Study on the applications of different cover methods in numerical manifold method (NMM)

Abstract

Numerical manifold method (NMM) is a powerful unified continuous-discontinuous method due to its dual cover systems and the flexibility of the cover types. In this work, to better solve problems with various discontinuity geometry characteristics by NMM, the finite element method (FEM) mesh and the NMM traditional regular mathematical mesh are employed to construct finite covers for NMM, respectively. Moreover, an independent cover method by which a single physical domain is represented as one manifold element is also introduced. Different types of covers are coupled to simulate the uniaxial loading of mesoscopic concrete models, as well as a rock slope slumping model. The corresponding deformation, fracturing and failure processes are numerically reproduced satisfactorily and consistently by NMM with different combinations of the cover methods. Simulations are also carried out to investigate the important problem of dynamic sliding for discontinua by employing different cover methods in NMM simulations. The results in this work indicate that an appropriate application of the cover methods benefits the reasonable construction of NMM simulation models by avoiding unfavorable extremely small or elongated manifold elements. Meanwhile, the simulation efficiency could be improved due to the reduction of the manifold element number and the contact number at discontinuities.