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.
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>
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