ALERT Doctoral School 2021
30^th September to 2^nd October 2021, Aussois, France (or online)

“Constitutive Modelling in Geomaterials“
Coordination: prof. Claudio Tamagnini [CT] and prof. David Mašín [DM]
Lecturers: prof. Ivo Herle [IH], prof. Cristina Jommi [CJ] and prof. Claudio di Prisco [CDP]

Foreword

Irrespectively of fast development of approaches for the analysis and design in geomechanics based on the methods for discontinuum (such as discrete element method), analysis of continua based on mesh or fast developing particle-based meshless methods still represents major means of numerical analysis in geomechanics. At the very core of such an analysis is a constitutive model: mathematical relationship converting the peculiar behaviour of particulate material, governed by the interactions between individual particles, into the behaviour of continua. As such, a properly selected and calibrated constitutive model has a critical effect on the outcomes of geotechnical simulations.

This school aims to introduce the students into the broad field of constitutive modelling of particulate materials with special emphasis on the behaviour of soils: after the introduction consisting of summary of basic features of soil behaviour, they will be introduced into fundamentals of constitutive modelling, followed by more detailed description of various modelling approaches – from the basic elastic and elasto-plastic models to more advanced frameworks of hardening plasticity, bounding surface plasticity, generalised plasticity and hypoplasticity. The second day will be focused on various specific more-advanced topics, such as simulation of small strain stiffness and cyclic loading, modelling of unsaturated soils, meta-stable structure, breakage, thermal effects, chemical effects and time and rate dependence, including formulation of finite-deformation plasticity and macroelement modelling. The last day is devoted to steps needed for adoption of models in numerical analysis tools, namely to their implementation in finite element codes. Finally, in practical hands-on sessions, students will train calibration using real experimental data themselves, using both manual and automatic freely-available calibration tools.

Day 1

• Basic features of soil behaviour and soil testing [CJ]
• Fundamentals of constitutive modelling for soils [IH]
• The theory of plasticity in constitutive modelling of rate-independent soils [CT]
• Hypoplasticity and other incrementally non-linear modelling approaches [DM]

Day 2

• Modelling non-linearity, small-strain stiffness and cyclic loading [DM]
• General overview on modelling the coupled behaviour of unsaturated soils [SJ]
• Meta-stable structure, breakage and thermal effects [DM]
• Time and rate dependence [CDP]
• Finite deformation plasticity [CT]

Day 3

• Numerical implementation of constitutive models [CT]
• Macroelement modelling [CDP, Luca Flessati]