http://hdl.handle.net/2117/4006 2013-05-26T04:41:57Z 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. 2013-05-15T13:36:16Z http://hdl.handle.net/2117/17371 Title: Shaped metal deposition processes Authors: Agelet de Saracibar Bosch, Carlos; Lundbäck, Andreas; Chiumenti, Michèle; Cervera Ruiz, Miguel Abstract: The shaped metal deposition (SMD) process is a novel manufacturing technology which is similar to the multi-pass welding used for building features such as lugs and flanges on components. This innovative technique is of great interest due to the possibility of employing standard welding equipment without the need for extensive new investment. 2013-01-15T14:23:01Z http://hdl.handle.net/2117/17136 Title: The particle finite element method: an effective numerical technique for solving fluid-soil-structure interaction problems Authors: Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Salazar, F.; Suárez Arroyo, Benjamín 2012-12-17T15:25:53Z http://hdl.handle.net/2117/16271 Title: The particle finite element method for multi-fluid flows Authors: Idelsohn Barg, Sergio Rodolfo; Mier Torrecilla, Mónica de; Marti, Julio; Oñate Ibáñez de Navarra, Eugenio Abstract: This paper presents the Particle Finite Element Method (PFEM) and its application to multi-fluid flows. Key features of the method are the use of a Lagrangian description to model the motion of the fluid particles (nodes) and that all the information is associated to the particles. A mesh connects the nodes defining the discretized domain where the governing equations, expressed in an integral form, are solved as in the standard FEM.We have extended the method to problems involving several different fluids with the aim of exploiting the fact that Lagrangian methods are specially well suited for tracking any kind of interfaces. 2012-07-17T13:45:10Z http://hdl.handle.net/2117/16101 Title: A practial approach to study of fire resistance of a steel structure with open built-up members and columns Authors: Marimón Carvajal, Federico; Jiménez, Albert; Ferrer Ballester, Miquel 2012-06-19T11:01:05Z http://hdl.handle.net/2117/15968 Title: El aprendizaje de competencias: un nuevo reto en la educación superior Authors: Pérez Gracia, María de la Vega 2012-06-05T10:49:29Z http://hdl.handle.net/2117/15636 Title: Shock control bump design optimization on natural laminar aerofoil Authors: Lee, D.S.; Periaux, Jacques; Srinivas, K.; Gonzalez, L.F.; Qin, N.; Oñate Ibáñez de Navarra, Eugenio Abstract: The paper investigates Shock Control Bumps (SCB) on a Natural Laminar Flow (NLF) aerofoil; RAE 5243 for Active Flow Control (AFC). A SCB approach is used to decelerate supersonic flow on the suction/pressure sides of transonic aerofoil that leads delaying shock occurrence or weakening of shock strength. Such an AFC technique reduces signi cantly the total drag at tran- sonic speeds. This paper considers the SCB shape design optimisation at two boundary layer transition positions (0% and 45%) using an Euler software coupled with viscous boundary layer e ects and robust Evolutionary Algorithms (EAs). The optimisation method is based on a canonical Evolution Strategy (ES) algorithm and incorporates the concepts of hierarchical topology and parallel asynchronous evaluation of candidate solution. Two test cases are considered with numerical experiments; the rst test deals with a transition point occurring at the leading edge and the transition point is xed at 45% of wing chord in the second test. Numerical results are presented and it is demonstrated that an optimal SCB design can be found to signi cantly reduce transonic wave drag and improves lift on drag (L=D) value when compared to the baseline aerofoil design. 2012-03-21T14:57:23Z http://hdl.handle.net/2117/14164 Title: A general stabilized formulation for incompressible fluid flow using finite calculus and the finite element method Authors: Oñate Ibáñez de Navarra, Eugenio; García Espinosa, Julio; Bugeda Castelltort, Gabriel; Idelsohn Barg, Sergio Rodolfo Abstract: We present a general formulation for incompressible fluid flow analysis using the finite element method (FEM). The necessary stabilization for dealing with convective effects and the incompressibility condition are introduced via the so called finite calculus (FIC) method. The extension of the standard eulerian form of the equations to an arbitrary lagrangian-eulerian (ALE) frame adequate for treating fluid-structure interaction problems is presented. The fully lagrangian form is also discussed. Details of an effective mesh updating procedure are presented together with a method for dealing with free surface effects of importance for ship hydrodynamic analysis and many other fluid flow problems. Examples of application of the eulerian, the ALE and the fully lagrangian flow descriptions are presented. 