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Abstract: V diplomskem delu sta predstavljena konstruiranje in trdnostni preračun tlačnega kanala za polnjenje pijač z ogljikovim dioksidom, ki ga izdelujejo v podjetju Vipoll d. o. o. V začetku so predstavljene teoretične osnove s področja tlačnih posod in polnilne tehnologije. V nadaljevanju so podane specifikacije in 3D model tlačnega kanala, ki je bil izdelan s pomočjo programskega paketa SolidWorks 2023. Predstavljena je analiza modela po metodi končnih elementov, ki je bila izdelana v programskem paketu PrePoMax v2.0.1. Na koncu diplomskega dela sta podana prikaz vseh rezultatov in njihovo vrednotenje.
Keywords: tlačni kanal, trdnostni preračun, numerične analize, polnilna tehnologija
Published in DKUM: 06.05.2025; Views: 0; Downloads: 19
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Abstract: V diplomski nalogi smo v podjetju SIP, d. d., obravnavali problem formiranja zgrabkov pri rotorskih zgrabljalnikih. Glavni fokus naloge je bil na ekonstrukciji sledilnega mehanizma, nameščenega v notranjosti rotorja, ki služi za formiranje zgrabkov. S pomočjo programskega paketa SolidWorks smo izdelali model sledilnega mehanizma ter prilagodil pot le-tega za formiranje lepših zgrabkov. Hkrati sta bila v sklopu rekonstrukcije izdelana nova odkovka, ki služita kot nosilca ležaja, določen je bil tudi nov ležaj, ki se kotali po sledilnem mehanizmu za večjo obstojnost celotnega mehanizma. Rezultate delovanje starega sledilnega mehanizma v primerjavi z novim sledilnim mehanizmom smo primerjali v programskem paketu SolidWorks, pri čemer smo ugotovili izboljšano delovanje novega mehanizma v primerjavi s starim.
Keywords: sledilni mehanizem, rotorski zgrabljalniki, rotor, SolidWorks, konstruiranje
Published in DKUM: 11.04.2025; Views: 0; Downloads: 0

Abstract: The purpose of this article is to present the use of a previously validated wearable sensor device, Armbeep, in a real-life application, to enhance a tennis player’s training by monitoring and analysis of the time, physiological, movement, and tennis-specific workload and recovery indicators, based on fused sensor data acquired by the wearable sensor—a miniature wearable sensor device, designed to be worn on a wrist, that can detect and record movement and biometric information, where the basic signal processing is performed directly on the device, while the more complex signal analysis is performed in the cloud. The inertial measurements and pulse-rate detection of the wearable device were validated previously, showing acceptability for monitoring workload and recovery during tennis practice and matches. This study is one of the first attempts to monitor the daily workload and recovery of tennis players under real conditions. Based on these data, we can instruct the coach and the player to adjust the daily workload. This optimizes the level of an athlete’s training load, increases the effectiveness of training, enables an individual approach, and reduces the possibility of overuse or injuries. This study is a practical example of the use of modern technology in the return of injured athletes to normal training and competition. This information will help tennis coaches and players to objectify their workloads during training and competitions, as this is usually only an intuitive assessment.
Keywords: tennis, training, data-based coaching, shot recognition, wearable device, workload, recovery
Published in DKUM: 31.03.2025; Views: 0; Downloads: 3
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Abstract: Background: City logistics is a critical component of urban economic development, as it optimizes supply chains, enhances customer satisfaction through reliable deliveries, and minimizes environmental impacts in densely populated areas. This field addresses various challenges, including traffic congestion, environmental concerns, noise pollution, and the crucial need for timely deliveries. Routing and scheduling are central to logistics operations, with modern software integrating time windows to meet precise scheduling demands driven by detailed customer requirements and operational efficiencies. Furthermore, advanced vehicle routing models now effectively simulate real-world factors such as traffic congestion, stochastic travel times, and dynamic product demands. Purpose: This paper aims to develop an algorithm that addresses the routing decisions. Our approach extends to the time dimension, considering travel times and customer service times within predefined time windows. Study design/methodology/approach: The proposed algorithm is structured to execute in iterative phases, aiming to optimize key logistical objectives. In order to generate competitive solutions, we seek to minimize the number of vehicles utilized and overall travel costs. The evaluation of solution space was conducted via Simulated Annealing. Findings/conclusions: The performance of the proposed algorithm, evaluated using the Gehring and Homberger benchmark instances for 200 customers, demonstrates its effectiveness. The algorithm successfully meets the target number of vehicles required, and the associated travel costs are on average within 1% of the best solutions reported in the relevant literature. Limitations/future research: Given the ongoing need for timely solutions from decision-makers, future research endeavors will focus on enhancing the computational efficiency of the algorithm. Additionally, incorporating more time-related features, such as stochastic travel times, could further improve the algorithm's real-time applicability.
Keywords: city logistics, vehicle routing, simulated annealing, time windows, scheduling
Published in DKUM: 27.03.2025; Views: 0; Downloads: 2
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Abstract: A comprehensive experimental investigation to understand the mechanical properties and fatigue behaviour of glass-reinforced polyamide (PA66 GF30) at different temperatures is presented in this paper. The specimens for quasi-static and fatigue testing were machined from previously extruded plates, where two orientations were considered: (i) the extrusion direction (ED) and (ii) the direction perpendicular to extrusion (PED). Both the quasi-static and fatigue tests were performed under different temperatures (22 ◦C and 100 ◦C). The fatigue tests were performed in a load control regime under pulsating loading (R = 0.1) to create S–N curves for all the temperatures and loading directions. The experimental results of the quasi-static tests showed that the test specimens manufactured in the extrusion direction have better mechanical properties when compared to those of the specimens manufactured perpendicular to the extrusion direction. Furthermore, the analysis of the quasi-static tensile test results showed that tensile strength, yield strength, and the modulus of elasticity are significantly dependent on the temperature and deteriorate when the temperature is increased from 22 ◦C to 100 ◦C. The results of the fatigue tests showed that at both the temperatures (22 ◦C and 100 ◦C), the samples produced in the direction of extrusion exhibited higher fatigue strength than those produced perpendicular to the direction of extrusion. For all the sample orientations, the fatigue strength decreased significantly with increasing temperature. The obtained experimental results could be very useful when designing and dimensioning different dynamically loaded engineering components made of PA66 GF30 subjected to high temperatures.
Keywords: PA66 GF30, increased temperatures, fatigue, experimental testing
Published in DKUM: 10.03.2025; Views: 0; Downloads: 5
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