http://hdl.handle.net/2117/4001 Sat, 18 May 2013 19:32:58 GMT 2013-05-18T19:32:58Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19274 Title: Modelling viscoelastic behaviour of carbón nanotube-reinforced thermo-plastics Authors: Otero Gruer, Fermín Enrique; Oller Martínez, Sergio Horacio; Martínez García, Javier; Salomón, Ramón Omar Abstract: Carbon nanotubes (CNTs), since their discovery by Lijima (S. Lijima, Nature, 354:56-58 (1991)), are considered a new generation of reinforcement. Their "nano" size structure makes them potentially free of defects, which provides them with excellent physical properties. There are two main nanotube types: single wall nanotubes (SWCNTs), which are made of a single wall tube; and multiwall nanotubes (MWCNTs), which consist in several concentric walls, one inside the other. A key factor for the reinforcement efficiency in a composite it is the interface bonding between the CNTs and the matrix. This work presents a new constitutive model to predict the mechanical performance of composites made of a thermo-plastic matrix reinforced with CNTs. The model takes into account explicitly the mechanical contribution of the interface between the matrix and the CNTs (F. Otero et. al., Comp Structures, 94:2920-2930 (2012)). The constitutive model is based in the mixing theory, which obtains the composite performance from the response of each constituent component, each one simulated with its own constitutive law. The model has been implemented into an in-house FEM code: PLCd. As an application example, this code is used to predict the mechanical properties of a straight beam with different material configurations. In this case, a viscoelastic constitutive model is proposed for the polymeric matrix. The viscous response within the elastic range of the materials is studied. This response shows a high capacity of energy dissipation in composites reinforced with MWCNTs. Thu, 16 May 2013 08:54:11 GMT http://hdl.handle.net/2117/19274 2013-05-16T08:54:11Z Otero Gruer, Fermín Enrique; Oller Martínez, Sergio Horacio; Martínez García, Javier; Salomón, Ramón Omar no Carbon nanotubes (CNTs), since their discovery by Lijima (S. Lijima, Nature, 354:56-58 (1991)), are considered a new generation of reinforcement. Their "nano" size structure makes them potentially free of defects, which provides them with excellent physical properties. There are two main nanotube types: single wall nanotubes (SWCNTs), which are made of a single wall tube; and multiwall nanotubes (MWCNTs), which consist in several concentric walls, one inside the other. A key factor for the reinforcement efficiency in a composite it is the interface bonding between the CNTs and the matrix. This work presents a new constitutive model to predict the mechanical performance of composites made of a thermo-plastic matrix reinforced with CNTs. The model takes into account explicitly the mechanical contribution of the interface between the matrix and the CNTs (F. Otero et. al., Comp Structures, 94:2920-2930 (2012)). The constitutive model is based in the mixing theory, which obtains the composite performance from the response of each constituent component, each one simulated with its own constitutive law. The model has been implemented into an in-house FEM code: PLCd. As an application example, this code is used to predict the mechanical properties of a straight beam with different material configurations. In this case, a viscoelastic constitutive model is proposed for the polymeric matrix. The viscous response within the elastic range of the materials is studied. This response shows a high capacity of energy dissipation in composites reinforced with MWCNTs. http://hdl.handle.net/2117/19251 Title: The particle finite element method (PFEM): an effective numerical technique for solving marine, naval and harbour engineering problems Authors: Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Suárez Arroyo, Benjamín Abstract: We present some developments in the Particle Finite Element Method (PFEM) for the solution of complex coupled problems in marine, naval and harbour engineering involving fluid-soil-structure interaction (FSSI). The PFEM uses an updated Lagrangian description to model the motion of nodes (particles) in a continuum domain containing fluid, soil/rock and structures subdomains. A mesh connects the nodes defining the discretized domain where the governing equations for each of the constituent materials are solved with the FEM. The stabilization for dealing with an incompressibility material is introduced via the finite calculus (FIC) method. An incremental iterative scheme for solving the non linear transient FSSI problem is described. The procedure to model frictional contact conditions