Journal: Journal of the Mechanics and Physics of Solids

Abbreviation

J. Mech. Phys. Solids

Publisher

Elsevier

Journal Volumes

ISSN

0022-5096
1873-4782

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Publications 1 - 10 of 66
  • On the potential of recurrent neural networks for modeling path dependent plasticity
    Item type: Journal Article
    Gorji, Maysam B.; Mozaffar, Mojtaba; Heidenreich, Julian N.; et al. (2020)
    Journal of the Mechanics and Physics of Solids
  • On the thermodynamic consistency of the equivalence principle in continuum damage mechanics
    Item type: Journal Article
    Keller, A.; Hutter, K. (2011)
    Journal of the Mechanics and Physics of Solids
  • A topology optimisation framework to design test specimens for one-shot identification or discovery of material models
    Item type: Journal Article
    Ghouli, Saeid; Flaschel, Moritz; Kumar, Siddhant; et al. (2025)
    Journal of the Mechanics and Physics of Solids
    The increasing availability of full-field displacement data from imaging techniques in experimental mechanics is determining a gradual shift in the paradigm of material model calibration and discovery, from using several simple-geometry tests towards a few, or even one single test with complicated geometry. The feasibility of such a “one-shot” calibration or discovery heavily relies upon the richness of the measured displacement data, i.e., their ability to probe the space of the state variables and the stress space (whereby the stresses depend on the constitutive law being sought) to an extent sufficient for an accurate and robust calibration or discovery process. The richness of the displacement data is in turn directly governed by the specimen geometry. In this paper, we propose a density-based topology optimisation framework to optimally design the geometry of the target specimen for calibration of an anisotropic elastic material model. To this end, we perform automatic, high-resolution specimen design by maximising the robustness of the solution of the inverse problem, i.e., the identified material parameters, given noisy displacement measurements from digital image correlation. We discuss the choice of the cost function and the design of the topology optimisation framework, and we analyse a range of optimised topologies generated for the identification of isotropic and anisotropic elastic responses.
  • Phase-field modeling of elastic microphase separation
    Item type: Journal Article
    Oudich , Hamza; Carrara, Pietro; De Lorenzis, Laura (2026)
    Journal of the Mechanics and Physics of Solids
    We propose a novel phase-field model to predict elastic microphase separation in polymer gels. To this end, we extend the Cahn-Hilliard free-energy functional to incorporate an elastic strain energy and a coupling term. These contributions are naturally obtained from a derivation that starts from an entropic elastic energy density combined with the assumption of weak compressibility, upon second-order approximation around the swollen state. The resulting terms correspond to those of a poroelastic formulation where the coupling energetic term can be interpreted as the osmotic work of the solvent within the polymer matrix. Additionally, a convolution term is included in the total energy to model non-local forces responsible for coarsening arrest. With analytical derivations in 1D and finite element computations in 2D we show that the mechanical deformation controls the composition of the stable phases, the initial characteristic length and time, the coarsening rates and the arrested characteristic length. Moreover, we demonstrate that the proposed coupling is able to predict the arrest of coarsening at a length scale controlled by the stiffness of the dry polymer. The numerical results show excellent agreement with the experimental evidence in terms of phase-separated morphology and scaling of the characteristic length with the stiffness of the dry polymer.
  • A phase-field model for ferroelectrics with general kinetics, Part I: Model formulation
    Item type: Journal Article
    Guin, Laurent; Kochmann, Dennis M. (2023)
    Journal of the Mechanics and Physics of Solids
    When subjected to electro-mechanical loading, ferroelectrics see their polarization evolve through the nucleation and evolution of domains. Existing mesoscale phase-field models for ferroelectrics are typically based on a gradient-descent law for the evolution of the order parameter. While this implicitly assumes that domain walls evolve with linear kinetics, experiments instead indicate that domain wall kinetics is nonlinear. This, in turn, is an important feature for the modeling of rate-dependent effects in polarization switching. We propose a new multiple-phase-field model for ferroelectrics, which permits domain wall motion with nonlinear kinetics, with applications in other solid–solid phase transformation problems. By means of analytical traveling wave solutions, we characterize the interfacial properties (energy and width) and the interface kinetics of straight domain walls, as furnished by the general kinetics model, and compare them to those of the classical Allen–Cahn model. We show that the proposed model propagates domain walls with arbitrarily chosen nonlinear kinetic relations, which can be tuned to differ for the different types of domain walls in accordance with experimental evidence.
  • A coupled damage-plasticity model for the cyclic behavior of shear-loaded interfaces
    Item type: Journal Article
    Carrara, Pietro; De Lorenzis, Laura (2015)
    Journal of the Mechanics and Physics of Solids
  • Experimental characterization and constitutive modeling of thermoplastic polyurethane under complex uniaxial loading
    Item type: Journal Article
    Reyes, Sergio; Vassiliou, Michalis F.; Konstantinidis, Dimitrios (2024)
