For reasons of energy saving and pollution reduction, there is a growing interest in the development of lightweight structures manufactured with materials of natural origin and recyclable. Agglomerated cork is a mixture of natural cork and an organic binder, and can be considered an alternative to polymeric foams used in structural applications with a high capacity of energy absorption. One of these applications involves impact-absorbing elements in vehicles, which are subjected mainly to dynamic compressive loads. In this work, the dynamic crushing behaviour of agglomerated cork was experimentally studied, analysing the influence of the specimen thickness on the energy-absorption capacity, contact force, displacement, and strain. Dynamic crushing tests with specimens of four different thicknesses were performed in a drop-weight tower. An increase in the maximum contact force, displacement, and strain was observed when the impact-energy/thickness ratio increased. For each specimen thickness a linear variation of the maximum displacement and energy absorbed with the impact-energy/thickness ratio was found. It was observed that the energy absorbed by agglomerated cork did not depend on the specimen thickness, but only on the impact energy.Publicad

Damage evolution of notched composite laminates is analysed in this work using a discrete damage model, which estimates matrix damage evolution and fibre failure. The fibre damage is regularised with a Weibull distribution, and a Regula Falsi method has been used to improve numerical convergence. The model is compared and validated with several experimental results taken from the scientific literature, which consider different materials, laminate stacking sequences and specimen geometries. A good correlation has been found for the failure strength and the stress strain curve of notched and un-notched laminates subjected to in plane loads. The influence of the Weibull modulus on the matrix and fibre damage evolution, and the failure strength, is analysed. (C) 2015 Elsevier Ltd. All rights reserved.Peer ReviewedPostprint (author's final draft