Now showing items 1-20 of 34

  • A computational multiscale homogenization framework accounting for inertial effects: application to acoustic metamaterials modelling 

    Roca Cazorla, David; Lloberas Valls, Oriol; Cante Terán, Juan Carlos; Oliver Olivella, Xavier (2018-03)
    Article
    Open Access
    A framework, based on an extended Hill–Mandel principle accounting for inertial effects (Multiscale Virtual Work principle), is developed for application to acoustic problems in the context of metamaterials modelling. The ...
  • A domain decomposition approach to multiscale analysis for structures with softening materials 

    Lloberas Valls, Oriol; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (2009)
    Conference report
    Restricted access - publisher's policy
    In this contribution we present a domain decomposition framework for the multiscale analysis of softening materials. In particular we focus on the finite element tearing and interconnecting (FETI) technique implemented in ...
  • Advanced numerical techniques for modeling tensile crack propagation in gravity dams 

    Dias, I.F.; Oliver Olivella, Xavier; Lemos, J.V.; Lloberas Valls, Oriol (Laboratório Nacional de Engenharia Civil, 2015)
    Conference report
    Open Access
    Cracks propagating deep inside gravity dams can seriously affect their structural safety. Due to the potential catastrophic scenarios associated to the collapse of large concrete dams, it is a fundamental issue to ...
  • Applications of domain decomposition techniques for the multiscale modeling of softening materials 

    Lloberas Valls, Oriol; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (2009)
    Conference report
    Open Access
    In this contribution we describe a methodology for the study of softening brittle materials at different scales of observation. The goal is to account for a higher resolution at those areas that undergo the non-linear ...
  • Computational design of locally resonant acoustic metamaterials 

    Roca Cazorla, David; Yago Llamas, Daniel; Cante Terán, Juan Carlos; Lloberas Valls, Oriol; Oliver Olivella, Xavier (2019-03)
    Article
    Restricted access - publisher's policy
    The so-called Locally Resonant Acoustic Metamaterials (LRAM) are considered for the design of specifically engineered devices capable of stopping waves from propagating in certain frequency regions (bandgaps), this making ...
  • Computational homogenization for multiscale crack modeling: implementational and computational aspects 

    Nguyen, Vinh Phu; Lloberas Valls, Oriol; Sluys, Lambertus J.; Stroeven, Martijn (John Wiley & sons, 2012-01)
    Article
    Open Access
    A computational homogenization procedure for cohesive and adhesive crack modeling of materials with a heterogeneous microstructure has been recently presented in Computer Methods in Applied Mechanics and Engineering (2010, ...
  • Computational material design for acoustic cloaking 

    Méndez, Carlos Alberto; Podestá, J.M.; Lloberas Valls, Oriol; Toro, Sebastian; Huespe, Alfredo Edmundo; Oliver Olivella, Xavier (John Wiley & Sons, 2017-12)
    Article
    Open Access
    A topology optimization technique based on the topological derivative and the level set function is utilized to design/synthesize the micro-structure of a pentamode material for an acoustic cloaking device. The technique ...
  • Concurrent multiscale analysis of heterogeneous materials 

    Lloberas Valls, Oriol; Everdij, Frank P. X.; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (Vienna University of Technology, 2012)
    Conference report
    Restricted access - publisher's policy
    Concurrent multiscale analysis of quasi-brittle heterogeneous materials such as concrete and rock is conducted employing non-overlapping domain decomposition techniques. Initially, a coarse discretization with effective ...
  • Crack path field and strain injection techniques in dynamic fracture simulations 

    Lloberas Valls, Oriol; Huespe, Alfredo Edmundo; Oliver Olivella, Xavier; Dias, I.F. (2016)
    Conference report
    Open Access
    Dynamic fracture phenomena are studied employing low cost computational tools based on Finite Elements with Embedded strong discontinuities (E-FEM). Fracture nucleation and propagation are accounted for through the injection ...
  • Domain decomposition and parallel direct solvers as an adaptive multiscale strategy for damage simulation in materials 

    Everdij, Frank P. X.; Lloberas Valls, Oriol; Simone, Angelo; Rixen, Daniel J.; Sluys, Lambertus J. (Springer, 2016)
    Conference report
    Restricted access - publisher's policy
    Understanding physical phenomena of heterogeneous materials is an ongoing active research field in the structural design of buildings and roads. The failure analysis of quasi-brittle materials such as concrete is a particular ...
  • Educating XXIst century civil engineers in Barcelona 

