COLLECTIONS

Documents published in Scipedia

• A discontinuity-capturing crosswind-dissipation for the finite element solution of the convection-diffusion equation

  R. Codina

  Comput. Methods Appl. Mech. Engrg., (1993). Vol. 110 (3-4), pp. 325-342

  
  

  Abstract

  To avoid the local oscillations that still remain using the streamline-upwind/Petrov-Galerkin formulation for the scalar convection-diffusion equation, the introduction of a nonlinear crosswind dissipation is proposed. It is shown that the method is less overdiffusive than other discontinuity-capturing techniques and has better numerical behavior. The design of the crosswind diffusion is based on the study of the discrete maximum principle for some simple cases.

  Abstract
  To avoid the local oscillations that still remain using the streamline-upwind/Petrov-Galerkin formulation for the scalar convection-diffusion equation, the introduction of [...]

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• Stability analysis of the forward Euler scheme for the convection‐diffusion equation using the SUPG formulation in space

  R. Codina

  Int. J. Numer. Meth. Engng. (1993). Vol. 36, 1445-1464

  
  

  Abstract

  The stability and accuracy of the forward Euler scheme for the semidiscrete problem arising from the space discretization of the convection‐diffusion equation using the SUPG formulation are analysed. Both linear and quadratic finite elements are considered. The stability limits are derived for the one‐dimensional problem and a heuristic criterion is proposed for the multidimensional equation. Some numerical experiments are conducted in order to assess the performance of different finite elements

  Abstract
  The stability and accuracy of the forward Euler scheme for the semidiscrete problem arising from the space discretization of the convection‐diffusion equation using the [...]

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• An iterative penalty method for the finite element solution of the stationary Navier-Stokes equations

  R. Codina

  Comput. Methods Appl. Mech. Engrg., (1993). Vol. 110 (3-4), pp. 237-262

  
  

  Abstract

  The objective of this paper is to analyse an iterative procedure for the finite element solution of the Stokes and Navier-Stokes stationary problems. For the latter case, the usual condition on the viscosity and the data that ensures uniqueness is assumed. The method is based on the iterative imposition of the incompressibility condition via penalization. Theoretical and numerical results show that this constraint can be approximated iteratively within the same iterative loop used to deal with the nonlinear term of the equations. Two particular iterative schemes are analysed, namely those based on the Picard and Newton-Raphson algorithms.

  Abstract
  The objective of this paper is to analyse an iterative procedure for the finite element solution of the Stokes and Navier-Stokes stationary problems. For the latter case, [...]

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• Simulación numérica de problemas termomecánicos

  C. Agelet de Saracibar

  Monograph CIMNE (2003). M75

  
  

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• Numerical Methods

  C. Agelet de Saracibar, R. Boman, P. Bussetta, J. Cajas, M. Cervera, M. Chiumenti, A. Coll, P. Dadvand, J. Hernández, G. Houzeaux, M. Riera, J. Ponthot

  (2016). C. Agelet de Saracibar (Ed.) in G.J. Schmitz, U. Prahl (Eds.), Handbook of Software Solutions for ICME, Chapter 7 Wiley, 632 pages, pp. 487-532

  
  

  Abstract

  As one of the results of an ambitious project, this handbook provides a well-structured directory of globally available software tools in the area of Integrated Computational Materials Engineering (ICME).  The compilation covers models, software tools, and numerical methods allowing describing electronic, atomistic, and mesoscopic phenomena, which in their combination determine the microstructure and the properties of materials. It reaches out to simulations of component manufacture comprising primary shaping, forming, joining, coating, heat treatment, and machining processes. Models and tools addressing the in-service behavior like fatigue, corrosion, and eventually recycling complete the compilation.  An introductory overview is provided for each of these different modelling areas highlighting the relevant phenomena and also discussing the current state for the different simulation approaches. A must-have for researchers, application engineers, and simulation software providers seeking a holistic overview about the current state of the art in a huge variety of modelling topics. This handbook equally serves as a reference manual for academic and commercial software developers and providers, for industrial users of simulation software, and for decision makers seeking to optimize their production by simulations. In view of its sound introductions into the different fields of materials physics, materials chemistry, materials engineering and materials processing it also serves as a tutorial for students in the emerging discipline of ICME, which requires a broad view on things and at least a basic education in adjacent fields.

