The article highlights the problems associated with design of freight railway cars. In particular, analysis possibilities application polymeric materials as a structural material body relevance this is not in doubt, because improvement technical and economic parameters cars one main tasks car building at time. describes basic methods manufacturing bodies use composite – fiberglass. work carried out detailed physic-mechanical properties identify their advantage over steel. As object research...

The article analyzes the statistics of rubber-cord coupling failures during 2015 till 2022. analysis shows that prevailing cases are rupture side surface. It should be noted cost eliminating consequences a is on average 575.21 EUR for one unscheduled repair. To study possible reasons rupture, couplings removed from motor cars after repairs were taken. In process research, warming temperature coupling, hardness at various temperatures and forces acting operation, i.e. operational conditions...

This study investigates the cyclic load application impact on fly ash-based geopolymer composites that are reinforced with a low amount of fibre reinforcement. For reinforcement purposes, PVA and steel fibres used. testing four composite mixes were made, 3 which had Simultaneously specimens tested for shrinkage, static load-induced creep, creep. creep testing, loaded 20% their strength. release cycles seven days long. When each cycle was introduced, added in steps. In 5 minutes, by 25% steps...

In the article, studies of energy efficiency various technical and biomechanical vehicles are reflected, an analysis use electric bike as main individual vehicle is carried out. Experimental dynamics power presented. The acceleration characteristics were measured by a traction drive estimated at different battery charges. It established that when used source, time to speed 5 m/s decreases with discharge battery. This due decrease in output it discharges voltage increase internal resistance...

The paper describes the experiment during which to evaluate potential time and material economy railway turnout element, in particular stock rail, was restored using two different welding methods – manual metal arc (MMA) currently used by Latvian Railway flux-cored (FCAW). For quality control rails were further examined with metallographic examination. Performed revealed that, if restoration is performed strictly following technical procedures, elements are of equally high quality; however,...

The current investigation presents porous ceramic materials prepared with cenospheres (CS) by using spark plasma sintering. impact of sintering temperature, mould diameter (20, 30 and 50 mm) cenosphere size on the properties sintered material was investigated. Shrinkage samples during started at 900 °C. Total sample shrinkage increases increasing temperature decreases size; apparent density all series CS 63–150 µm in a 20 mm from 0.97 to 2.3 g·cm−3 1050–1300 °C; mould, 0.81–1.87 1050–1200...

One of the main criteria for quality steels is ability to resist brittle fracture. This qualitatively expressed in value impact strength and toughness. According statistical data at AS “Pasažieru vilciens”, low temperatures, number failures M-24 bolts fastening rubber-cord coupling increases. In this regard, urgent task reduce during winter. The article presents results tests toughness, as well a metallographic analysis two steel grades 41Cr4 P355NL1. Also an experiment was carried out, on...

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This study was conducted under the 4R-UAV project. The project is funded by Latvian Council of Science with goal creating an innovative, aerodynamically improved, environmentally friendly, zero waste, and emission UAV. For Circular Aviation 4R (Reduce, Recycle, Reuse, Redesign) concept, this paper covers two Rs (Reduce aspects Topology optimization structures has gained enormous potential advances in additive manufacturing techniques. However, it still challenging when comes to conventional...

Relevance of the research topic. During operation rubber-cord couplings with a toroidal shell form may fail. For period from 2019 to 2023 (5 years) such failures amounted more than 58 cases. According visual inspection large number failed couplings, it was found that cause failure rupture side surface. The aim this scientific article is determine forces and moments acting on coupling, as well displacements shafts connected by coupling in axial, radial angular deflections. To properties...

Abstract The current study introduces porous ceramic materials fabricated from cenospheres through spark plasma sintering. investigation delves into the impact of sintering temperature, mould diameter (20 and 30 mm), cenosphere size on resulting material properties. Notably, sample shrinkage initiates at 900 °C demonstrates an upward trend with temperature escalation, while a larger contributes to shrinkage. Elevated leads increased apparent density across various series, such as CS 63–150...

The article provides statistics on failures of rubber-cord couplings electric trains the ER2 and ER2T series diesel over past 7 years. According to statistics, years, 107 have failed. Of these, largest number cases failure occurred rolling stock series. Examining failed couplings, it was revealed that cause its a rupture side surface. Replacing coupling is labour-intensive costly process. Accordingly, question arises: what causes problem measures should be proposed reduce failures. For these...

This study aims to address the limited understanding of wash oil degradation in benzene units by analysing changes composition and properties fresh operating oils from different manufacturers. The findings will provide insights into pathways stability these oils. Gas chromatography/mass spectrometry was used analyse provided samples, dynamic viscosity determined using a Brookfield LV DV2T rotational viscometer. During operation, “heavy” (HO) becomes less volatile, while ”light” (LO) slightly...

This study investigates the cyclic load application impact on fly-ash-based geopolymer composites that are reinforced with a low amount of fibre reinforcement. For reinforcement purposes, polyvinyl alcohol and steel fibres used. testing four composite mixes were made, three which had Simultaneously, specimens tested for shrinkage, static-load-induced creep, cyclic-load-induced creep. static creep testing, loaded 20% their strength. release cycles seven days long. When each cycle was...

By applying the physical vapour deposition method, hollow ceramic microspheres were coated with titanium, and subsequently, they sintered using spark plasma sintering technique to create a porous material that is lightweight devoid of matrix. The process was carried out at temperatures ranging from 1050 1200 °C, holding time 2 min. samples subjected conventional thermal analyses (differential scanning calorimetry, thermogravimetry, dilatometry), oxidation resistance tests, diffusivity...

The current investigation presents porous ceramic materials prepared of cenospheres by spark plasma sintering. impact sintering temperature, mould diameter (20 and 30 mm diameter) cenosphere size on the properties sintered material was investigated. Shrinkage samples during started at 900 °C. Sample shrinkage increases with increasing temperature decreases size; sample apparent density all series CS 63-150 µm in 20 from 0.97 to 2.3 g·cm-3 1050 - 1300 °C, 0.81 1.87 1200 50 0.54 0.75 1150...

For the first time at Riga Technical University a study was carried out of highly defective frog core grade 1/9. In course research an analysis crossing piece defects on Latvian railway in eight sections during years 2015, 2016, 2017. The defect 1/9 (the 60 E1 DO 07 12 type) considered according to basic classification defects, and cause its fracture were conducted from bolt hole web base core. process consisted four stages:  Stage 1: determination metal hardness Brinell scale with modern...

The article is dedicated to the problem of broken rubber cord coupling bolts, determined on basis statistics traction gear failures for period from 2015 2019 based results AS "Pasažieru vilciens" railway company unplanned repair reports.Due large number unscheduled repairs and general downtime electric motor carriage associated with replacing bolts rubber-cord coupling, question arises quality M-24 gear.As an object under investigation, we used a bolt attaching taken after ER2 8029-02 EMU...

The article reflects information from the field of designing freight railwagons.The issue assembling elements a wagon body made aluminum alloy without welding is considered.The results testing pins with crimp head are presented.Crimp used as an alternative to welding.Such connections have advantages both rivet and bolt connections.They eliminate shortcomings bolted connection, in particular, weakening tension result unscrewing nut during vibration.For correct choice number connections, it...