this research to identify the effects of different location of I/O positions, the number of LHDs on the SRM and the retrieval request rates to the performance of the C-AS/RS system. [ABSTRACT FROM AUTHOR]

Despite reduced resistance to wheel rim wear, after every grinding, only geometrical parameters of wheels are restored at maintenance depots. A tendency towards a decrease in the exploitation of wheel rim working edge induces the acquisition of new wheels, is related to a considerable increase in axle load and train speed as well as linked to the ineffective methods of repairing wheel rim working edge. A solution to the problem of restoring the surface of wheelset rolling, as a wider problem of rolling stock durability, is determined by the fact that the breakdown of the rolling wheelset and the loss of its efficiency shortens the service time of the wheelset. The cost of pointless and inefficient renovations of geometrical wheelset parameters increases and is of a very high rate. The problem of efficient renovations to rims and steel used for wheels within the maintenance of wheelsets becomes a burning issue today. [ABSTRACT FROM AUTHOR]

Abstract: In this article, diverse liquid biofuels of the first generation were compared as partial or infant substitutes for fossil diesel fuel applied in cogeneration plant of the average capacity of 340 kW. The study concentrates on agricultural and economic conditions as well as legislative basis distinctive to Lithuania. At the laboratory of the Lithuanian University of Agriculture Institute of Agro-Engineering an experimental diesel engine powered generator was fuelled with rapeseed oil methyl ester (pure and in the blend with fossil diesel and dyed diesel fuels) and rapeseed oil with excellent energy balances and emissions characteristics more favorable than fossil diesel. Detailed estimations were proposed in order to assess the economic feasibility of complementing renewable electricity and heat generated in the final output cycle. The carried out analysis showed, that good perspectives are forecasted for using diesel engines in cogeneration plants, if they run on rapeseed oil produced by farmers themselves. The operation of such a plant would realize 184960 € of annual income for sold electricity, allowing to pay annual depreciation expenses and exceed the production cost for thermal energy to be 0.033 €/kW h. This price lies under the established one by the centralized energy suppliers, accordingly 0.058 €/kW h. [ABSTRACT FROM AUTHOR]

Abstract: By the method of data collation, research into changes in life histories (ignition delay plus time of combustion) of the compounded fuel droplets (diesel fuel–biodiesel fuel (RME)–bioethanol), as well as diesel engine D-144 brake specific fuel consumption rates was performed and obtained results being compared to diesel fuel by an analogous manner. An optimum composition of the multi-component blend B30+7.5E demonstrating specific fuel consumption rates and droplet combustion characteristics very similar to diesel fuel was derived. In comparison to B30, a newly derived combustible blend demonstrated fairly improved emissions of exhaust gases. For low load mode: smoke opacity (−10%), NO X (−2%), CO (−20%), and HC (−12.5%). For average load mode: smoke opacity (−10%), NO X (−2%), CO (−22%), and HC (−14.5%). For high load mode: smoke opacity (−18%), NO X (−2%), CO (−22%), and HC (−18%). [Copyright &y& Elsevier]

Two fuel kinds of organic origin including rapeseed methyl ester (RME) and ethanol (E) were selected for their different physical-chemical parameters to study the maximum apt volume of oxygenates to mix fossil diesel (D) and establish expectancy to apply D-RME-E blend as a fuel for the unmodified high-speed diesel engine (a combustion chamber consists of a dished piston). The objective of the article is to provide an explicit relationship between the nature of fuel composition and diesel engine operating parameters. The results of the carried out tests on the engine oriented on dynamic and emission characteristics using various portions of the before mentioned bio-components in diesel fuel are presented. Engine behaviour seemed to be improved in the presence of ethanol additives in D-RME blend with a reduction in pollutant emissions in exhaust gases, fuel consumption, ameliorated cetane number, ignition delay time and physical-chemical characteristics of the investigated compounds. The positive and negative aspects of applying bio-based additives in fossil diesel are reported and discussed. [ABSTRACT FROM AUTHOR]

The functioning of international transport corridors is directly related to benefits in terms of personal mobility and economic activity. Transport is one of the main branches of economy without which the functioning of a modern economy is impossible in general. It ensures necessary economic links, joins all industrial units of a country into one whole thus establishing the conditions for economy to function coherently and efficiently. Thus, transport is an important branch of economy, however, its infrastructure expansion needs much investment. That is why investment projects for the development of the transport structure have to be thoroughly selected, and their implementation has to ensure sufficient efficiency not only economic but social terms - the indirect ones as well sometimes having even greater consequences on society than direct effects. Despite the fact that MCA as an instrument allows decision makers to include these criteria in so popular Cost -- benefit analysis, the research performed by the authors shows that the instrument in assessing social effects of transport corridors remain limited and present the reasons. [ABSTRACT FROM AUTHOR]