  Abstract
  As one of the results of an ambitious project, this handbook provides a well-structured directory of globally available software tools in the area of Integrated Computational [...]

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• Numerical simulation and visualization of material flow in friction stir welding via particle tracing

  N. Dialami, M. Chiumenti, M. Cervera, C. Agelet de Saracibar, J. Ponthot, P. Bussetta

  (2014). S. Idelsohn (Ed.), Numerical Simulations of Coupled Problems in Engineering, Part III, Chapter 7 Computational Methods, Vol. 33, Springer, pp. 157-169

  
  

  Abstract

  This work deals with the numerical simulation and material flow visualization of Friction Stir Welding (FSW) processes. The 4-th order Runge-Kutta (RK4) integration method is used for the computation of particle trajectories. The particle tracing method is used to study the effect of input process parameters and pin shapes on the weld quality. The results show that the proposed method is suitable for the optimization of the FSW process.

  Abstract
  This work deals with the numerical simulation and material flow visualization of Friction Stir Welding (FSW) processes. The 4-th order Runge-Kutta (RK4) integration method [...]

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• Shaped metal deposition processes

  C. Agelet de Saracibar, A. Lundbäck, M. Chiumenti, M. Cervera

  (2014). R.B. Hetnarski (Ed.), Encyclopedia of Thermal Stresses Springer Dordrecht, Heidelberg, New York, London,, pp. 4346-4355

  
  

  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 [1–7]. This innovative technique is of great interest due to the possibility of employing standard welding equipment without the need for extensive new investment [8, 9]. The numerical simulation of SMD processes has been one of the research topics of great interest over the last years and requires a fully coupled thermo-mechanical formulation, including phase-change phenomena defined in terms of both latent heat release and shrinkage effects [1–6]. It is shown how computational welding mechanics models can be used to model SMD for prediction of temperature evolution, transient, as well as residual stresses and distortions due to the successive welding layers deposited. Material behavior is characterized by a thermo-elasto-viscoplastic constitutive model coupled with a metallurgical model [6]. Two different materials, nickel superalloy 718 [6] and titanium Ti-6Al-4 V 28/5/2014 Shaped Metal Deposition Processes - Springer http://link.springer.com/referenceworkentry/10.1007/978-94-007-2739-7_808/fulltext.html 2/15 [7], are considered in this work. Both heat convection and heat radiation models are introduced to dissipate heat through the boundaries of the component. The in-house-developed coupled thermomechanical finite element (FE) software COMET [10] is used to deal with the numerical simulation, and an ad hoc activation methodology is formulated to simulate the deposition of the different layers of filler material.

  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 [...]

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• Thermo-Mechanical Contact in Casting Analysis

  M. Chiumenti, C. Agelet de Saracibar, M. Cervera

  (2006). J.L. Pérez-Aparicio (Ed.), Practical Applications Using Computational Contact Mechanics TCN, Trento, pp. 107-142, ISBN: 88-95176-01-4

  
  

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• Challenges to be tackled in the computational modeling and numerical simulation of FSW processes

  C. Agelet de Saracibar

  Metals (2019). Vol. 9 (5), pp. 573

  
  

  Abstract

  The computational modeling and numerical simulation of Friction Stir Welding (FSW) processes is an extremely challenging task due to the highly nonlinear and coupled nature of the physical problem and the complex computational issues that need to be properly tackled in the numerical model.

  Abstract
  The computational modeling and numerical simulation of Friction Stir Welding (FSW) processes is an extremely challenging task due to the highly nonlinear and coupled nature [...]

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• Challenges to be tackled in the computational modeling and numerical simulation of FSW processes

  C. Agelet de Saracibar

  Metals (2019). Vol. 9 (5), pp. 573

  
  

  Abstract

  The computational modeling and numerical simulation of Friction Stir Welding (FSW) processes is an extremely challenging task due to the highly nonlinear and coupled nature of the physical problem and the complex computational issues that need to be properly tackled in the numerical model.

  Abstract
  The computational modeling and numerical simulation of Friction Stir Welding (FSW) processes is an extremely challenging task due to the highly nonlinear and coupled nature [...]

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