ON MODAL ANALYSIS OF PHASE-FIELD FRACTURE MODELS

In this work, the modal response of a phase-field model of a damaged structure is performed and the influence of various phase-field model parameters on the dynamic response is analysed. Instead of analysing hypothetical cracks, here the crack geometries of the damaged body are predicted by a quasi-static crack propagation simulation by means of an adaptive phase-field method, performed prior to the modal analyses. The modal analyses are performed with respect to the damaged configurations obtained during the fracture simulations. The natural frequencies and corresponding mode shapes of a plate modelled as a tree-dimensional body with a crack has been inspected. Various modifications of the phase field fracture model are used in the modal analysis. The influence of element size and length scale are also studied. From the results, the recommendations for performing the modal analysis of phase-field models are drawn.