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Documents published in Scipedia

• A Particle Finite Element Method (PFEM) for coupled thermal analysis of quasi and fully incompressible flows and fluid-structure interaction

  E. Oñate, A. Franci, J. Puigbó

  (2014). (preprint) Numerical simulation of coupled problems in engineering. S. R. Idelsohn (Eds.), pp. 129-156, Springer

  
  

  Abstract

  We present a Lagrangian formulation for coupled thermal analysis of quasi and fully incompressible flows and fluid-structure interaction (FSI) problems that has excellent mass preservation features. The success of the formulation lays on a residual-based stabilized expression of the mass balance equation obtained using the Finite Calculus (FIC) method. The governing equations are discretized with the FEM using simplicial elements with equal linear interpolation for the velocities, the pressure and the temperature. The merits of the formulation in terms of reduced mass loss and overall accuracy are verified in the solution of 2D and 3D adiabatic and thermally-coupled quasi-incompressible free-surface flow problems using the Particle Finite Element Method (PFEM). Examples include the sloshing of water in a tank and the falling of a water sphere and a cylinder into a tank containing water.

  Abstract
  We present a Lagrangian formulation for coupled thermal analysis of quasi and fully incompressible flows and fluid-structure interaction (FSI) problems that has excellent [...]

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• PFEM formulation for thermo-coupled FSI analysis. Application to nuclear core melt accident

  A. Franci, E. Oñate, J. Puigbó, M. Chiumenti

  Comput. Methods Appl. Mech. Engrg., (2017). Vol. 325, pp. 711-732

  
  

  Abstract

  The aim of this paper is to present a Lagrangian formulation for thermo-coupled fluid–structure interaction (FSI) problems and to show its applicability to the simulation of hypothetical scenarios of a nuclear core melt accident. During this emergency situation, an extremely hot and radioactive lava-like material, the corium, is generated by the melting of the fuel assembly. The corium may induce collapse of the nuclear reactor devices and, in the worst case, breach the reactor containment and escape into the environment. This work shows the capabilities of the proposed formulation to reproduce the structural failure mechanisms induced by the corium that may occur during a meltdown scenario. For this purpose, a monolithic method for FSI problems, the so-called Unified formulation, is here enhanced in order to account for the thermal field and to model phase change phenomena with the Particle Finite Element Method (PFEM). Several numerical examples are presented. First, the convergence of the thermo-coupled method and phase change algorithm is shown for two academic problems. Then, two complex simulations of hypothetical nuclear meltdown situations are studied in 2D as in 3D.

  Abstract
  The aim of this paper is to present a Lagrangian formulation for thermo-coupled fluid–structure interaction (FSI) problems and to show its applicability [...]

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• Advances in the particle finite element method (PFEM) for solving coupled problems in engineering

  E. Oñate, S. Idelsohn, M. Celigueta, R. Rossi, J. Marti, J. Puigbó, P. Ryzhakov, B. Suárez

  (2010). Research Report, Nº PI347

  
  

  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.

  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 [...]

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• Modeling of ground excavation with the particle finite-element method

  J. Puigbó, E. Oñate, B. Suarez

  Journal of Engineering Mechanics (2010). Vol. 136 (4), pp. 455-463

  
  

  Abstract

  An excavation process is a nonlinear dynamic problem that includes geometrical, material, and contact nonlinearities. The simulation of ground excavation has to face contact interaction in a changing geometry composed by several solid domains. The particle finite-element method (PFEM) is based on a Lagrangian description for modeling the motion of a continuum medium. The PFEM is particularly suitable for modeling a fluid motion with free surfaces. The application of the PFEM in ground excavation includes the use of the remeshing process, α-shape concepts for detecting the domain boundary, contact mechanics laws, material constitutive models, and surface wear models. Everything is correctly matched to quantify the excavation and the corresponding damage caused to the ground. The erosion and wear parameters of the soil/rock material govern the evolution of the excavation process. The preliminary results presented in this paper show that the PFEM it is a very suitable tool for the simulation of ground excavation processes.

  Abstract
  An excavation process is a nonlinear dynamic problem that includes geometrical, material, and contact nonlinearities. The simulation of ground excavation has to face contact [...]

