A New Method of Obtaining Modal Sensitivity for Damage Location in Beam Structure

In beam structure, damage detection is important to the safety during its usage. The non-destructive method (NDM) based on based on variation of natural frequencies of structure are powerful and commonly employed. However, the modal sensitivity of structure, which is the key information used in NDM algorithms is usually obtained with numerical calculation, which may bring inaccuracy due to the error in numerical calculation and the difference between the real structure and the numerical model. In response to the problems mentioned above, this paper proposes a new method to obtain modal sensitivity of beam structure, which is totally based on experimental data rather than numerical simulation. In this new method, a mass is attached to the testing beam to obtain the modal sensitivity. After the modal sensitivity is obtained, an artificial defection is made to the testing beam. With the modal sensitivity achieved, the location the defection is successfully determined with relatively small error, which confirms the feasibility of this new method.