Products and services with innovative potential
• Lightweight composite structures
• Lightweight metal structures
• Optimization of mechanical structures
• Hybrid composite materials reinforced with natural fibres and glass fibres
• Lightweight composite structures
In the figure below we present a pyramidal cellular structure, made of PET (polyethylene terephthalate) reinforced with carbon fibres.
The structure is obtained by a process of thermal consolidation under pressure of fabrics in which both carbon fibres and PET are found in the form of filaments, without the need for other additives (e.g. resins). During the heating of the fabric, the PET melts and coats the carbon fibres. After cooling, a series of cuts and perforations are made on the plate, which finally allow the mechanical expansion of the structure. By attaching side faces made of the same material, a sandwich structure is obtained. The same structure can be made of an easily recyclable material - PET reinforced with PET (own reinforced PET).
Also, a second-order hierarchical sandwich structure with a prismatic cell core that can be obtained entirely from PET in three different forms: PET fibres, PET matrix and PET foam.
This geometric configuration achieves an increase in the critical buckling force at compression stresses on the sandwich panel.
Another structure is the honeycomb type in which part of the cell walls are composed of sandwich structures - PET foam core flanked by PET-reinforced PET coatings, to increase the absorption capacity of impact energy.
The favorable behaviour of these cellular structures at dynamic stresses - impact - is supported by the high ductility of the base material - PET. In addition, the developed structures have a high recycling potential.
• Lightweight metal structures
A new type of cell core is produced by the mechanical expansion of a sheet of sheet on which interleaved cuts and perforations have been previously applied so that, after exhalation, an open cell network is obtained.
The sandwich panel is then obtained by flanking the expanded cell core with two side coatings and consolidating the connection between them by a method of joining (gluing with adhesives, spot welding).
The ability of materials and structures to dissipate the impact energy generated by dynamic forces is of great interest in applications in the vehicle industry, to increase the safety of passengers or goods. The cellular structures made have a high potential in attenuating impact energies.
• Optimization of mechanical structures
The performance of mechanical structures and systems is given by the degree of refinement of the concept and can be achieved either by going through several design iterations or by finding optimal solutions based on optimization algorithms, in which case an optimal solution can be reached. in a shorter time. Based on these premises, the development and application of techniques for optimizing mechanical, monolithic or composite structures was carried out, which includes multiple objectives such as minimizing weight, costs, maximizing rigidity and strength in relation to its own weight, etc. (e.g. chassis optimization of an electric vehicle made of composite materials).
• Hybrid composite materials reinforced with natural fibres and glass fibres
One of the innovative contributions of our Centre refers to the study of mechanical properties for structures made of hybrid composite materials.
The structure has layers reinforced with both glass fibres and wood fibres, thus maintaining the advantages of both types of fibres. Such composite materials can be used for the manufacture of: panels as interior design elements in construction; panels for the acoustic protection of human habitats located in the vicinity of highways; thermal insulation panels and components of indoor furniture or garden furniture.
Our Centre team used the material to manufacture the seat-back component of a chair that can be used as garden or terrace furniture. Such products are always exposed to environmental factors (humidity, temperature, thermal cycles, etc.). The effect of environmental factors on mechanical properties depends on the species of wood from which the fibres come and their size. In this context, the material studied in our Centre was tested after different periods of immersion in water, and it was found that the material absorbs 1.9% water after 6572 hours of immersion in water and the modulus of elasticity decreases by 9% due to absorption of water.
Structure of hybrid composite material reinforced with wood fibres and glass fibres
Seat-back component for chair, made of composite material reinforced with fiberglass and wood fibres
