3D geometric modelling of discontinuous fibre composites using a force-directed algorithm

A geometrical modelling scheme is presented to produce representative architectures for discontinuous fibre composites, enabling downstream modelling of mechanical properties. The model generates realistic random fibre architectures containing high filament count bundles (>3k) and high (~50%) fibre volume fractions. Fibre bundles are modelled as thin shells using a multi-dimension modelling strategy, in which fibre bundles are distributed and compacted to simulate pressure being applied from a matched mould tool. FE simulations are performed to benchmark the in-plane mechanical properties obtained from the numerical model against experimental data, with a detailed study presented to evaluate the tensile properties at various fibre volume fractions and specimen thicknesses. Tensile modulus predictions are in close agreement (less than 5% error) with experimental data at volume fractions below 45%. Ultimate tensile strength predictions are within 4.2% of the experimental data at volume fractions between 40%-55%. This is a significant improvement over existing 2D modelling approaches, as the current model offers increased levels of fidelity, capturing dominant failure mechanisms and the influence of out-of-plane fibres

Scaling the Non-linear Impact Response of Flat and Curved Composite Panels

The application of scaling laws to thin flat and curved composite panels exhibiting nonlinear response when subjected to low-velocity transverse impact is investigated. Previous research has shown that the elastic impact response of structural configurations exhibiting geometrically linear response can be effectively scaled. In the present paper, a preliminary experimental study is presented to assess the applicability of the scaling laws to structural configurations exhibiting geometrically nonlinear deformations. The effect of damage on the scalability of the structural response characteristics, and the effect of scale on damage development are also investigated. Damage is evaluated using conventional methods including C-scan, specimen de-plying and visual inspection of the impacted panels. Coefficient of restitution and normalized contact duration are also used to assess the extent of damage. The results confirm the validity of the scaling parameters for elastic impacts. However, for the panels considered in the study, the extent and manifestation of damage do not scale according to the scaling laws. Furthermore, the results indicate that even though the damage does not scale, the overall panel response characteristics, as indicated by contact force profiles, do scale for some levels of damage

The renovation of the heliotherapy colony of Cremona: an itinerary to the future

Cremona is a town founded on the left bank of the Po River, near the middle of the Po Valley, about 80 miles from Milan. The river banks became easily accessible at the end of the XIX century thanks the "Po avenue" construction and in the Thirties were built the masonry seats of the rowing clubs Baldesio and Bissolati, followed by the heliotherapy health camp “Colonie del Po". So was born the “Modern riverside” along the towpath. Still today the riverside is the destination for walking or cycling in every season, as well as a meeting place for members of the private rowing clubs. In this context, the former heliotherapy colony and its park, owned by the Municipality of Cremona, is the only public space available to the community. This building is, at the same time, the weak point and the potential of the riverside: it requires, in fact, an urgent restoration and a better use destination. The goal is to create a River Park with Visitor Center: it will house a permanent exhibition about the history of the “Modern riverside” and his link with the similar building in the Cremona territory, because in the thirties were built many heliotherapeutic colonies as the number of the Municipalities in the Cremona Province. In addition to the visitor center, the building will house also a public bar-restaurant and, in the garden, a public summer bar and solarium, swimming pool and bike sharing. This will be the way to connect the riverside and the city center in a new bigger itinerary that can be linked to the VENTO project, the touristic bicycle path Turin-Venice promoted for Expo 2015 by the Politecnico di Milano (Department Dastu), which already adhere the Municipality of Cremona and the clubs Baldesio and Bissolati. The first step to promote the entire project consists of 5 conferences about the riverside and the Modern that the Cremona Professional Body of Architects will held next year, 2014, to stimulate the community interest