Damage localization for offshore structures by modal strain energy decomposition method

A newly developed damage localization method applicable to two-dimensional and three-dimensional frame structures is presented. This method is based on decomposing the modal strain energy into two parts, one associated with element´s axial coordinates and the other transverse coordinates. The method requires only a small number of mode shapes identified from damaged and undamaged structures. Numerical studies are conducted based on synthetic data generated from finite element models. This study demonstrates that the newly developed method is capable of localizing damage for template offshore structures no matter of the damage located either at a vertical pile, a horizontal beam or a slanted brace.