Evolution FP7 funded project: body structure design strategies using new composite and aluminium materials and enabled technologies

Based on Pininfarina Nido EV concept, EVolution aims to reduce the vehicle weight through new materials and process technologies, focused on five demonstrators: underbody, front crossbeam, mechanical subframe, shotgun system and door. This paper refers to body structure design strategies using new composite, Al materials and enabled technologies, focusing in particular on demonstrators design and manufacturing. The new front crossbeam geometry of the front shell is adapted starting from the Nanotough design, while the rear shell is specific for EVolution. The subframe demonstrator is redesigned to fulfil mechanical requirements of the part and manufacturing feasibility either. The EVolution door concept consists of two semistructural composite skins including a structural Al frame. The underbody is conceived through an integrated approach, optimising each element for its function. The shotgun component is designed to link parts obtained with different manufacturing technologies and several aluminium alloys in one single component: the structural node demonstrator.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 314744

Light Microscopy of Medium-Density Rigid Polyurethane Foams Filled with Nanoclay

Practical applications and mathematical modelling of the physical and mechanical properties of medium-density rigid polyurethane foams require knowledge of their structure. It is necessary to determine structural characteristics without destroying the foams and measuring each element. A methodology is described for the use of light microscopy on environmentally sustainable, medium-density rigid polyurethane foams (in the density region of ≈210–230 kg/m3), by the analysis of two types of light microscopy images: (1) Cutting surface images; and (2) Through-cutting surface images. The dimensions of structural elements of polyurethane foams, filled with the nanoclay Cloisite-30B at concentrations of 0.0%, 0.25%, 0.50%, 1.0%, 2.0%, 3.0%, and 5.0% from the mass of the filled reacting mixture, are estimated. Probability density functions of projections of bubbles’ diameters and struts’ length are determined using images in three mutually perpendicular planes. A mathematical model is developed for the restoration of the actual dimensions of bubbles’ diameters using data of cutting circles’ diameters. Intercalation and exfoliation of the filler’s Cloisite-30B mono-layers is evaluated via the basal spacing by X-ray diffraction at a 5 wt.% concentration of nanoclay

The Effect of Manufacture Process on Mechanical Properties and Burning Behavior of Epoxy-Based Hybrid Composites

The production of hybrid layered composites allows comprehensive modification of their properties and adaptation to the final expectations. Different methods, such as hand lay-up, vacuum bagging, and resin infusion were applied to manufacture the hybrid composites. In turn, fabrics used for manufacturing composites were made of glass (G), aramid (A), carbon (C), basalt (B), and flax (F) fibers. Flexural, puncture impact behavior, and cone calorimetry tests were applied to establish the effect of the manufacturing method and the fabrics layout on the mechanical and fire behavior of epoxy-based laminates. The lowest flammability and smoke emission were noted for composites made by vacuum bagging (approximately 40% lower values of total smoke release compared with composites made by the hand lay-up method). It was demonstrated that multi-layer hybrid composites made by vacuum bagging might enhance the fire safety levels and simultaneously maintain high mechanical properties designed for, e.g., the railway and automotive industries