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 present experimental investigation is aimed at modeling the falling weight impact properties of thermosetting composites produced using a partially bio-based vinylester resin with flax and basalt fibers and using them both in a hybrid configuration, therefore obtaining three different types of laminates, fabricated by hand lay-up and resin infusion. Cure processes were accelerated and controlled by applying heat and pressure in autoclave.\ud After acquiring tensile and flexural data, falling weight impact tests were carried out at several energies of up to 40J, so to induce penetration, but also to have information on the evolution and the different characteristics of damage produced. Modeling analysis was mainly based on the study of impact hysteresis cycles, which correlate the mode of energy absorption, whether quasi-elastic or producing irreversible damage and the rebound characteristics, in case the energy is not sufficient to produce penetration, from the patterns of force vs. displacement curves obtained during impact loading

Cruisers are multi-occupant solar vehicles that are conceived to compete in long-range (over 3,000 km) solar races based on the best compromise between the energy consumption and the payload. They must comply to the race's rules regarding the overall dimensions, the solar panel size, functionality, and safety and structural requirements, while the shape, the materials, the powertrain, and the mechanics are considered at the discretion of the designer. In this work, the most relevant aspects of the structural design process of a full-carbon fiberreinforced plastic solar vehicle are detailed. In particular, the protocols used for the design of the lamination sequence of the chassis, the leaf springs structural analysis, and the crash test numerical simulation of the vehicle, including the safety cage, are described. The complexity of the design methodology of fiber-reinforced composite structures is compensated by the possibility of tailoring their mechanical characteristics and optimizing the overall weight of the car. Video LinkThe video component of this article can be found at https://www.jove.com/video/58525/ A new design philosophy must be approached, including a different vision of material use and manufacturing. First, materials must be selected based on the highest strength-to-weight ratio and, as a direct consequence, carbon-reinforced fiber plastics represent an optimal solution. Furthermore, specific stratagems in the design must be implemented.In the present article, the procedures employed to design some of the most important structural parts of the solar vehicle, such as its monocoque chassis, the suspension, and even a computational crash test are depicted. The final scope is to obtain rapidly a solar vehicle with the least possible weight, in a trade-off with aerodynamics and race rules.

This work searched for the optimal geometrical configuration of simply supported stiffened plates subjected to a transverse and uniformly distributed load. From a non-stiffened reference plate, different geometrical configurations of stiffened plates, with the same volume as the reference plate, were defined through the constructal design method. Thus, applying the exhaustive search technique and using the ANSYS software, the mechanical behaviors of all the suggested stiffened plates were compared to each other to find the geometrical configuration that provided the minimum deflection in the plate’s center when subjected to this loading. The optimum geometrical configuration of stiffeners is presented at the end of this work, allowing a reduction of 98.57% for the central deflection of the stiffened plate if compared to the reference plate. Furthermore, power equations were adjusted to describe the deflections for each combination of longitudinal and transverse stiffeners as a function of the ratio between the height and the thickness of the stiffeners. Finally, a unique equation for determining the central deflections of the studied stiffened plates based only on the number of longitudinal stiffeners without significantly losing accuracy has been proposed.

This study aims to compare the accuracy offered by 3D Slicer Software in printing end-use parts inside a Fused Deposition Modeling process of Additive Manufacturing. The purpose, in particular, is to investigate the surface quality and the dimensional stability of the manufactured parts comparing the effect of selecting a different 3D Slicer tool among Simplify3D, Cura and Slic3r 3D. With this scope, parts were produced using these process tools while results were analysed in terms of accuracy, production time and consumption of material. Results, graphically and visually presented, show significant differences in the dimensional and surface accuracy with an optimum outcome offered by the Simplify3D as best 3D slicer tool. The Simplify3D slicer has essential advantages in printed end-use parts because creates the 3D models with significantly better accuracy and quality support.

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