This study examines the mechanical properties, specifically strength and stiffness, of technical hemp and flax fibers grown in Romania. Tensile testing was employed to determine stress–strain curves and the Young’s modulus and to assess the failure strength of both fiber types. Although samples of various lengths were tested, no significant length-dependent variations were observed. However, a strong dependence on fiber diameter was noted, with the smallest diameters approaching the documented strength of elementary fibers. Due to the considerable variability in the experimental results pertaining to the characteristics of the reinforced fibers, a statistical analysis using a two-parameter Weibull distribution was employed. The analysis revealed three distinct stress–strain curve profiles, i.e., linear, bi-linear, and tri-linear patterns, with the average ultimate stress ranging from 412 to 566 MPa for hemp and 502 to 598 MPa for flax.

Honeycomb composite materials are widely used in many areas of mechanical engineering where weight saving is a crucial factor. One of the main loads that such material configurations are designed to withstand is compressive load. The most important industrial sector where honeycomb composite materials have found their application is in the aerospace industry, due to their advantages of high strength and lightness. In this article, two forms of finite element model analyses are presented for a novel multilayered honeycomb composite material with impregnated paper cores. The first represents a detailed approach tailored for local analysis, while the second is useful for a global analysis of the honeycomb composite material. Both types of modeling techniques are presented with a description of their advantages and drawbacks, highlighting the increased precision of the complex model—closest deformation estimations—and the agility of the equivalent one—an 80% reduction in complexity, providing acceptable results. An initial comparative analysis is performed, and the obtained results are discussed. An experimental validation is also carried out, followed by the presentation of a suggested practical application, displaying good accordance.

This study presents a comparative investigation of the low‐velocity impact behavior of thin plates made from carbon fiber reinforced polymer (CFRP), polylactic acid (PLA), and acrylonitrile butadiene styrene (ABS). Plates with nominal thicknesses of 0.5 and 5 mm were subjected to standardized drop‐weight impact tests to evaluate their energy absorption capacity, failure modes, and structural response under dynamic loading. The experimental results indicate significant differences between the three materials: CFRP plates demonstrated superior impact resistance and energy absorption efficiency, attributed to their layered fiber structure and brittle failure behavior, while PLA specimens exhibited earlier failure through plastic deformation and crack propagation. The ABS specimens did not exhibit any visible cracks at an impact energy of 2 J, indicating a high capacity for plastic deformation without the immediate occurrence of cracking or fracture. To investigate the failure threshold of the material, the tests were repeated at an increased kinetic energy of 8 J. This step aimed to determine the failure mode and the upper energy absorption limit of the ABS material under intensified dynamic loading. The absorbed impact energy per unit thickness was analyzed to isolate and highlight the intrinsic material behavior, minimizing the influence of thickness variation. Finite element analysis models were developed to simulate the impact response of the tested specimens. The study provides valuable insights for material selection in the design of lightweight structures exposed to low‐velocity impact, with potential applications in aerospace, automotive, and consumer electronics industries.

The study focuses on the experimental determination of the impact behavior of PLA components manufactured through additive manufacturing, where the infill density of each tested specimen is varied. The evaluation of the impact energy absorbed by each configuration provides relevant insights into the influence of internal structure on mechanical performance, thus contributing to the optimization of manufacturing parameters for the development of components that must respect the efficiency in terms of mechanical strength and material use. In this paper, the authors investigate the influence of internal structure on impact strength by proposing four different infill density configurations for 3D‐printed PLA specimens: 30%, 50%, 80%, and 100% infill. These variations were selected to provide a comprehensive understanding of how internal material volume increase affects the mechanical performances under impact loading. By systematically analyzing the absorbed impact energy for each configuration, the study aims to establish correlations between infill percentage and structural integrity, offering valuable insights for optimizing additive manufacturing parameters.