Abstract: Structural damage identification is critical to the reliability evaluation of structures. Now damage identification method based on parameters of structural model is one of the research hotspots. Subspace Rotation Algorithm introduced in this paper belongs to the damage identification method based on parameters of structural model. Subspace Rotation Algorithm is based on finite element method of structures,use the matrix transform method and separates the damage location and damage extent problems and is computationally inexpensive. Subspace Rotation Algorithm is used to detect damage of an actual bridge in this paper and practice testifies that Subspace Rotation Algorithm only needs the first order frequency and shape mode to identify the main damage location and damage extent of the actual bridge so that it is simple in calculation and feasible.

Key words: damage identification, Subspace Rotation Algorithm, bridge