and material erosion at fluid-solid and solid-solid interfaces is described. We present examples of application of the PFEM to solve FSSI problems in marine, naval and harbour engineering such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the sinking of ships and the collision of a ship with ice blocks. Wed, 15 May 2013 13:36:16 GMT http://hdl.handle.net/2117/19251 2013-05-15T13:36:16Z Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Suárez Arroyo, Benjamín no We present some developments in the Particle Finite Element Method (PFEM) for the solution of complex coupled problems in marine, naval and harbour engineering involving fluid-soil-structure interaction (FSSI). The PFEM uses an updated Lagrangian description to model the motion of nodes (particles) in a continuum domain containing fluid, soil/rock and structures subdomains. A mesh connects the nodes defining the discretized domain where the governing equations for each of the constituent materials are solved with the FEM. The stabilization for dealing with an incompressibility material is introduced via the finite calculus (FIC) method. An incremental iterative scheme for solving the non linear transient FSSI problem is described. The procedure to model frictional contact conditions and material erosion at fluid-solid and solid-solid interfaces is described. We present examples of application of the PFEM to solve FSSI problems in marine, naval and harbour engineering such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the sinking of ships and the collision of a ship with ice blocks. http://hdl.handle.net/2117/19121 Title: Shock-free aerofoil/wing design optimisation via morphing technique: leading and trailing edge deformation Authors: Lee, D.S.; Srinivas, K.; Periaux, Jacques; Oñate Ibáñez de Navarra, Eugenio Abstract: The paper investigates the drag reduction of aerofoils and wings using a morphing technique which consists of deforming the leading and trailing edges. It is treated as an optimisation procedure using Evolutionary Algorithms. For the purpose, an in house code - Multi-Objective Genetic Algorithm (MOGA) under High Performance Computing (HPC) environment is used. An Euler code with viscous corrections is used to compute the flow. Baseline design is that of RAE5243. Two test cases are considered; the first one considers a morphing aerofoil/wing design via trailing edge deformation (TED) while the second test uses both leading and trailing edge deformations (LTED) to minimise the total drag. Numerical results show that applying morphing technique on existing aerofoil/wing significantly reduces transonic total drag and improves lift on drag (L/D) value when compared to the baseline design. Tue, 07 May 2013 14:53:27 GMT http://hdl.handle.net/2117/19121 2013-05-07T14:53:27Z Lee, D.S.; Srinivas, K.; Periaux, Jacques; Oñate Ibáñez de Navarra, Eugenio no The paper investigates the drag reduction of aerofoils and wings using a morphing technique which consists of deforming the leading and trailing edges. It is treated as an optimisation procedure using Evolutionary Algorithms. For the purpose, an in house code - Multi-Objective Genetic Algorithm (MOGA) under High Performance Computing (HPC) environment is used. An Euler code with viscous corrections is used to compute the flow. Baseline design is that of RAE5243. Two test cases are considered; the first one considers a morphing aerofoil/wing design via trailing edge deformation (TED) while the second test uses both leading and trailing edge deformations (LTED) to minimise the total drag. Numerical results show that applying morphing technique on existing aerofoil/wing significantly reduces transonic total drag and improves lift on drag (L/D) value when compared to the baseline design. http://hdl.handle.net/2117/19120 Title: A strategy case to facilitate the technology transfer between universities-enterprise Authors: Sánchez Romero, Montserrat; Gil Espert, Lluís; Segura Vicente, Sonia Tue, 07 May 2013 13:35:49 GMT http://hdl.handle.net/2117/19120 2013-05-07T13:35:49Z Sánchez Romero, Montserrat; Gil Espert, Lluís; Segura Vicente, Sonia no http://hdl.handle.net/2117/18923 Title: Tensile tests of basalt FRP rebars using mechanical anchorages Authors: Neagoe, Catalin Andrei; Gil Espert, Lluís Abstract: In the current report are analyzed the experimental results of initial tensile tests of Basalt FRP (BFRP) rebars provided by VSL. The investigation was conducted on the 19th of February 2013, in the laboratory of CER LITEM. Objectives of the study: to determine the tensile strengths of 6 mm and 8 mm basalt FRP rebars, and to determine what type of test setup and anchorage system is best suited for future tensile tests of BFRP bars. Mon, 22 Apr 2013 