The present paper investigates the possibility of replacing the traditional L-type corner joint used in chair construction with a 3D printed connector, manufactured using the Fused Filament Fabrication (FFF) method and black PLA as filament. The connector was designed to assemble the legs with seat rails and stretchers, and it was tested under diagonal tensile and compression loads. Its performance was compared to that of the traditional mortise-and-tenon joint. Stresses and displacements of the jointed members with connector were analyzed using non-linear Finite Element Method (FEM) analysis. Both connector and mortise-and-tenon joint were employed to build chair prototypes made from beech wood (Fagus sylvatica L.). Digital Image Correlation (DIC) method was used to analyze the displacements in the vicinity of the jointed members of the chairs. Seat and backrest static load tests were carried out in order to verify if the chairs withstand standard loading requirements. Results indicated that the 3D printed connector exhibited equivalent mechanical performance as the traditional joint. The recorded displacement values of the chair with 3D-printed connectors were higher than those of the traditional chair reaching 0.6 mm on the X-axis and 1.1 mm on the Y-axis, without any failures under a maximum vertical load of approximately 15 kN applied to the seat. However, it successfully withstood the loads for seating and backrest standard tests, in accordance with EN 1728:2012, without any structural failure. This paper presents a new approach for the chair manufacturing sector, with potential applicability to other types of furniture.

The emergence, development and application of the hybrid strategy both by non-state and state actors play a particular role in the evolution of military conflicts. The proliferation of hybrid risks and threats requires the identification and improvement of integrative security solutions, both, nationally and internationally, as well as in terms of instruments. Consequently, the present article aims to identify the stages and some of the fundamental principles of hybrid conflict planning and development.

The purpose of the research is to develop a model for the analysis of investments in connectivity. The developed model allows a more accurate capture of the impact of sources of fluctuations in investment projects aimed at increasing connectivity, using Wiener Processes and Poisson distribution. The results are solutions for improved decision-making in aviation infrastructure to the benefit of the regional economy.