2011-12-02T18:34:58Z http://hdl.handle.net/2117/14163 Title: Advances in the particle finite element method (PFEM) for solving coupled problems in engineering Authors: Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Rossi, Riccardo; Marti, J.; Carbonell Puigbó, Josep Maria; Ryzhakov, Pavel; Suárez Arroyo, Benjamín Abstract: We present some developments in the formulation of the Particle Finite Element Method (PFEM) for analysis of complex coupled problems on fluid and solid mechanics in engineering accounting for fluid-structure interaction and coupled thermal effects, material degradation and surface wear. The PFEM uses an updated Lagrangian description to model the motion of nodes (particles) in both the fluid and the structure domains. Nodes are viewed as material points which can freely move and even separate from the main analysis domain representing, for instance, the effect of water drops. A mesh connects the nodes defining the discretized domain where the governing equations are solved, as in the standard FEM. The necessary stabilization for dealing with the incompressibility of the fluid is introduced via the finite calculus (FIC) method. An incremental iterative scheme for the solution of the non linear transient coupled fluid-structure problem is described. The procedure for modelling frictional contact conditions at fluid-solid and solid-solid interfaces via mesh generation are described. A simple algorithm to treat soil erosion in fluid beds is presented. An straight forward extension of the PFEM to model excavation processes and wear of rock cutting tools is described. Examples of application of the PFEM to solve a wide number of coupled problems in engineering such as the effect of large waves on breakwaters and bridges, the large motions of floating and submerged bodies, bed erosion in open channel flows, the wear of rock cutting tools during excavation and tunneling and the melting, dripping and burning of polymers in fire situations are presented. 2011-12-02T17:55:31Z http://hdl.handle.net/2117/9483 Title: Escenarios de impacto sísmico Authors: Pujades Beneit, Lluís; Barbat Barbat, Horia Alejandro 2010-10-06T18:38:49Z http://hdl.handle.net/2117/9481 Title: Computational simulation of the seismic response of buildings with energy dissipating devices Authors: Barbat Barbat, Horia Alejandro; Mata Almonacid, Pablo; Oller Martínez, Sergio Horacio; Vielma, Juan Carlos Abstract: In this work, the nonlinear dynamic response of RC buildings with energy dissipating devices is studied using advanced computational techniques. A fully geometric and constitutive nonlinear model is used for describing the dynamic behavior of structures. The equations of motion are expressed in terms of cross sectional forces and strains and its weak form is solved using the displacement based finite element method. A suitable version of Newmark’s scheme is used in updating the kinematics variables in a classical Newton type iterative scheme. Material points of the cross section are assumed to be composed of several simple materials with their own constitutive laws. The mixing theory is used to treat the resulting composite. A specific finite element based on the beam theory is proposed for the dissipators including constitutive relations. Finally, several numerical tests are carried out to validate the proposed model. 2010-10-06T18:26:53Z http://hdl.handle.net/2117/9480 Title: Neuro-fuzzy assessment of building damage and safety after an earthquake Authors: Carreño Tibaduiza, Martha Liliana; Cardona, Omar. D.; Barbat Barbat, Horia Alejandro Abstract: This chapter describes the algorithmic basis of a computational intelligence technique, based on a neuro-jilzzy system, developed with the objective ofassisting nonexpert professionals ofbuilding construction to evaluate the damage andsafety ofbuildings after strong earthquakes, facilitating decision-making during the emergency response phase on their habitability and reparability. A hybrid neuro-jilzzy system is proposed, based on a special three-layer feed-forward artificial neural network and fuzzy rule bases. The inputs to the system are jilzzy sets, taking into account that the damage levels ofthe structural components are linguistic variables, defined by means ofqualifications such as slight, moderate or severe, which are very appropriate to handle subjective and incomplete information. The chapter is a contribution to the understanding ofhow soft computing applications, such as artificial neural networks and fuzzy sets, can be used to complex and urgent processes of engineering decision-making, like the building occupancy after a seismic disaster. 2010-10-06T18:20:33Z http://hdl.handle.net/2117/8434 Title: Avoiding instabilities caused by added mass effects in fluid-structure interaction problems Authors: Idelsohn Barg, Sergio Rodolfo; Pin, Facundo del; Rossi, Riccardo Abstract: The main goal of this paper is to present a new strategy to avoid the unstable behavior caused by added mass effects in approaches the involve pressure segregation or staggered techniques in incompressible flows. We will start by partitioning a monolithic fluid-structure interaction scheme using a static condensation of the velocity terms. We will analyse each term and propouse some approximations to the original problem that will greately simplify the solution step without detriment of the fluid-structure interaction stability. Finally we will present some numerical results with eveident added mass effects to eveluate the effectiveness of our technique. 2010-07-27T16:52:53Z