    Turmo Coderque, José; Estela Carbonell, M. Rosa; Chacón Flores, Rolando Antonio; Gironella Cobos, Xavier; Lloberas Valls, Oriol; Oliver Olivella, Xavier; Poblet-Puig, Jordi; Puigví Burniol, Maria Àngels; Valls del Barrio, Susanna; Díez, Pedro (2017)
    Conference report
    Restricted access - publisher's policy
    The educational programs of Civil Engineering schools have evolved to adapt to changes in society demands and regulations. Specifically, Civil Engineering curricula in Spain was highly impacted by the Bolonia Declaration ...
  • Enhanced domain decomposition techniques for the modeling of softening materials 

    Lloberas Valls, Oriol; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J.; Stroeven, Martijn (2009)
    Conference report
    Restricted access - publisher's policy
    In this study a FETI: Finite Element Tearing and Interconnecting [1] technique is adopted and exploited for the efficient and accurate modeling of softening materials such as concrete and rock. A fie scale analysis in which ...
  • Homogenization-based multiscale crack modelling: from micro-diffusive damage to macro-cracks 

    Nguyen, Vinh Phu; Lloberas Valls, Oriol; Stroeven, Martijn; Sluys, Lambertus J. (2011-02)
    Article
    Open Access
    The existence of a representative volume element (RVE) for a class of quasi-brittle materials having a random heterogeneous microstructure in tensile, shear and mixed mode loading is demonstrated by deriving traction–separation ...
  • Implementation and assessment of a two-scale computational framework for softening materials 

    Lloberas Valls, Oriol (2006)
    External research report
    Open Access
    The objective of this report is to introduce, implement and assess a two-scale FE technique for the mechanical study of heterogeneous quasi-brittle materials. Although the field of multi-scale analysis of structures is ...
  • Modeling tensile crack propagation in concrete gravity dams via crack-path-field and strain injection techniques 

    Dias, I.F.; Oliver Olivella, Xavier; Lemos, J.V.; Lloberas Valls, Oriol (2016-03)
    Article
    Open Access
    This work investigates tensile crack propagation in concrete gravity dams by using some recently developed numerical techniques (crack-path field and strain injection techniques). The work carefully addresses aspects related ...
  • Model Order Reduction in computational multiscale fracture mechanics 

    Caicedo Silva, Manuel Alejandro; Oliver Olivella, Xavier; Huespe, Alfredo Edmundo; Lloberas Valls, Oriol (2016-09)
    Article
    Open Access
    Nowadays, the model order reduction techniques have become an intensive research eld because of the increasing interest in the computational modeling of complex phenomena in multi-physic problems, and its conse- quent ...
  • Multiscale analysis of damage using dual and primal domain decomposition techniques 

    Lloberas Valls, Oriol; Everdij, Frank P. X.; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE), 2014)
    Conference report
    Open Access
    In this contribution, dual and primal domain decomposition techniques are studied for the multiscale analysis of failure in quasi-brittle materials. The multiscale strategy essentially consists in decomposing the structure ...
  • Multiscale analysis of heterogeneous brittle materials using domain decomposition techniques 

    Lloberas Valls, Oriol; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (2010)
    Conference report
    Restricted access - publisher's policy
    In this contribution we present a multiscale framework for the analysis of brittle materials based on domain decomposition approaches. In particular, the FETI (Finite Element Tearing and Interconnecting) [1] method is ...
  • Multi-scale modeling of softening materials 

    Lloberas Valls, Oriol; Simone, Angelo; Sluys, Lambertus J. (International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM), 2008)
    Conference report
    Restricted access - publisher's policy
    This paper presents an assessment of a two-scale framework for the study of softening materials such as concrete. The procedure is based on a hierarchical Finite Element (FE) scheme in which computations are performed both ...
  • Objective multiscale analysis of random heterogeneous materials 

    Lloberas Valls, Oriol; Everdij, Frank P. X.; Rixen, Daniel J.; Simone, Angelo; Sluys, Lambertus J. (2013)
    Conference report
    Open Access
    The multiscale framework presented in [1, 2] is assessed in this contribution for a study of random heterogeneous materials. Results are compared to direct numerical simulations (DNS) and the sensitivity to user-defined ...