Structural Identification from Operational Modal Analysis: The Case of Steel Structures

Abstract

In the case of old existing structures where the cultural value is very high, structural health analyses and investigations would be better performed without damages or service interruptions. Thus, modal analysis aimed at identifying eigenfrequencies and eigenmodes represents a very effective strategy to identify structural characteristics. In this paper, an innovative strategy to identify structural parameters exploiting the modal information obtained from operational modal analysis is proposed. The importance of the structural modeling in the problem formulation is highlighted. In the case of a simply supported beam, it was possible to assess the beam steel elastic modulus, while in the case of a cantilever beam, some constraint characteristics have been evaluated as well. In the steel frame case, the focus was on the constraint conditions of the structure determining the flexural stiffness of the springs representing the column base constraints. The method performances are promising for applications in larger structures such as bridges and buildings.

Ensuring the Safety of Steel Moment Frames Subjected to Uncertain Impacts

“…These studies are focused on the mechanical characteristics of materials, plastic deformation, and energy dissipation. In [14], modal analysis is used to identify the mechanical characteristics of structures in operation for a certain period of time, namely, structures of historic buildings. This approach can be applied to identify the boundary conditions of structures, including those boundary conditions that are triggered by accidental impacts.…”