Nonlinear SEM numerical analyses of dry dense sand specimens under rapid and dynamic loading

Prisco, Claudio Giulio Di; Stupazzini, Marco; Zambelli, C.

doi:10.1002/nag.553

Cited by 22 publications

(9 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Viscoplastic and non‐linear elastic rheologies (e.g. Xu et al 2003; di Prisco et al 2007) are accommodated by the GeoELSE software package (Stupazzini et al 2009; Chaljub et al 2010), and we will consider such non‐linear constitutive relationships in future releases of SPECFEM3D.…”

Section: Discussionmentioning

confidence: 99%

Forward and adjoint simulations of seismic wave propagation on fully unstructured hexahedral meshes

Peter¹,

Komatitsch

Luo³

et al. 2011

Geophysical Journal International

293

184

View full text Add to dashboard Cite

International audienceWe present forward and adjoint spectral-element simulations of coupled acoustic and (an)elastic seismic wave propagation on fully unstructured hexahedral meshes. Simulations benefit from recent advances in hexahedral meshing, load balancing and software optimization. Meshing may be accomplished using a mesh generation tool kit such as CUBIT, and load balancing is facilitated by graph partitioning based on the SCOTCH library. Coupling between fluid and solid regions is incorporated in a straightforward fashion using domain decomposition. Topography, bathymetry and Moho undulations may be readily included in the mesh, and physical dispersion and attenuation associated with anelasticity are accounted for using a series of standard linear solids. Finite-frequency Fr'echet derivatives are calculated using adjoint methods in both fluid and solid domains. The software is benchmarked for a layercake model. We present various examples of fully unstructured meshes, snapshots of wavefields and finite-frequency kernels generated by Version 2.0 'Sesame' of our widely used open source spectral-element package SPECFEM3D

show abstract

Section: Discussionmentioning

confidence: 99%

Forward and adjoint simulations of seismic wave propagation on fully unstructured hexahedral meshes

Peter¹,

Komatitsch

Luo³

et al. 2011

Geophysical Journal International

293

184

View full text Add to dashboard Cite

show abstract

“…Taking Q p into account is particularly important when modelling wave propagation in 2‐D because of the presence of both compressive and Rayleigh waves. This two‐step implementation differs from the ones proposed by other authors, like di Prisco et al (2007) and Stupazzini & Zambelli (2005).…”

Section: Materials Constitutive Models and Wave Propagation Schemementioning

confidence: 77%

2-D <italic>P</italic>–<italic>SV</italic> numerical study of soil–source interaction in a non-linear basin

2012

Geophysical Journal International

View full text Add to dashboard Cite

SUMMARY Basin response depends on the soil properties (site geometry, impedance contrast), on the constitutive model and on the input motion. Numerical modelling is a useful tool to understand the role and the influence of these different parameters governing site effects. In this study, we focus on the 2‐D P–SV seismic wave propagation in a simple asymmetric basin model. We assess the influence of the material constitutive model (elastic, viscoelastic, elastoplastic and viscoelastoplastic) on the wave propagation as well as the importance of the input motion on the development of material non‐linearity. We also show that both viscoelasticity and material non‐linearity strongly modify the ground motion on a broad range of frequencies, yet they have a stronger effect in some particular frequency bands. We advise that realistic simulations should couple both viscoelasticity accounting for energy dissipation at small strains and non‐linear soil behaviour taking into account hysteresis energy dissipation and shear modulus degradation at higher strain levels. In addition, we study the influence of the source frequency content, intensity and complexity on the Fourier and response spectra of horizontal acceleration time histories, and the maximum shear stresses and strains computed within the non‐linear material filling the basin. We show that the complexity and amplitude of the source determines whether damping or reduction of the S‐wave velocity dominates the wave propagation in the non‐linear media. Indeed, for a simple impulsive input the high frequencies are damped whereas for a complex input motion, such a real earthquake, high frequency damping comes together with frequency shift to lower frequency values. For this reason, the use of the source peak ground acceleration (PGA) only is not a good indicator to characterize soil non‐linear effects because of the simultaneous influence of input motion intensity and complexity, impedance contrast, and material strength. However, testing other ground motion indicators is beyond the scope of this paper. At last, we test the importance of dynamic soil properties on the wave propagation and show that shear modulus and damping ratio curves that are relatively close, regarding uncertainties associated to such curves measurements, may lead to notable variations in the acceleration fields. Simulations should take into account this variability to assess the uncertainties on computed ground motion.

show abstract

“…Its performance in presence of strain localisation problems may be fully regularised by coupling viscoplasticity and extension to nonlocality . This can be easily achieved through a nonlocal reformulation of the viscoplastic flow‐rule Equation , as successfully attempted in a few previous works of the authors …”

Section: Constitutive Formulationmentioning

confidence: 99%

“…In this section, the undrained triaxial performance of the proposed model is explored with respect to the undrained triaxial compression (TXU) tests in Table . It is noted that transiting to undrained conditions jeopardises the suitability of the viscous parameters in Tables and , which leads to envisage Φ ( f ) function probably more complex than the assumed exponential form . The different stress paths characterising TXD and TXU tests mobilise different ranges of the Φ ‐ f relationship, whose non‐linearity should be captured for accurate simulations over a wide spectrum of loading conditions.…”

Section: Model Validationmentioning

confidence: 99%

Predictive potential of Perzyna viscoplastic modelling for granular geomaterials

Lazari

Sanavia

Prisco

et al. 2018

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

Summary This paper reappraises Perzyna‐type viscoplasticity for the constitutive modelling of granular geomaterials, with emphasis on the simulation of rate/time effects of different magnitude. An existing elasto‐plastic model for sands is first recast into a Perzyna viscoplastic formulation and then calibrated/validated against laboratory test results on Hostun sand from the literature. Notable model features include (1) enhanced definition of the viscous nucleus function and (2) void ratio dependence of stiffness and viscous parameters, to model the pycnotropic behaviour of granular materials with a single set of parameters, uniquely identified against standard creep and triaxial test results. The comparison between experimental data and numerical simulations points out the predicative capability of the developed model and the complexity of defining a unique viscous nucleus function to capture sand behaviour under different loading/initial/boundary and drainage conditions. It is concluded that the unified viscoplastic simulation of both drained and undrained response is particularly challenging within Perzyna's framework and opens to future research in the area. The discussion presented is relevant, for instance, to the simulation of multiphase strain localisation phenomena, such as those associated to slope stability problems in variably saturated soils.

show abstract

Nonlinear SEM numerical analyses of dry dense sand specimens under rapid and dynamic loading

Cited by 22 publications

References 39 publications

Forward and adjoint simulations of seismic wave propagation on fully unstructured hexahedral meshes

Forward and adjoint simulations of seismic wave propagation on fully unstructured hexahedral meshes

2-D <italic>P</italic>–<italic>SV</italic> numerical study of soil–source interaction in a non-linear basin

Predictive potential of Perzyna viscoplastic modelling for granular geomaterials

Contact Info

Product

Resources

About