The present experimental investigation is aimed at performing an analysis of mechanical and impact properties of flax and basalt fibres and their hybrids using a vinylester resin to produce reinforced thermosetting composites. Laminates were fabricated by hand lay-up and resin infusion. Cure processes were accelerated and controlled by applying heat and pressure in autoclave. Tensile, flexural and falling weight impact tests were carried out, the latter with energies of up to 40 J. The results indicated that hybrid laminates did not mostly offer properties to the level predicted by an application of the rule-of-mixtures, especially as regards flexural performance. On the other side, advantages provided concerned in particular reducing the brittleness of basalt offering some evidence of plastic behaviour, especially related to the fact of flax fibre reinforced laminated providing a quite long period at quasi constant load during impact tests, therefore resulting in delayed failure, while extensive damage is produced. The results tend to challenge the idea that basalt/flax fibre hybrid laminates would offer a good performance only with the presence of basalt fibres in the outer layers and would suggest the possible adoption in future of more complex stacking sequences, involving intercalation of flax and basalt layers.

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The rising concern about environmental issues and the need to find a realistic alternative to glass or carbon-reinforced composites have led to an increased interest in polymer composites filled with natural-organic fibers, derived from renewable and biodegradable sources. The scope of this article is to raise awareness regarding the current scientific and technological knowledge on these so-called green composite materials in order to support their larger application in a number of industry sectors. The general state-of-the-art in terms of green composites is proposed, together with some experimental evidence on the mechanical properties of various ecological materials. As a practical demonstration of this sustainable technology, the adoption of green composites as a valid replacement for fiberglass in sailing applications is also described. This article will, in fact, illustrate, step by step and in great detail, the Wet Lay-up Hand Laminating process used, together with Vacuum Bagging, to realize a yacht deck hatch out of ecological composite materials.

The ability to accurately predict the mechanical properties of metals is essential for their correct use in the design of structures and components. This is even more important in the presence of materials, such as metal cast alloys, whose properties can vary significantly in relation to their constituent elements, microstructures, process parameters or treatments. This study shows how a machine learning approach, based on pattern recognition analysis on experimental data, is able to offer acceptable precision predictions with respect to the main mechanical properties of metals, as in the case of ductile cast iron and compact graphite cast iron. The metallographic properties, such as graphite, ferrite and perlite content, extrapolated through macro indicators from micrographs by image analysis, are used as inputs for the machine learning algorithms, while the mechanical properties, such as yield strength, ultimate strength, ultimate strain and Young’s modulus, are derived as output. In particular, 3 different machine learning algorithms are trained starting from a dataset of 20–30 data for each material and the results offer high accuracy, often better than other predictive techniques. Concerns regarding the applicability of these predictive techniques in material design and product/process quality control are also discussed.

The use of light composites when designing fast moving parts for machine tools is emerging as a very efficient solution for improving productivity. Nevertheless several aspects of these materials have to be carefully considered in woodworking. This paper aims to investigate the effect of interleaved nanofiber on mode I interlaminar properties and the failure modes that occur in this mode. For this purpose, woven carbon/epoxy laminates with and without Polyvinylidene difluoride nanofibers in the mid-plane were subjected to mode I interlaminar loading and the results were compared with each other. Acoustic Emission technique was also utilized for better understanding of the failure modes that occurred in the virgin and nanofibersmodified specimens. Mechanical data and acoustic emission parameters associated with pattern recognition analyses were used for investigation of the interlaminar properties and the occurred failure modes. The mechanical results showed that the electrospun nanofibrous mat was able to increase the GIC by 98%. The AE results highlighted that different failure modes were the origin of different interlaminar failure behaviors. Different percentages of the failure modes in the 2 modified specimens compared with the virgin ones were observed. Furthermore, the number of occurred interlaminar failure modes diminished in the modified composite layers.

This paper postulates that the effect of e-commerce on firm performance is not direct and needs to be examined using mediating factors. The Ordinary Least-Squares (OLS) model was employed with the data of the Flash Eurobarometer 439 Survey entitled The Use of Online Marketplaces and Search Engines by small and medium enterprises. The obtained findings provide support for the mediating hypothesis. To be more precise, while the relationship between e-commerce and firm performance is negative, it is positively mediated by certain types of internet sales channels. In particular, the benefits of e-commerce in terms of higher sales are more pronounced when firms use commercial websites and online marketplaces. On the other hand, the interaction between e-commerce and search engines has an insignificant effect on firm performance. This study advances research on e-commerce by emphasizing the importance of mediating effect.

This paper analyzes the possibility to substitute the gray iron, traditionally used for the production of relevant parts in woodworking machines, with ductile iron or vermicular iron. A large experimental campaign to determine the mechanical beavior of ductile and vermicular irons respect to tensile, fatigue, and fracture loads was conducted and the microstructures were also analyzed. Results show that ductile or vermicular cast iron in parts and components of machine tools could provide additional stiffness and resistance for the high precision woodworking respect to Gray Iron. A balanced utilization of these alternative irons would permit to take a full advantage by each specific property (as strength, hardness, weight, etc.).

The aim of the present experimental investigation was to perform a comparative analysis concerning the influence on mechanical properties of natural fibers and/or bio-resins in reinforced thermoset composites. Flax and basalt fibers were selected as natural reinforcements, as single constituents or in hybrid combination. Glass synthetic fibers were used for comparison. Eco-friendly matrixes, both epoxy or vinylester, were considered and compared with composites based on traditional resins. Samples were fabricated by hand lay-up and resin infusion techniques. Cures were accelerated and controlled by applying heat and pressure in autoclave. Tensile, flexural and impact tests were carried out according to ASTM standards.