The paper presents the results of a students’ survey carried out at “Vasile Alecsandri” University of Bacau, Romania, on the quality of educational process on online platforms in the context of the COVID-19 pandemic. The study was addressed to students from the Faculty of Engineering and the Faculty of Physical Education and Sports. The results of survey highlighted that most of students were satisfied with the measures taken by the university during the lockdown period and the way the teaching—learning-assessment process took place. However, some negative aspects were reported as: lack of an adequate infrastructure for some students, less effective teacher-student communication and interaction, impossibility of performing practical applications, lack of socialization, lack of learning motivation, less objective examination (e.g., possibility of cheating), possibility of physical and mental health degradation (e.g., too much time spent in front of screens, installation of a sedentary lifestyle). Consequently, for the new academic year, effective, and efficient measures must be implemented by the management of the university to remove, as much as possible, these negative issues and to improve the performance of online educational process.

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The aim of the present work was to investigate the residual stresses distribution within parts processed by single point incremental forming (SPIF) as a function of the working parameters and to determine its influence on the parts accuracy. The study was performed for a double frustum of pyramid made by 304 stainless steel. An experimental analysis was first conducted by using the strain-rosette method. Since the method allowed determining the residual stresses only locally, a numerical model was then elaborated to inspect the distribution of residual stresses throughout the whole part. It was found that a favorable state of residual stresses and implicitly a good accuracy of parts can be obtained when small values of tool diameter and tool vertical steps, respectively high values of feed rate and spindle speed, are used.

Single point incremental forming (SPIF) is a process during which at any moment a very small part of the sample is actually being formed. This progressive highly localised deformation is performed by a simple tool, whose trajectory is numerical controlled by a CNC machine. Since no support for the metal sheet is used during forming, large levels of deformation occur, which in turn, induce highly non-uniform residual stresses that affect the accuracy of the processed parts. The aim of the present paper was to inspect, experimentally and by simulation, the state of the residual stresses induced in SPIFed double frustums of pyramids made by A1050. The hole drilling method was used for the experimental measurements and the LS-Dyna software for simulation.

<p>The aim of the current work was to analyse the influence of the process parameters (tool diameter, size of the vertical step of tool, feed rate and spindle speed) on the quality of the processed surface, expressed in terms of roughness and macrostructure in the case of parts processed by single point incremental forming. The analysis was made on A1050 aluminium metal sheets. The obtained results revealed that the process parameters influence differently the surface quality, the worst influence being exerted by the increase of the vertical step of tool. </p>

The aim of this paper is to enrich the knowledge related to the single point incremental forming (SPIF) process by evaluating the efficiency of two optimization methods - the response surface method and the neural network method - to improve the accuracy of manufactured parts by prescribing a proper combination of the process parameters. The analysis is performed for a double frustum of pyramid made by stainless steel. It was found a good ability of prediction of both methods, demonstrating their suitability for physical implementation in solving problems associated to the SPIF process.

Abstract. The aim of the current paper is to determine the influence of material thickness on the quality aspects of AWJ processing of the AL6061T651 alloy. The analysis is performed under different working conditions. The parameters taken into account to quantify the quality of processing are those defined in the ISO/WD/TC 44 N 1770 standard: width of the processed surface at the jet inlet (Li), width of the processed surface at the jet outlet (Lo), deviation from perpendicularity (u), inclination angle (Į) and roughness (Ra). The obtained results emphasise a significant influence of material thickness on both, the surface quality and process productivity.

Abrasive water jet processing is one of the newest unconventional technologies. It can be used to cut different metallic materials (steel, titanium alloys, aluminium alloys, brass) or non-metallic materials (wood, plastics, glass, stone, granite etc.). Therefore, this technology can be successfully applied in different industries as: food industry, wood industry, aeronautic industry, automobile industry, mining industry. Between the advantageous of abrasive water jet processing technology it is worth noticing the following: it is rapid, very small processing forces are generated, it is silent, no thermal distortions occur. The aim of the current paper was to determine the influence of the feed rate on the quality of surfaces processed by AWJ at high pressure. The parameters that quantified the quality of the processed surface were those defined in the ISO/WD/TC 44 N 1770 standard: width of the processed surface at the jet inlet (Li), width of the processed surface at the jet outlet (Lo), deviation from perpendicularity (u), inclination angle (α) and roughness (Ra).