Crack Localization in L-Shaped Frames

摘要

This paper introduces a method to detect damages in L-shaped frames. The problem of identifying cracks in such structures arises from the low frequency changes due to damage. In the early stage, cracks are hard to be assessed. We present two distinct parts: the assessment of the dynamic behavior of L-shaped and description of the damage evaluation method. In the first part, the mathematical relations contrived for the natural frequencies and mode shapes respectively curvatures are introduced. Afterward, the distribution of the modal energy is found and associated with effects produced by a crack with a given depth in different locations. Findings are used to identify the crack location and severity. Accurate frequency evaluation, a crucial aspect since low frequency changes are expected, was made by employing an algorithm developed by the authors. The damage assessment method with the integrated frequency evaluation algorithm is employed to evaluate the health of an L-framed structure.