The aim of the present paper is that of conducting a study on the basis of which the optimal parameters for the manufacturing of polymer parts by means of the single point incremental forming process can be chosen in such a way that the process forces have minimum values. Two polymeric materials with a 3 mm thickness, polyamide and polyethylene, were chosen for the analysis. The other input parameters that were considered were: the punch diameter, the step on vertical direction and the wall angle. The Taguchi method was chosen for the design of experiments. Each of the input parameters, except for the material, were varied on three levels—for the punch diameter: 6 mm, 8 mm and 10 mm; for the step on vertical direction: 0.5 mm, 0.75 mm and 1 mm; and for the wall angle: 50°, 55° and 60°. Forces were measured in the three directions of the coordinate axes and the results were analyzed based on the signal-to-noise ratio and an analysis of variance with the aim of minimizing the values of the forces. Considering the input parameters analyzed, it was concluded that the forces are most influenced by the material, followed by the punch diameter, the step on vertical direction and the wall angle.

Polymeric materials are increasingly used in the automotive industry, aeronautics, medical device industry, etc. due to their advantage of providing good mechanical strength at low weight. The incremental forming process for polymeric materials is gaining increasing importance because of the advantages it offers: relatively complex parts can be produced at minimum cost without the need for complex and expensive dies. Knowing the main strains and especially the thickness reduction is particularly important as it directly contributes to the mechanical strength of the processed parts, including in operation. For the design of experiments, the Taguchi method was chosen, with an L₁₈ orthogonal array obtained by varying the material on two levels (polyamide and polyethylene) and the other three parameters on three levels: punch diameter (6 mm, 8 mm and 10 mm), wall angle (50°, 55° and 60°) and step down (0.5 mm, 0.75 mm and 1 mm). The output parameters were strain in the x direction, strain in the y direction, major strain, minor strain, shear angle and thickness reduction. Two analyses were conducted: signal-to-noise ratio analysis with the smaller-is-better condition and analysis of variance. The optimum values for which the thickness was reduced were the following: wall angle of 50°, punch diameter of 10 mm and step down of 0.75 mm.

The present paper aims the theoretical study, using the finite element method, on the single point incremental forming process of two polymeric materials: polyamide 6.6 and high-density polyethylene. The experimental researches used for the determination of the true stress - true strain curves for two materials are presented, which are necessary for their introduction into the simulation. The explicit analysis is carried out with the Ls-Dyna program and the results of the analysis were focused on the major strain, minor strain, thickness reduction, forces on the process and total energy consumed in the process.

The present paper proposes a numerical-experimental comparative study on the single point incremental forming process. A DC04 steel sheet with a thickness of 0.6 mm was used for both the numerical simulation using the finite element method and the experimental research. The type of trajectory used was a spiral trajectory and the finished part obtained was a truncated cone-shaped part. The analysis program used for simulation was Ls-Dyna. The simulations were performed in several variants: with a fixed mesh and with an adaptive mesh, using two different element formulations: 25 (Belytschko-Tsay formulation with thickness stretch) and -16 (fully integrated shell element modified for higher accuracy) and two contact types: automatic surface to surface (ASTS) and forming one way surface to surface (FOSS). The results of the numerical analysis and of the experimental research were focused on determining the major strain, minor strain, thickness reduction and forces at the end of the single point incremental forming process, as well as determining the processing time.

This study explores the relationship between academic motivation, Machiavellian traits, and lying tendencies among Romanian engineering students, with a focus on how these psychological variables influence academic performance. Data were collected from 706 students using the MUSIC Model of Motivation, the Machiavellianism Scale, and the Lie Attitude Questionnaire. Statistical analysis included Spearman correlations, regression models, and moderation analysis using PROCESS Macro (Model 7). The results showed significant negative correlations between Machiavellianism and all five motivational dimensions (e.g., ρ = −0.259 for Empowerment, p < 0.001), as well as between lying tendencies and motivation (e.g., ρ = −0.206 for Empowerment, p < 0.001). Surprisingly, Machiavellianism had a positive effect on academic grades (β = 0.107, p = 0.043), suggesting strategic academic behavior. Motivation was a stronger predictor of performance among female students. These findings highlight the importance of promoting ethical, intrinsic motivation in university settings and call for thoughtful integration of behavioral variables into academic success models.