  The phase-field model (PFM) represents the crack geometry in a diffusive way
without introducing sharp discontinuities. This feature enables PFM to
effectively model crack propagation compared with numerical methods based on
discrete crack model, especially for complex crack patterns. Due to the
involvement of \phased field", phase-field method can be essentially treated a
multifield problem even for pure mechanical problem. Therefore, it is supposed
that the implementation of PFM based on a software developer that especially
supports the solution of multifield problems should be more effective, simpler
and more efficient than PFM implemented on a general finite element software.
In this work, the authors aim to devise a simple and efficient implementation
of phase-field model for the modelling of quasi-static and dynamic fracture in
the general purpose commercial software developer, COMSOL Multiphysics. Notably
only the tensile stress induced crack is accounted for crack evolution by using
the decomposition of elastic strain energy. The width of the diffusive crack is
controlled by a length-scale parameter. Equations that govern body motion and
phase-field evolution are written into different modules in COMSOL, which are
then coupled to a whole system to be solved. A staggered scheme is adopted to
solve the coupled system and each module is solved sequentially during one time
step. A number of 2D and 3D examples are tested to investigate the performance
of the present implementation. Our simulations show good agreement with
previous works, indicating the feasibility and validity of the COMSOL
implementation of PFM.