While investigating collisions with immovable obstacles it is necessary to assess the place of contact, its character and the speed of vehicles before the contact. These parameters depend on the obstacle. The most common cases were analyzed in the article: collision with an immovable obstacle which deformed only a part of the fore of vehicle (collision with a tree, a bollard, etc.); collision with an immovable obstacle which deformed the whole fore of vehicle (collision with a wall, etc.). [ABSTRACT FROM AUTHOR]

Probabilistic methods are based on the use of statistical data about mechanical characteristics and lifetime at cyclic loading of a material. In this investigation statistical low cycle fatigue tests were carried out and mechanical characteristics of three materials (steel of grades 15X2MFA and 45 and aluminium alloy D16T1), representing all possible variations of cyclic properties (fatigue, quasi -- static and intermediate mode of fracture) were determined experimentally. Based on the obtained data the analysis of design curves of equal fracture probability for steels 15X2MFA and 45 and aluminium alloy D16T1 at strain low cycle loading was performed and the design curves were compared with the experimental ones. [ABSTRACT FROM AUTHOR]

From a fatigue point of view, the second most important WWER (Water-Water Energetic Reactor) pressure vessel component (after closure studs) are the primary nozzles. These parts are included in the in-service inspection performed every 4 years when non-destructive testing techniques like ultrasonic, eddy-current and dye-penetration methods are applied. After the determination of the severity of fatigue crack, the progress of initial defects over time can be prevented by repair welding. determination of values of the eight main mechanical properties of the welded nozzle after major repair, evaluation of statistical data for reliability and recommendations for the maintenance. the examination of the nozzle Du-500 revealed the presence of perpendicular crack on the outside surface in the base metal. The crack in the base metal has an angle of 72° with the horizontal plane which was repaired at normal (T = 20 °C) and elevated (T = 350 °C) temperatures by (i) automatic arc welding under the flux layer AN-42, and (ii) ceramic flux. The analysis was performed with 15 different batches of welded steel specimens and every single parameter each time was established by using 45 repetitions of the test procedure for the same type of specimen. the study describes the specific case of defected nozzle's housing that was made of steel 15Cr2MoVA and after the crack repair along the length of nozzle diameter could potentially be further exploited. Value – the analysis of the welded specimens showed good agreement between the empirical and theoretical curves and can be used in lifetime and fatigue life predictions for WWER pressure vessels still applicable in power generation industry. • This is the article on weld joint efficiencies in the repaired WWER pressure vessel. • The analysis showed good agreement between the empirical and theoretical curves. • The study describes the specific case of defected nozzle after the crack repair. • Joints welded under ceramic flux showed lower durability. • Ceramic flux cannot be recommended for welding of steel 15Cr2MoVA intended for WWER. [ABSTRACT FROM AUTHOR]

At all the repair enterprises, despite decreased rim wear-off resistance, after every grinding only geometry wheel profile parameters are renewed. Exploit wheel rim work edge decrease tendency is noticed what induces acquiring new wheels. This is related to considerable axle load and train speed increase and also because of wheel work edge repair method imperfection. [ABSTRACT FROM AUTHOR]

The paper presents the durability analysis of the automatic coupler in railway carriages. The loading of the automatic coupler predetermined by the weight of a train, train speed and railway relief is a time-dependent variable. The finite element method was used for stress-strain state calculation taking into account acting forces. In order to reduce stress concentration, the geometry of the automatic coupler's body was modified. Modelling results for different rounded radii demonstrated it was possible to reduce stress concentration up to 34%. Under maximum forces, plastic strain occurs in the automatic coupler's body. The calculation of strain and stress state in the body of the automatic coupler shows it is under a static, low and high cycle loading. Therefore, to calculate the durability of the automatic coupler, the dependencies for low cycle nonstationary stress limited loading has been proposed evaluating low cycle quasi-static and fatigue damages. In order to evaluate high cycle fatigue damage, a linear law for the summation of loading cycles has been suggested. For low cycle damage evaluation, the calculation method for the summation of fatigue and quasi-static damages created at one loading cycle taking into account loading level and neglecting the sequence of cycles has been put forward. Thus, to calculate the automatic coupler for each specific case, it is necessary to determine the number of loading cycles at each loading level and to evaluate durability considering dependencies presented in this paper. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are reviewed in the context of policy and technical aspects taking into consideration the Lithuanian national picture over the global and European Union developments within this field. The paper presents also the best practices for deployment of EVs including the potential niche markets and the challenges and opportunities within the energy and power systems support. A critical evaluation is also performed on the relevant research and developments in Lithuania. Finally, the paper evaluates the strengths, weaknesses, opportunities and threats through a developed SWOT analysis. This review will provide insight to the EVs challenges and opportunities within the Baltic Region. It is expected this will inspire individuals, business and policy makers to allow and incentivise deployment of EVs to enhance efficiency in transport and consequently contribute towards GHG emissions reduction. [ABSTRACT FROM AUTHOR]