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• The Double Hierarchy Method. A parallel 3D contact method for the interaction of spherical particles with rigid FE boundaries using the DEM

  M. Santasusana, J. Irazábal, E. Oñate, J. Puigbó

  Comp. Part. Mech (2016). Vol. 3, pp. 407-428

  
  

  Abstract

  In this work, we present a new methodology for the treatment of the contact interaction between rigid boundaries and spherical discrete elements (DE). Rigid body parts are present in most of large-scale simulations. The surfaces of the rigid parts are commonly meshed with a finite element-like (FE) discretization. The contact detection and calculation between those DE and the discretized boundaries is not straightforward and has been addressed by different approaches. The algorithm presented in this paper considers the contact of the DEs with the geometric primitives of a FE mesh, i.e. facet, edge or vertex. To do so, the original hierarchical method presented by Horner et al. (J Eng Mech 127(10):1027–1032, 2001) is extended with a new insight leading to a robust, fast and accurate 3D contact algorithm which is fully parallelizable. The implementation of the method has been developed in order to deal ideally with triangles and quadrilaterals. If the boundaries are discretized with another type of geometries, the method can be easily extended to higher order planar convex polyhedra. A detailed description of the procedure followed to treat a wide range of cases is presented. The description of the developed algorithm and its validation is verified with several practical examples. The parallelization capabilities and the obtained performance are presented with the study of an industrial application example.

  Abstract
  In this work, we present a new methodology for the treatment of the contact interaction between rigid boundaries and spherical discrete elements (DE). Rigid body parts are [...]

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• Modelling of tunnelling processes and rock cutting tool wear with the particle finite element method

  J. Puigbó, E. Oñate, B. Suarez

  Computational Mechanics (2013). Vol. 52 (3), pp. 607-629

  
  

  Abstract

  Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are growing, and so safety and security demands do. New engineering tools are needed to perform a safer planning and design. This work presents the advances in the particle finite element method (PFEM) for the modelling and the analysis of tunneling processes including the wear of the cutting tools. The PFEM has its foundation on the Lagrangian description of the motion of a continuum built from a set of particles with known physical properties. The method uses a remeshing process combined with the alpha-shape technique to detect the contacting surfaces and a finite element method for the mechanical computations. A contact procedure has been developed for the PFEM which is combined with a constitutive model for predicting the excavation front and the wear of cutting tools. The material parameters govern the coupling of frictional contact and wear between the interacting domains at the excavation front. The PFEM allows predicting several parameters which are relevant for estimating the performance of a tunnelling boring machine such as wear in the cutting tools, the pressure distribution on the face of the boring machine and the vibrations produced in the machinery and the adjacent soil/rock. The final aim is to help in the design of the excavating tools and in the planning of the tunnelling operations. The applications presented show that the PFEM is a promising technique for the analysis of tunnelling problems.

  Abstract
  Underground construction involves all sort of challenges in analysis, design, project and execution phases. The dimension of tunnels and their structural requirements are [...]

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• Velocity‐based formulations for standard and quasi‐incompressible hypoelastic‐plastic solids

  A. Franci, E. Oñate, J. Puigbó

  Int. J. Numer. Meth. Engng. (2016). Vol. 107 (11), pp. 970-990

  
  

  Abstract

  We present three velocity‐based updated Lagrangian formulations for standard and quasi‐incompressible hypoelastic‐plastic solids. Three low‐order finite elements are derived and tested for non‐linear solid mechanics problems. The so‐called V‐element is based on a standard velocity approach, while a mixed velocity–pressure formulation is used for the VP and the VPS elements. The two‐field problem is solved via a two‐step Gauss–Seidel partitioned iterative scheme. First, the momentum equations are solved in terms of velocity increments, as for the V‐element. Then, the constitutive relation for the pressure is solved using the updated velocities obtained at the previous step. For the VPS‐element, the formulation is stabilized using the finite calculus method in order to solve problems involving quasi‐incompressible materials. All the solid elements are validated by solving two‐dimensional and three‐dimensional benchmark problems in statics as in dynamics.

