Browsing by Keyword "Modelization"
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Item 3D computational simulation of calcium leaching in cement matrices(2014-10-01) Gaitero, J. J.; Dolado, J. S.; Neuen, C.; Heber, F.; Koenders, E. A.B.; Tecnalia Research & Innovation; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNCalcium leaching is a degradation process consisting in progressive dissolution of the cement paste by migration of calcium atoms to the aggressive solution. It is therefore, a complex phenomenon involving several phases and dissolution and diffusion processes simultaneously. Along this work, a new computational scheme for the simulation of the degradation process in three dimensions was developed and tested. The toolkit was used to simulate accelerated calcium leaching by a 6M ammonium nitrate solution in cement matrices. The obtained outputs were the three dimensional representation of the matrix and the physicochemical properties of individual phases as a consequence of the degradation process. This not only makes it possible to study the evolution of such properties as a function of time but also as a function of the position within the matrix. The obtained results are in good agreement with experimental values of the elastic modulus in degraded and undegraded samples.Item On the Improvements of a Cable-Driven Parallel Robot for Achieving Additive Manufacturing for Construction(Springer International Publishing, 2017-07-06) Izard, Jean-Baptiste; Dubor, Alexandre; Hervé, Pierre-Elie; Cabay, Edouard; Culla, David; Rodriguez, Mariola; Barrado, Mikel; Bruckmann, Tobias; Gosselin, Clement; Cardou, Philippe; Pott, Andreas; Tecnalia Research & Innovation; ROBOTICA_AUTOMA; MAQUINAS; SGGeneralization of additive manufacturing has led to consider this technological solution for more and more challenging use cases. Porting this technology to construction industry is a major step to overcome. Most of the recent research deal with materials, construction and extrusion techniques. Positioning of the extruder or material handler is mostly carried out by standard anthropomorphic robots or large-scale gantries. Cable-driven parallel robots (CDPR) can be an efficient alternative to these positioning solutions, being capable of automated motions in six degrees of freedom and easily relocated. The combination of the Cogiro CDPR (Tecnalia, LIRMM-CNRS, 2010) with the extruder and material of the Pylos project (IAAC, 2013), open the opportunity to a 3D printing machine with a workspace of 13.6 × 9.4 × 3.3 m. Two prints, with different patterns, have been achieved with the Pylos extruder mounted on Cogiro, drawing a wire of material of 11 m in width and 3 mm in height: the first spanning 3.5 m in length, the second, reaching a height of 0.86 m. The motivation of this paper is to give an insight to the necessary technical implementations on a CDPR for dealing with additive manufacturing process relevant for construction, in particular acute modelling of the cable and its extension under load, and to showcase the experimental prints carried out by the authors.