𝙿𝚘𝚛𝚘𝚞𝚜𝙻𝚊𝚋 v1.1: a modular finite element framework for simulation of fractured porous media

Abstract. Numerical modeling of fractured porous media requires the combined treatment of coupled processes, nonlinear geomechanical behavior, and strong discontinuities such as fractures and faults. Although several open-source simulators are available for porous-media applications, many are oriented toward large-scale production analyses and rely on mixed discretizations or complex software architectures. This paper presents 𝙿𝚘𝚛𝚘𝚞𝚜𝙻𝚊𝚋, an open-source, object-oriented finite-element framework implemented in MATLAB for transparent formulation development, verification, and rapid prototyping of coupled porous-media models. The current release supports mechanical, single-phase flow, two-phase flow, hydro-mechanical single-phase, and hydro-mechanical two-phase formulations. Nonlinear geomechanical analyses are supported through different constitutive models and solution procedures, including quasi-static continuation schemes and nonlinear transient analyses. Pre-existing fractures and faults can be represented independently of the background mesh using recent embedded finite-element formulations, which simplify model generation by avoiding the need for mesh conformity with discontinuity geometries. The framework stands out for integrating these features within a single FEM-based discretization setting. Furthermore, the code architecture is developed around abstract OOP classes designed to support modularity and extensibility. Verification examples covering the implemented features are presented and compared with reference solutions.