NumPy-based Calibration of Basic Hypoplastic Constitutive Models

Abstract

Constitutive modeling of soils is a crucial topic in geotechnics. Several constitutive models for soils can be found in material libraries of open-source or commercial geotechnical software packages, and these models can be based on various theories. Hypoplasticity as a relatively young theory is an alternative to elastoplasticity and consistently attracts new researchers. Contrary to elastoplasticity, hypoplasticity does not involve a priori defined yield surface, flow rule and plastic potential and arises from a simple tensorial function of the rate type. An exhaustive review of literature, however, points to the fact that for the calibration of these models, commercial symbolic mathematics software is mostly referred to and a calibration procedure based upon an open-source software which any individuals can easily make use of is missing. Therefore, an explicit procedure for calibration making use of NumPy, which is the main package for scientific computing with Python, following a concise summary for the theory of hypoplasticity is established. By doing so, it is expected to draw attention to take advantage of open-source packages that almost the majority of the scientific community utilizes increasingly.