Structural health monitoring for frame structure with semi-rigid joints

This paper presents a method for detecting and locating structural damages in local elements or regions of a structural system by directly utilizing structural vibration measurements. A previously developed damage diagnosis technique is enhanced by including a simplified lumped-mass model, which is equivalent to the complex frame structure. The parameters derived from the simplified lumped-mass model are used in the damage diagnosis algorithm, while the actual dynamic responses measured from the frame structure under seismic excitation are used as the inputs. The dynamic responses measured from different floors can be decoupled by implementing the proposed damage diagnosis algorithm. As a result, damages in the frame structure can be detected and located. Numerical examples of a three-story-one-bay steel frame model and a benchmark-liked four-story-two-bay steel frame model are considered to demonstrate and evaluate the effectiveness of the present method.