  Abstract
  We present three velocity‐based updated Lagrangian formulations for standard and quasi‐incompressible hypoelastic‐plastic solids. Three low‐order finite elements are [...]

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• Lagrangian formulation for finite element analysis of quasi-incompressible fluids with reduced mass losses

  E. Oñate, A. Franci, J. Puigbó

  Int. J. for Numerical Methods in Fluids (2014). Vol. 74 pp. 699-731 Vol. 74 pp. 699-731 (preprint)

  
  

  Abstract

  We present a Lagrangian formulation for finite element analysis of quasi-incompressible fluids that has excellent mass preservation features. The success of the formulation lays on a new residual-based stabilized expression of the mass balance equation obtained using the Finite Calculus (FIC) method. The governing equations are discretized with the FEM using simplicial elements with equal linear interpolation for the velocities and the pressure. The merits of the formulation in terms of reduced mass loss and overall accuracy are verified in the solution of 2D and 3D quasi-incompressible free-surface flow problems using the Particle Finite Element Method (PFEM, www.cimne.com/pfem). Examples include the sloshing of water in a tank, the collapse of one and two water columns in rectangular and prismatic tanks and the falling of a water sphere into a cylindrical tank containing water. Copyright c 0000 John Wiley & Sons, Ltd.

  Abstract
  We present a Lagrangian formulation for finite element analysis of quasi-incompressible fluids that has excellent mass preservation features. The success of the formulation [...]

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• Advances in the DEM and coupled DEM and FEM techniques in non linear solid mechanics

  E. Oñate, F. Zarate, M. Celigueta, J. González, J. Miquel, J. Puigbó, F. Arrufat, S. Latorre, M. Santasusana

  Eugenio Oñate's Research Reports (2019).

  
  

  Abstract

  In this chapter we present recent advances in the Discrete Element Method (DEM) and in the coupling of the DEM with the Finite Element Method (FEM) for solving a variety of problems in non linear solid mechanics involving damage, plasticity and multifracture situations.

  Abstract
  In this chapter we present recent advances in the Discrete Element Method (DEM) and in the coupling of the DEM with the Finite Element Method (FEM) for solving a variety of [...]

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• A Particle Finite Element Method (PFEM) for analysis of industrial forming processes

  E. Oñate, A. Franci, J. Puigbó

  Computational Mechanics (2014). Vol. 54 pp. 85-107 Vol. 54 pp. 85-107

  
  

  Abstract

  We present a generalized Lagrangian formulation for analysis of industrial forming processes involving thermally coupled interactions between deformable continua. The governing equations for the deformable bodies are written in a unified manner that holds both for fluids and solids. The success of the formulation lays on a residual-based expression of the mass conservation equation obtained using the Finite Calculus (FIC) method that provides the necessary stability for quasi/fully incompressible situations. The governing equations are discretized with the FEM via a mixed formulation using simplicial elements with equal linear interpolation for the velocities, the pressure and the temperature. The merits of the formulation are demonstrated in the solution of 2D and 3D thermally-coupled forming processes using the Particle Finite Element Method (PFEM).

  Abstract
  We present a generalized Lagrangian formulation for analysis of industrial forming processes involving thermally coupled interactions between deformable continua. The governing [...]

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Articles (Documents not available in Scipedia)

• Generation of segmental chips in metal cutting modeled with the PFEM

  JMR Prieto, JM Carbonell, JC Cante, J Oliver, P Jonsén

  Computational Mechanics, 1-17, 2017

• Continuous chip formation in metal cutting processes using the Particle Finite Element Method (PFEM)

  JM Rodríguez, JM Carbonell, JC Cante, J Oliver

  International Journal of Solids and Structures 120, 81-102, 2017

• PFEM formulation for thermo-coupled FSI analysis. Application to nuclear core melt accident

  A Franci, E Oñate, JM Carbonell, M Chiumenti

  Computer Methods in Applied Mechanics and Engineering 325, 711-732, 2017

• Performance of mixed formulations for the particle finite element method in soil mechanics problems

