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A novel multi-scale numerical model for the simulation of high-velocity impacts on laminated composite plates is developed, which encompasses a micromechanics module for the accurate assessment of damage initiation and growth in the individual composite micromechanical constituents and for the efficient inclusion of strain rate effects into the analysis. A series of woven carbon/epoxy plate specimens impacted by steel ball impactors of high velocities and energies reaching and exceeding the ballistic limit (m=110 g, v=60-100 m/s, E=200-500 J) are also investigated. Ultimately, key impact simulation results, such as the ballistic limit and induced impact damage, are correlated with representative experimental results, demonstrating the validity of the proposed impact model.

The continuous growth of renewable energy and the transition to a more de-centralised electricity generation adds significant complexity to balance power supply and demand in the grid. These imbalances are partially compensated by demand response programs, which represent a new business opportunity in the building sector, especially for ESCOs. Including demand response to their traditional energy efficiency-based business model adds an additional revenue stream that could potentially shorten payback periods of energy renovation projects. This paper introduces this new dual-services business model, and evaluates the potential suitability of HVAC, generation and storage technologies to ensure proposed energy efficiency and flexibility goals. This paper is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 745594. This paper reflects only the author´s views and neither the Agency nor the Commission are responsible for any use that may be made of the information contained therein

In this work, the mode I fracture toughness of dissimilar metal-composite adhesive joints is experimentally investigated using the double cantilever beam (DCB) test. The particular joint under study is resulted by the adhesive joining of a thin titanium sheet with a thin carbon fiber reinforced plastic (CFRP) laminate and is envisioned to be implemented in the hybrid laminar flow control system of future aircraft. Four different industrial technologies for the joining of the titanium and CFRP adherents are evaluated/compared; co-bonding with and without adhesive and secondary bonding using either thermoset or thermoplastic CFRP. The vacuum-assisted resin transfer molding (VARTM) technique is employed for the manufacturing of the panels. After manufacturing, the panels are cut into test specimens that, because they are too thin (approximately 2.4 mm thick), needed to be stiffened from both titanium and composite sides with two aluminum backing beams to ensure the non-yielding of the titanium during the subsequent DCB tests. Towards the determination of the fracture toughness of the joint from the experimental data, an analytical model recently developed by the authors, that considers the bending-extension coupling of both sub-laminates constituting the test specimen as well as the manufacturing-induced residual thermal stresses, is applied. For the four manufacturing options (MO) investigated, the load-displacement behaviors, failure patterns, and fracture toughness performances are presented and compared. Comment: 10 pages, 6 figures, conference proceedings

In the present work Life Cycle Analysis (LCA) and Life Cycle Costing models (LCC) were developed for quantifying the financial and environmental performance of different material (carbon fiber reinforced thermosetting and carbon fiber reinforced thermoplastic composites) and manufacturing scenarios (autoclave, RTM and CDF) associated with the production of aeronautical structural components. To validate the models developed, they were implemented for the case of a helicopter’s canopy. The results from the analysis pointed out the environmental and financial 1advantage of producing the canopy from carbon fiber reinforced thermosetting composites involving RTM as the manufacturing process. On the other hand, the environmental and financial viability of the scenarios including thermoplastic composites as the material of choice is impaired from both the high embodied energy and raw material cost of PEEK. However, potential benefits from thermoplastic composites like recyclability and reusability as well as the high production rates that they offer and not taken into account in this study could improve their environmental and financial viability. This underlines the need to include potential reusing and recycling applications of the composites, as well as circular economy considerations to the criteria for designing an aircraft structure, selecting the material for this structure and finally manufacturing the structure.

In the present work, Life Cycle analysis (LCA) and Life cycle costing (LCC) models were developed in order to quantify the environmental footprint and cost and thus compare different manufacturing scenarios associated with the production of aeronautical structural components. To validate the models developed, they were implemented for the case of a helicopter's canopy processed by two techniques commonly used in aeronautics, namely the autoclave and the Resin Transfer moulding (RTM). The canopy was assumed to be made of a carbon fiber reinforced thermosetting material. Using the models developed the expected environmental and cost benefits by involving the RTM technique have been quantified.

This work deals with the fabrication of an innovative hybrid thermoplastic prepreg by continuous hot forming process. The material, suitable also for Automated Fiber Placement process, is produced through a consolidation of commercial PEEK-Carbon Fiber prepreg sandwiched between two amorphous PEI films. Consolidation is performed by a purpose-designed automated prototype equipment operating on defined pressure and thermal cycles. Then preliminary tests on first trials produced were carried out. These activities have been developed in the frame of the NHYTE project, a Research and Innovation Action funded by the European Union's H2020 framework programme, under Grant Agreement No 723309 NOVOTECH acting as Coordinator presents this paper on behalf of all Partners of the project. The proof of NHYTE project concept is the manufacturing of a fastener free and high performing fuselage portion demonstrator.

In this investigation, the fatigue behaviour of a ductile cast iron with high content of silicon and molybdenum, was experimentally characterized by performing isothermal low cycle fatigue (LCF) tests as well as out-of-phase thermomechanical fatigue (OPTMF) tests within the temperature range RT – 500 °C. The studied material shows an embrittlement at temperatures nearby 400 °C. A possible explanation for the observed lifetime reduction is intergranular embrittlement (IE). A mechanism based lifetime model is proposed for assessing the lifetime. The model is based on the assumption that the crack advance per cycle is correlated with the cyclic crack tip opening displacement (ΔCTOD) attributed to the crack tip blunting caused by accumulation of plastic and creep deformations ahead of the crack tip. Intergranular embrittlement is accounted for by introducing a temperature and strain rate dependent prefactor in the crack growth law, which only acts in a certain temperature range. The model is calibrated for a GJS material and successfully applied to predict the lifetime of this material when undergoing isothermal and non-isothermal mechanical loadings. A probabilistic interpretation of the scatter of the investigated material is presented in conjunction with the random nature of the initial defect size distribution.