https://popups.uliege.be/esaform21/index.php?id=1973 Publications of Auteurs Davide Mocerino fr 0 https://popups.uliege.be/esaform21/index.php?id=4044 Gypsum is an ancient material, still widely used and suitable for many applications in the constructions due to its low cost, availability, lightweight, good thermal and sound isolating behaviour, fire resistance and low energy consumption. One of the most established application is its use as building walls and as pointed out in authors previous research works, it can be very useful and interesting to reinforce the gypsum with vegetable fibres like hemp. This aspect is in line with the current world situation where every industrial company needs to decrease the materials waste, increase recyclability and use more eco-friendly materials. Therefore, this work aims at designing, manufacturing, and testing of both commercial and recycled gypsum specimens reinforced with hemp fabrics, in order to improve impact and flexural resistance of traditional gypsum boards. The recycling process was carefully studied to detect the best grinding time, temperature and time of the heat treatment required to allow the reutilization of gypsum powders. Three point bending and impact tests at different energy levels were carried out in order to understand how the presence of the hemp fabrics within the gypsum matrix and how the recycling process affect the mechanical response of reinforced gypsum. Tue, 30 Mar 2021 10:58:08 +0200 Tue, 30 Mar 2021 10:58:08 +0200 https://popups.uliege.be/esaform21/index.php?id=4044 https://popups.uliege.be/esaform21/index.php?id=2651 The use of composite hybridization using both synthetic and natural fibers, is one of the most established way to combine the advantages of each material that forms the composite system in order to obtain a composite with good in-plane and out-of-plane properties. For example, as pointed out in authors previous research works, considering carbon/hemp hybrid composites, it is possible to combine the ductile behavior and the capacity to absorb energy of hemp fibers with the higher strength and stiffness of carbon allowing the development of a hybrid system with enhanced energy absorption capability, reduced production cost and lower environmental impact respect to traditional carbon fibers composites. The aim of this work is to investigate both experimentally and numerically the mechanical behavior at impact of pure carbon, pure hemp and carbon/hemp hybrid composite laminate. Low velocity impact tests at 10 J and 20 J were carried and non-destructive analyses were performed for each impact energy to evaluate the internal damage extent. The same tests were numerically simulated with LS-DYNA software using shell elements and different material cards (i.e. MAT 54/55, MAT 24 depending on typology of fibers) and contact conditions in order to find the best configuration that matches the experimental results. Wed, 24 Mar 2021 18:37:18 +0100 Fri, 09 Apr 2021 10:38:58 +0200 https://popups.uliege.be/esaform21/index.php?id=2651 https://popups.uliege.be/esaform21/index.php?id=2616 Literature reports several works concerning the impact response of composites reinforced with woven fibers and the mechanisms involved in impact energy dissipation. However, even if composites' structures are subjected to various environmental conditions during their service life, few papers are concerned about the impact behaviour at shallow temperatures. Very few discuss sandwich components. In this paper, sandwich composites' low-velocity impact behaviour constructed from carbon fibre reinforced face sheets surrounding a polyvinyl chloride core has been tested. Impact tests at penetration and indentation (U=5,7.5,12,10 and 15J) at room temperature and -55°C, +70 °C were carried out. After each impact test, indentation depth and ultrasound analysis measurements have been implemented to learn the damage modes of the tested samples. The results provided a useful indication on the extreme temperature's influence on both impact properties and damage evolution. Wed, 24 Mar 2021 18:31:40 +0100 Sat, 10 Apr 2021 13:19:58 +0200 https://popups.uliege.be/esaform21/index.php?id=2616