User Profile

Since my first acquaintance I was fascinated by the mechanical behaviour of soil and felt the challenge to find an adequate mathematical model to describe it. In doing so I was repelled by the complexity of the theory of plasticity which I felt is inappropriate (i.e. too complicated) to describe soil. I was much more attracted by Rational Mechanics (as stated in the Encyclopedia of Physics article „The Non-Linear Filed Theories of Mechanics“) by Truesdell and Noll. In particular, I was challenged by Nolls idea to express a constitutive law as an evolution equation of the type dT/dt=h(T,D). Instead, the theory of plasticity (which still dominates Soil Mechanics) attempts to manage tensorial relations by introducing scalar functions (surfaces) in the stress space. This may allow impressive simulations but the price is a repelling complexity, that renders constitutive modelling unalluring. As I stated in my article „The misery of constitutive modelling“, this field is still characterised by limited interest and inhibited (due to its complexity) communication. In my new book „A Primer on Theoretical Soil Mechanics“ I show how the mechanical behaviour of soil can be explained by mere reasoning and I also show that a powerful constitutive model, barodesy, can be derived by considering that dry granulates cannot sustain tensile stresses and exhibit fading memory. Admittedly, my first simulations with barodesy did not yield very convincing simulations, until I recently introduced a more general concept of critical density. This allows to introduce unique mathematical formulations for sand and clay. Barodesy is a young frame and many person-years have still to be (hopefully) spent towards calibration and numerical implementation.