13:23:46 GMT http://hdl.handle.net/2117/18923 2013-04-22T13:23:46Z Neagoe, Catalin Andrei; Gil Espert, Lluís no In the current report are analyzed the experimental results of initial tensile tests of Basalt FRP (BFRP) rebars provided by VSL. The investigation was conducted on the 19th of February 2013, in the laboratory of CER LITEM. Objectives of the study: to determine the tensile strengths of 6 mm and 8 mm basalt FRP rebars, and to determine what type of test setup and anchorage system is best suited for future tensile tests of BFRP bars. http://hdl.handle.net/2117/18922 Title: Tensile tests of basalt FRP rebars using chemical anchorages Authors: Neagoe, Catalin Andrei; Gil Espert, Lluís Abstract: In the current report are analyzed the experimental results of initial tensile tests of Basalt FRP (BFRP) rebars provided by VSL. The investigation was conducted in the laboratory of CER LITEM. Objectives of the study: to determine the tensile strengths of 6 mm and 8 mm basalt FRP rebars, and to determine what type of test setup and anchorage system is best suited for future tensile tests of BFRP bars. Mon, 22 Apr 2013 13:19:46 GMT http://hdl.handle.net/2117/18922 2013-04-22T13:19:46Z Neagoe, Catalin Andrei; Gil Espert, Lluís no In the current report are analyzed the experimental results of initial tensile tests of Basalt FRP (BFRP) rebars provided by VSL. The investigation was conducted in the laboratory of CER LITEM. Objectives of the study: to determine the tensile strengths of 6 mm and 8 mm basalt FRP rebars, and to determine what type of test setup and anchorage system is best suited for future tensile tests of BFRP bars. http://hdl.handle.net/2117/18921 Title: Tensile tests of basalt FRP rebars using steel wedges Authors: Neagoe, Catalin Andrei; Gil Espert, Lluís Abstract: In the current report are analyzed the experimental results of several tensile tests of Basalt FRP (BFRP) rebars provided by VSL, anchored with steel wedges. The investigation was conducted in the laboratory of CER LITEM Objectives of the study: to determine the failure modes and ultimate tensile stresses of 6 mm and 8 mm Basalt FRP rebars anchored with two different steel wedge systems; and to compare the anchoring efficiency of the wedge systems. Mon, 22 Apr 2013 13:15:56 GMT http://hdl.handle.net/2117/18921 2013-04-22T13:15:56Z Neagoe, Catalin Andrei; Gil Espert, Lluís no In the current report are analyzed the experimental results of several tensile tests of Basalt FRP (BFRP) rebars provided by VSL, anchored with steel wedges. The investigation was conducted in the laboratory of CER LITEM Objectives of the study: to determine the failure modes and ultimate tensile stresses of 6 mm and 8 mm Basalt FRP rebars anchored with two different steel wedge systems; and to compare the anchoring efficiency of the wedge systems. http://hdl.handle.net/2117/18920 Title: Tensile tests of Basalt FRP rebars using steel wedges with aluminum sleeves Authors: Neagoe, Catalin Andrei; Gil Espert, Lluís Abstract: In the current report are analyzed the experimental results of several tensile tests of Basalt FRP (BFRP) rebars provided by VSL, anchored with steel wedges with aluminum sleeves. The investigation was conducted in the laboratory of CER LITEM from the Department of Strength of Materials and Structural Engineering of Universitat Politècnica de Catalunya – BarcelonaTech. Objective of the study: to determine the failure modes and ultimate tensile stresses of 6 mm and 8 mm Basalt FRP rebars, anchored with steel wedge systems with aluminum sleeves. Mon, 22 Apr 2013 13:09:17 GMT http://hdl.handle.net/2117/18920 2013-04-22T13:09:17Z Neagoe, Catalin Andrei; Gil Espert, Lluís no In the current report are analyzed the experimental results of several tensile tests of Basalt FRP (BFRP) rebars provided by VSL, anchored with steel wedges with aluminum sleeves. The investigation was conducted in the laboratory of CER LITEM from the Department of Strength of Materials and Structural Engineering of Universitat Politècnica de Catalunya – BarcelonaTech. Objective of the study: to determine the failure modes and ultimate tensile stresses of 6 mm and 8 mm Basalt FRP rebars, anchored with steel wedge systems with aluminum sleeves. http://hdl.handle.net/2117/18871 Title: Self-assessment exercises in continuum mechanics with autonomous learning Authors: Marcé Nogué, Jordi; Gil Espert, Lluís; Pérez Martínez, Marco Antonio; Sánchez Romero, Montserrat Thu, 18 Apr 2013 13:59:09 GMT http://hdl.handle.net/2117/18871 2013-04-18T13:59:09Z Marcé Nogué, Jordi; Gil Espert, Lluís; Pérez Martínez, Marco Antonio; Sánchez Romero, Montserrat no http://hdl.handle.net/2117/18813 Title: Adaptive finite element simulation of incompressible flows by hybrid