Objectives: In unattended machining, monitoring the cutting processes holds significant importance. A crucial aspect to consider is whether chip formation occurs at a specific moment or not. Acquiring this knowledge can enhance production reliability and minimize losses. Methods: To address this, an algorithm is proposed for detecting chip formation using vibration signals obtained from a CNC machine. The algorithm relies on the spindle RPM and vibration signal to identify the occurrence of machining cycles (chip formations). The evaluation process involved comparing the results of the algorithm to those obtained by a human manually selecting the machining parts from the same signal. Results: Its effectiveness was evaluated across various feedrates, demonstrating its applicability under different conditions. Conclusions: This method is able to detect the real machining more accurate than the use of G-code-based method.

This paper deals with safety requirements for radiosondes and their possible finite element method (FEM) simulations. This article proposes a soft outer layer, which exhibits the use of a Polyurethane foam (PUR foam) layer on radiosondes. Analysis and tests of normal and PUR foam layer coated radiosonde’s collisions with test targets were done. FEM models were created to model the collisions of radiosondes with virtual targets at drop tests in different scenarios. To compare and verify the virtual results, specified real-life drop test measurements were carried out. The measured data was analyzed and showed an average accuracy of 8% in force measurements, and 2.22% accuracy in duration of the tests. Based on these virtual and real-life tests it was demonstrated, that an FEM model can simulate the end result of using PUR foam layers on radiosondes. It also demonstrated that the applicable PUR foam layer increases a safer collision also increasing the chance of maintaining functionality of the radiosondes.

A munka célja egy egyszerűsített lapátmodell sajátfrekvenciáinak meghatározása méréssel és végeselem szimulációval, egy valós méretű szélerőmű lapát sajátfrekvenciáinak meghatározása továbbá szélerőműlapátról lehulló jég által okozott lengések szimulációja. A feladat kidolgozásához az Ansys szoftver modális és tranziens jelenségek vizsgálatára alkalmas moduljai lettek használva. A modellkísérlet a modális végeselem szimuláció hitelességét igazolja, az egyszerűsített lapátmodell sajátfrekvenciájának meghatározása során a kísérleti és szimulációs eredmények közötti differencia 1% alatti.

Ice shedding from transmission line conductors may result in high-amplitude vibration, which risks the security of different elements of the transmission line. The present study aims to discover how the conductor rebound height on the same transmission line varies during different ice shedding scenarios. The scenarios considered includes (i) partial shedding from mid-span with varying shedding ratio when ice shedding and the resulting motion are symmetric; (ii) partial shedding from either side of the conductor with varying shedding ratio when ice shedding and the resulting motion are asymmetric; (iii) partial shedding from various parts of the conductor with constant shedding ratio, for few values of shedding ratio. Each scenario is repeated assuming that the non-shedding part is loaded or unloaded. Ice shedding scenarios are simulated experimentally in a small-scale laboratory set-up. Ice shedding is modelled by the removal of several loads attached at different positions along the cable. Observations reveal that the highest position of the conductor during vibration following load removal increases with the shedding ratio, but this tendency also depends on the location of shedding. The load on the non-shedding part has vibration suppressing effect locally, but it may even result in enhancing the vibration far from the non-shedding part if long enough part sheds. These tendencies are studied on full-scale transmission lines in further research by constructing a numerical model that is validated by the experiments and then adjusted to simulate ice shedding scenarios on full-scale lines.