Experimental and numerical investigations on defect location detection of multi-damage steel beams using advanced damage location vector approach

Damage location vector (DLV) method is a model-based structural health monitoring approach that needs the frequency response–function response of the structure. A review of the literature indicates that although the DLV method accurately identifies the damage location in the single-damage structures, it does not work properly for the multi-damage. Accordingly, the aim of this research is to advance the DLV approach to increase its accuracy to detect the damage locations and severities in the multi-damage structures. In this regard, experimental and numerical studies were performed on the two-fixed ends steel beam having multiple damages with different intensities. During laboratory tests, the vibration response of steel beam specimens with multiple defects stimulated by hammer impact was measured. Different sensor locations were considered in the tests. A finite-element model of the steel beam was developed to calculate the dynamic response of undamaged beam under impact loading. Based on the fundamentals of hypothesis testing and data fusion, a threshold was derived to advance the DLV approach to detect the multiple damages. Moreover, the effect of sensor position on the performance of the DLV approach was investigated. The proposed method was also applied to a long-span box-shaped bridge to investigate its accuracy and efficiency for detecting damages in realistic complex structures. Moreover, the results obtained from the advanced DLV method were compared with other conventional methods, considering the effect of noise and different damage scenarios. The findings reveal that the advanced DLV approach proposed in this study accurately detects the defect locations and severities in the structures having multiple damages.