continuous-discontinuous Galerkin formulations Authors: Badia Rodríguez, Santiago I.; Baiges Aznar, Joan Abstract: In this work we design hybrid continuous-discontinuous finite element spaces that permit discontinuities on non-matching element interfaces of non-conforming meshes. Then, we develop an equal-order stabilized finite element formulation for incompressible flows over these hybrid spaces, which combines the element interior stabilization of SUPGtype continuous Galerkin formulations and the jump stabilization of discontinuous Galerkin formulations. Optimal stability and convergence results are obtained. For the adaptive setting, we use an standard error estimator and marking strategy. Numerical experiments show the optimal accuracy of the hybrid algorithm both for uniformly and adaptively refined non-conforming meshes. The outcome of this work is a finite element formulation that can naturally be used on nonconforming meshes, as discontinuous Galerkin formulations, while keeping the much lower CPU cost of continuous Galerkin formulations. Tue, 16 Apr 2013 12:27:53 GMT http://hdl.handle.net/2117/18813 2013-04-16T12:27:53Z Badia Rodríguez, Santiago I.; Baiges Aznar, Joan no Incompressible flows, adaptive refinement, continuous-discontinuous Galerkin, equal-order interpolation, stabilization In this work we design hybrid continuous-discontinuous finite element spaces that permit discontinuities on non-matching element interfaces of non-conforming meshes. Then, we develop an equal-order stabilized finite element formulation for incompressible flows over these hybrid spaces, which combines the element interior stabilization of SUPGtype continuous Galerkin formulations and the jump stabilization of discontinuous Galerkin formulations. Optimal stability and convergence results are obtained. For the adaptive setting, we use an standard error estimator and marking strategy. Numerical experiments show the optimal accuracy of the hybrid algorithm both for uniformly and adaptively refined non-conforming meshes. The outcome of this work is a finite element formulation that can naturally be used on nonconforming meshes, as discontinuous Galerkin formulations, while keeping the much lower CPU cost of continuous Galerkin formulations. http://hdl.handle.net/2117/18804 Title: Un caso práctico de meta-evaluación docente: el manual de evaluación de la Universidad Politécnica de Cataluña Authors: García-Berro Montilla, Enrique; de la Vega, Ricardo; Gemma, Amblàs; Martínez, Erica; Laura, Campeny; Bugeda Castelltort, Gabriel; Roca, Santiago Abstract: La Universidad Politécnica de Cataluña ha sido pionera en la introducción de un modelo de eva- luación docente plenamente adaptado a las exigencias del Espacio Europeo de Enseñanza Supe- rior. Además, su sistema de evaluación de la actividad docente del profesorado ha sido homologa- do por la AQU y ANECA. Dicho modelo de evaluación docente se basa en las más recientes di- rectrices europeas y tiene como fundamento diversos indicadores indirectos. Este modelo se ha em- pleado para evaluar la docencia del profesorado en cinco convocatorias. Durante este periodo de tiempo se ha acumulado una información valiosísima que permite obtener datos agregados no só- lo de la calidad de los docentes sino, también, de diversas características inherentes al proceso de evaluación, así como de la bondad de los indicadores empleados. En este artículo se presentan es- tos datos y se muestra un conjunto de datos agregados que permiten estimar la bondad y fiabilidad del proceso de evaluación, así como su aceptación por el profesorado evaluado. Mon, 15 Apr 2013 15:46:10 GMT http://hdl.handle.net/2117/18804 2013-04-15T15:46:10Z García-Berro Montilla, Enrique; de la Vega, Ricardo; Gemma, Amblàs; Martínez, Erica; Laura, Campeny; Bugeda Castelltort, Gabriel; Roca, Santiago no La Universidad Politécnica de Cataluña ha sido pionera en la introducción de un modelo de eva- luación docente plenamente adaptado a las exigencias del Espacio Europeo de Enseñanza Supe- rior. Además, su sistema de evaluación de la actividad docente del profesorado ha sido homologa- do por la AQU y ANECA. Dicho modelo de evaluación docente se basa en las más recientes di- rectrices europeas y tiene como fundamento diversos indicadores indirectos. Este modelo se ha em- pleado para evaluar la docencia del profesorado en cinco convocatorias. Durante este periodo de tiempo se ha acumulado una información valiosísima que permite obtener datos agregados no só- lo de la calidad de los docentes sino, también, de diversas características inherentes al proceso de evaluación, así como de la bondad de los indicadores empleados. En este artículo se presentan es- tos datos y se muestra un conjunto de datos