The Kaliningrad Oblast experiences severe power shortages. State of the heat and power sector of the Exclave is evaluated as very complicated, largely inconsistent with the requirements of modern standards for the organization and functioning of electric power systems, and largely dependent on the specific geopolitical situation. The present review considers: (i) the differences between social media outcomes regarding the Baltic NPP and presents possible scenarios that could exist in the future as a result of certain policy decisions, (ii) current status of the Region׳s energy sector and possibilities of its transition towards environmental sustainability by means of renewable energy, solid and gaseous biofuels, and local peat, and (iii) necessity of buildings renovation in the Kaliningrad Oblast. The data is collected via personal communications and literature research by structuring complex problems and considering multiple opportunities. The interviewees were educators, scientists and various stakeholders (potential investors and energy contractors, local farmers and agricultural landowners as potential producers of energy crops, etc.). According to their views and literature, background knowledge and critical thoughts on renewable energy solutions for Kaliningrad Oblast are presented. This study will primarily address policy-makers and environmental lobbyists, as they are the shapers of the regulatory and economic situation as well as energy sector׳s development direction in the Region. It will also be of use to those planning on establishing renewable energy production as a comprehensive summary of factors to take into account. [ABSTRACT FROM AUTHOR]

Abstract: This review paper sets the stage for a look at the Lithuanian (hereinafter LT) transport sector and its transition towards sustainable mobility through the use of biofuels and implementation of the necessary policies to deliver the renewable energy targets. The assessment begins with a brief and reasonably balanced situational analysis of the transport subsectors—road (including ex-fleet vehicle market), off-road, railway, marine, and air—in Lithuania, and their direct relations to the biofuel sector. The paper also aims to examine the dynamics of GHG emissions (N2O, CH4, CO2), air and soil pollution (NO2, SO2, NMWOC, NH3, PM, CO, heavy metals), and related indicators in the whole LT transport sector during the economic transition period (1990–1995), economy growth period (1996–2007) and the first-world debt crisis period (2007–2010). The national biofuels industry has seen plenty of ups and downs over the past decade but have generally good growth prospects. The study found that the CO2 emission is growing recently in Lithuania and this growth could be attributed to almost all transport subsectors. One of the main problems responsible for this situation is the patchy nature of the regulation (there is no governmental decision indicated on setting of national fuel economy/GHG standard), from which most other problems arise. Transport activity has been a key facilitator and driver of economic prosperity in Lithuania and it is likely to continue to grow. It can produce both positive and negative effects on the environment and the quality of life depending on measures at all levels to promote its sustainable development. [Copyright &y& Elsevier]

Abstract: District heating sector is one of the most important sectors of Lithuanian energy industry. Consequently, low-cost bioenergy sources could play an important role in developing biofuels based on the so-called second-generation feedstock and decentralized energy supply for remote rural areas with low heat demand density. The present amount of biomass straw is already considerable in Lithuania but the potential is even much higher. It is assumed that the share of firewood in the balance of RES will decrease significantly – from 86.7% in 2009 to 55% in 2020 and future decisions on the acceptability of new substitutes must be found. The most important factors that could hasten the diffusion of straw combustion technologies for heat-only boilers (HOBs) in order to contribute to a local fuel and low-emission energy infrastructure are political issues, reduction in existing technical thresholds, market and economic conditions, international cooperation activity, and broad experience through wood residue combustion. The collected data indicated that under conditions in Lithuania, biomass straw combustion is prospective mainly to be used for heat production in small and medium scale units of 0.6–5.0MWth capacity as well as in large scale installations where multi-biomass strategies are foreseen. [Copyright &y& Elsevier]