a new output-only modal space framework to identify closely-spaced modes and structural mass distribution using blind source separation

In recent years, the advent of output-only methods helps researchers to overcome the difficulties and costs of measuring input-motions during identifying structural systems. blind source separation (bss) is a prominent approach, which is based on output measurements of structure. blind modal identification (bmi) is one of the byproducts of this method for structures when there is lack of information about inputs. in this paper, a new framework introduced toidentify the modal properties of two various synthetic 3-dof structures. the first one is a 3-dof system with relatively well separated natural frequencies and the second one is a 3-dof system with closely-spaced modes.