agregados que permiten estimar la bondad y fiabilidad del proceso de evaluación, así como su aceptación por el profesorado evaluado. http://hdl.handle.net/2117/18315 Title: Feasibility study of strengthening unreinforced masonry structures with shotcrete and textile Authors: Aranha, Chrysl A.; Bernat Masó, Ernest; Gil Espert, Lluís; Escrig Pérez, Christian Thu, 14 Mar 2013 17:08:42 GMT http://hdl.handle.net/2117/18315 2013-03-14T17:08:42Z Aranha, Chrysl A.; Bernat Masó, Ernest; Gil Espert, Lluís; Escrig Pérez, Christian no http://hdl.handle.net/2117/18313 Title: Advanced computational intelligence system for inverse aeronautical design optimisation Authors: Lee, D.S.; Periaux, Jacques; Oñate Ibáñez de Navarra, Eugenio; Gonzalez, L. Abstract: Computational Intelligence Systems (CIS) is one of advanced softwares. CIS has been important position for solving single-objective / reverse / inverse and multi-objective design problems in engineering. The paper hybridise a CIS for optimisation with the concept of Nash-Equilibrium as an optimisation pre-conditioner to accelerate the optimisation process. The hybridised CIS (Hybrid Intelligence System) coupled to the Finite Element Analysis (FEA) tool and one type of Computer Aided Design (CAD) system; GiD is applied to solve an inverse engineering design problem; reconstruction of High Lift Systems (HLS). Numerical results obtained by the hybridised CIS are compared to the results obtained by the riginal CIS. The benefits of using the concept of Nash-Equilibrium are clearly demonstrated in terms of solution accuracy and optimisation efficiency. Thu, 14 Mar 2013 16:58:27 GMT http://hdl.handle.net/2117/18313 2013-03-14T16:58:27Z Lee, D.S.; Periaux, Jacques; Oñate Ibáñez de Navarra, Eugenio; Gonzalez, L. no Computational Intelligence System, Reverse Engineering, Reconstruction/Inverse Design, Evolutionary Optimisation, Game-Strategies, Nash-Equilibrium Computational Intelligence Systems (CIS) is one of advanced softwares. CIS has been important position for solving single-objective / reverse / inverse and multi-objective design problems in engineering. The paper hybridise a CIS for optimisation with the concept of Nash-Equilibrium as an optimisation pre-conditioner to accelerate the optimisation process. The hybridised CIS (Hybrid Intelligence System) coupled to the Finite Element Analysis (FEA) tool and one type of Computer Aided Design (CAD) system; GiD is applied to solve an inverse engineering design problem; reconstruction of High Lift Systems (HLS). Numerical results obtained by the hybridised CIS are compared to the results obtained by the riginal CIS. The benefits of using the concept of Nash-Equilibrium are clearly demonstrated in terms of solution accuracy and optimisation efficiency. http://hdl.handle.net/2117/18261 Title: The structural performance of arches made of few vossoirs with dry-joints Authors: Bernat Masó, Ernest; Gil Espert, Lluís; Marcé Nogué, Jordi Wed, 13 Mar 2013 14:24:00 GMT http://hdl.handle.net/2117/18261 2013-03-13T14:24:00Z Bernat Masó, Ernest; Gil Espert, Lluís; Marcé Nogué, Jordi no http://hdl.handle.net/2117/18259 Title: Design, tuning and evaluation of parallel multilevel ILU preconditioners Authors: Aliaga, José Ignacio; Bollhoefer, Matthias; Martín Huertas, Alberto Francisco; Quintana-Ortí, Enrique Salvador Abstract: In this paper, we present a parallel multilevel ILU preconditioner implemented with OpenMP. We employ METIS partitioning algorithms to decompose the computation into concurrent tasks, which are then scheduled to threads. Concretely, we combine decompositions which obtain significantly more tasks than processors, and the use of dynamic scheduling strategies in order to reduce the thread’s idle time, which it is shown to be the main source of overhead in our parallel algorithm. Experimental results on a shared-memory platform consisting of 16 processors report remarkable performance for our approach. Wed, 13 Mar 2013 13:15:59 GMT http://hdl.handle.net/2117/18259 2013-03-13T13:15:59Z Aliaga, José Ignacio; Bollhoefer, Matthias; Martín Huertas, Alberto Francisco; Quintana-Ortí, Enrique Salvador no In this paper, we present a parallel multilevel ILU preconditioner implemented with OpenMP. We employ METIS partitioning algorithms to decompose the computation into concurrent tasks, which are then scheduled to threads. Concretely, we combine decompositions which obtain significantly more tasks than processors, and the use of dynamic scheduling strategies in order to reduce the thread’s idle time, which it is shown to be the main source of overhead in our parallel algorithm. Experimental results on a shared-memory platform consisting of 16 processors report remarkable performance for our approach.