It is noted that the overall crack path (in the figure above) is not necessarily the shortest one with respect to the application of a dynamic load. Depending on the application, an actual crack path may be shorter than the one shown. This is why it is necessary to produce a crack path with PLAXIS to obtain the shortest path.
In general, if the interface is load-transferring, the actual crack path depends on the rigidity of the material. The element-to-soil interaction will influence the crack path which in turn will influence the resulting crack length. The crack path will be influenced by the following factors:
The model depicted in the figure below illustrates the modelled geometry and the associated crack path for the application of a dynamic load in the y-direction. The comment just before the figure highlights the chosen crack path for the application of the dynamic load. Please note that, depending on the loading scenario, the crack path can vary from the one shown, including the presence of additional elements which are not visible on the figure.
When generating the crack path, always keep in mind the condition concerning the modelled element-to-soil interaction, that is, only the elements which are considered in the chosen design of the element-to-soil interface with respect to the soil-to-element interaction are taken into account.
The plugins package contains a module that is devoted to the dynamic simulation of cracks such as the one shown above. We recall that the module can be used either in 2D or in 3D, in which case the simulation must be carried out by using the corresponding module.
The formulation of the crack model used by PLAXIS 2D is the one used by MD-GEOGRID for the formulation of geotextiles, where the crack deflection is also implemented with explicit elements in the crack. A complete description of the code is given in Destrade, \"MODFLOW-GEOGRID\", 1999.
The set of equations governing the crack movement, or more specifically the crack deflection, is based on a methodology similar to the one used by the MD-GEOGRID crack module. It is based on defining the gradient of the crack opening displacement with respect to the crack advancement direction. 7211a4ac4a