Damage detection in beams by roughness analysis

摘要

A new damage detection technique using the roughness profile of structural mode shape is developed in this study. In this method, the spatially distributed signal (e.g., displacements or mode shapes) of a damaged structure is treated as an engineering surface. Irregularity of the surface induced by damage in beam-type structure is then treated as the roughness of the surface. A simple algorithm is developed to extract the roughness profile from the surface. The location and severity of damage is then determined by a sudden change on the roughness profile. This method is then applied to the mode shapes of cracked and delaminated beams obtained analytically, from which the damage location and size are determined successfully. As verifications, the proposed method is further applied on the experimentally measured curvature mode shapes to detect damage in carbon/epoxy composite beams. The successful detection of crack and delamination damage in the composite beams demonstrates that the new technique developed in this study can be used efficiently and effectively in damage identification and health monitoring of beam-type structures.