On the evaluation of the flexibility parameters in edge cracked beams

In this paper an approach that is able to derive the flexibility parameters in beams with an edge crack based on the strain energy density theory is presented. The method takes into account that the crack in a beam does not propagate in a collinear manner, but due to the presence of the mixed mode, it changes its direction. This allows a description of the phenomenon of the propagation of the crack similar to the experimental evidence. The crack is assumed to be vertical before the loading, then it runs in the direction of the minimum of the strain energy density. Then, the crack is supposed to follow the direction of the principal tensile stress in the section. Comparisons are made to the evaluation of the strain energy density in the case of incorrect collinear propagation of the crack. Preliminary results are presented for different position and initial length of the crack.