Damage detection in instrumented structures without baseline modal parameters

A method to detect damage in structures utilising only dynamic information from a post-damage event is presented. This method, denominated as Baseline Stiffness Method, BSM, may be useful to locate and evaluate the magnitude of structural and nonstructural damage of buildings whose baseline (without damage) state is not known. Extracted mode shapes and vibration frequencies of the instrumented damaged structure are used as data along with the lateral stiffness of the first storey of the system without damage. By means of an iterative process, based on singular value decomposition, it is possible to identify location and severity of damage (degradation of stiffness) utilising an analytical model. Examples of application in instrumented building structures are presented and the advantages of the application of the developed BSM are discussed.