Identification of damage based on frequency response function (FRF) data

Mechanical joints, particularly fasteners such as bolted joints have a complex non-linear behaviour. The non-linearity might emerge from the material, geometry or by the contacts in the joints. However, damage to a structure can be happened either their connections or the material of components. The effect of damage can change the dynamic properties of the structure such as natural frequencies and mode shapes and structural performance and can cause premature failure to structure. This paper presents a damage detection method using a vibration based damage detection method based on the frequency response function (FRF) data. A combination of numerical model and physical bolted jointed structure of damaged and undamaged structure will be investigated. The validation is employed to detect the presence of damage in the structure based on the frequency response function (FRF) data from the parameter values used in the benchmark model and damaged model. The comparisons of the undamaged and damaged structure of the FRF have revealed the damaged structure was shifted from the undamaged structure. The effect of the FRF between undamaged and damaged structure is clearly affected by the reduction of stiffness for the damaged structure.