  L Monforte, JM Carbonell, M Arroyo, A Gens

  Computational Particle Mechanics 4 (3), 269-284, 2017

• Damage analysis of masonry structures subjected to rockfalls

  O Mavrouli, PG Giannopoulos, JM Carbonell, C Syrmakezis

  Landslides 14 (3), 891-904, 2017

• Numerical simulation of undrained insertion problems in geotechnical engineering with the Particle Finite Element Method (PFEM)

  L Monforte, M Arroyo, JM Carbonell, A Gens

  Computers and Geotechnics 82, 144-156, 2017

• Simulation of the cone penetration test: discrete and continuum approaches

  A Gens Solé, M Arroyo Alvarez de Toledo, J Butlanska, L Monforte Vila, ...

  Geotechnical and geophysical site characterisation 5: Proceedings of the …, 2016

• Simulation of the cone penetration test: discrete and continuum approaches

  A Gens, M Arroyo, J Butlanska, JM Carbonell, M Ciantia, L Monforte, ...

  Aust. Geomech 51 (4), 169-182, 2016

• Velocity‐based formulations for standard and quasi‐incompressible hypoelastic‐plastic solids

  A Franci, E Oñate, JM Carbonell

  International Journal for Numerical Methods in Engineering 107 (11), 970-990, 2016

• The Double Hierarchy Method. A parallel 3D contact method for the interaction of spherical particles with rigid FE boundaries using the DEM

  M Santasusana, J Irazábal, E Oñate, JM Carbonell

  Computational Particle Mechanics 3 (3), 407-428, 2016

• The particle finite element method (PFEM) in thermo‐mechanical problems

  JM Rodriguez, JM Carbonell, JC Cante, J Oliver

  International Journal for Numerical Methods in Engineering 107 (9), 733-785, 2016

• Numerical simulation of penetration problems in geotechnical engineering with the particle finite element method (PFEM)

  L Monforte Vila, JM Carbonell Puigbó, M Arroyo Alvarez de Toledo, ...

  Proceedings of the IV International Conference on Particle-Based Methods …, 2015

• Explicit finite deformation stress integration of the elasto-plastic constitutive equations

  L Monforte, M Arroyo, A Gens, JM Carbonell

  Computer Methods and Advances in Geomechanics, 267-272, 2015

• On the effect of the bulk tangent matrix in partitioned solution schemes for nearly incompressible fluids

  A Franci, E Oñate, JM Carbonell

  International Journal for Numerical Methods in Engineering 102 (3-4), 257-277, 2015

• Evaluation of multilayer pavement viscoelastic properties from falling weight deflectometer using neural networks

  JM Gonzalez, JM Carbonell, W van Bijsterveld

  Materials and Infrastructures 1, 211-225, 2014

• A particle finite element method (PFEM) for coupled thermal analysis of quasi and fully incompressible flows and fluid-structure interaction problems

  E Oñate, A Franci, JM Carbonell

  Numerical Simulations of Coupled Problems in Engineering, 129-156, 2014

• On the effect of the tangent bulk stiffness matrix in the analysis of free surface Lagrangian flows using PFEM

  A Franci, E Oñate, JM Carbonell

  Research Report CIMNE PI402, 2013

• Modelling of tunnelling processes and rock cutting tool wear with the particle finite element method

  JM Carbonell, E Oñate, B Suárez

  Computational Mechanics 52 (3), 607-629, 2013

• Advances in the particle finite element method (PFEM) for solving coupled problems in engineering

  E Oñate, SR Idelsohn, MA Celigueta, R Rossi, J Marti, JM Carbonell, ...

  Particle-Based Methods, 1-49, 2011

• Análisis numérico de los fenómenos hidrodinámicos en escolleras con aplicaciones a presas de materiales sueltos

  RJ Hernández, E Oñate, SR Idelsohn, MA Celigüeta, R Rossi, J Marti, ...

  Universitat Politècnica de Catalunya. Escola Tècnica Superior d'Enginyers de …, 2010

• Modeling of surface wear by the particle finite element method: application to tunneling processes

  JM Carbonell Puigbó, B Suárez Arroyo, E Oñate Ibáñez de Navarra

  Computational Plasticity X-Fundamentals and Applications, 1-4, 2009