    Journal of the Mechanics and Physics of Solids
    This paper presents the testing and constitutive modeling of a Thermoplastic Polyurethane (TPU) compound used in commercial applications. The tested specimens were extracted directly from a TPU sphere used in check valves through water-jet cutting. The tests included tensile and compression tests under complex uniaxial loading protocols to capture different nonlinear phenomena, such as stress softening, hysteresis, relaxation, creep, and rate dependence. The material is modeled assuming a nonlinear elastic equilibrium path that may exhibit stress softening (i.e., Mullins effect), and a hysteretic viscoplastic response that presents rate dependence at three different time scales. To achieve this constitutive behavior, a Parallel Rheological Framework model is used. The nonlinear elastic equilibrium path is modeled using the generalized Yeoh hyperelastic model. The stress softening of the equilibrium path is modeled using the Ogden-Roxburgh damage model on the deviatoric response. The hysteretic viscous response is further split into three viscoplastic chains to represent time dependence at three different time scales in a decoupled way. Each viscoplastic chain is modeled using the Bergstrom-Boyce model with its standard evolution law of the creep strain. The model parameters were found using a stochastic optimization scheme to simultaneously fit all the considered tests. The outstanding agreement between the model and the experimental data across a wide range of loading scenarios provides additional insight into the time-dependent behavior and deformation mechanism of TPUs. Moreover, it shows that the mechanical behavior of these materials can be represented by decoupling the nonlinear viscoplastic behavior in different time scales.
  • Automated discovery of interpretable hyperelastic material models for human brain tissue with EUCLID
    Item type: Journal Article
    Flaschel, Moritz; Yu, Huitian; Reiter, Nina; et al. (2023)
    Journal of the Mechanics and Physics of Solids
    We propose an automated computational algorithm for simultaneous model selection and parameter identification for the hyperelastic mechanical characterization of biological tissue and validate it on experimental data stemming from human brain tissue specimens. Following the motive of the recently proposed computational framework EUCLID (Efficient Unsupervised Constitutive Law Identification and Discovery) and in contrast to conventional parameter calibration methods, we construct an extensive set of candidate hyperelastic models, i.e., a model library including popular models known from the literature, and develop a computational strategy for automatically selecting a model from the library that conforms to the available experimental data while being represented as an interpretable symbolic mathematical expression. This computational strategy comprises sparse regression, i.e., a regression problem that is regularized by a sparsity promoting penalty term that filters out irrelevant models from the model library, and a clustering method for grouping together highly correlated and thus redundant features in the model library. The model selection procedure is driven by data stemming from mechanical tests under different deformation modes, i.e., uniaxial compression/tension and simple torsion. The data is acquired through conventional mechanical tests that deliver labeled one-dimensional data pairs, and thus the method can be interpreted as a supervised counterpart to the originally proposed EUCLID that is informed by full-field displacement data and global reaction forces. The proposed method is verified on synthetical data with artificial noise. In addition, we present for the first time an experimental investigation of the EUCLID framework by validating the proposed method on experimental data acquired through mechanical tests of human brain specimens, proving that the method is capable of discovering hyperelastic models that exhibit both high fitting accuracy to the data as well as concise and thus interpretable mathematical representations.
  • A continuum description of substrate-free dissipative reconfigurable metamaterials
    Item type: Journal Article
    Khajehtourian, Romik; Kochmann, Dennis M. (2021)
    Journal of the Mechanics and Physics of Solids
    Reconfigurable structures have gained importance in soft robotics, for deployable and shape-morphing systems, as well as in programmable metamaterials with controllable static and dynamic properties. The fundamental building block of all such architectures is a structural unit whose tessellation results in multistability, allowing the overall system to switch between two or more equilibrium states. With increasing size and complexity, the description of those systems as discrete structures becomes cumbersome and computationally expensive (especially when considering design exploration and optimization), which is why we here introduce an effective continuum description of substrate-free (ungrounded) dissipative reconfigurable metamaterials. Passing from a discrete network to a continuum (while accounting for viscous effects in the lossy base materials) allows us to efficiently and accurately describe the time-dependent reconfiguration mechanisms. We demonstrate the performance of our approach through several examples of metamaterials and structures made of bistable unit cells in 2D and 3D, which also serve to highlight the versatility and potential of the multistable design approach towards achieving as-designed sequences of motion.
  • Deformation and damage due to drying-induced salt crystallization in porous limestone
    Item type: Journal Article
    Derluyn, Hannelore; Moonen, Peter; Carmeliet, Jan (2013)
    Journal of the Mechanics and Physics of Solids
Publications 1 - 10 of 66