Optimal Sensor Placement Based on Substructure Sensitivity

Optimal sensor placement is key issues of structures health monitoring (SHM). In study of sensor placement, the main achievement focus on optimal criterions of sensor locations based on modal test, while optimal criterions of sensor locations based on damage identification, optimal method of sensor locations and optimal sensor number should be investigated further. In this study, a novel optimal sensor placement strategy based on sensitivity is proposed. Optimal sensor placement based on sensitivity analysis is an alternation method to consider damage identification. The basic idea of the proposed methodology is that influence range of different damage parameters is different. First, damage sensitivities in every element based on modal parameters are calculated. Then the elements that are sensitive to damage are selected. According to the detection of damage sensitivity in these elements, minimums number can be found by sensitivity. At last, the elements that are not selected are considered as not sensitive to modal parameters and would be placed the strain sensors. Numerical simulation of a three-dimensional truss structure is implemented to evaluate the minimum sensor number of different damage parameters according to the above methods. Moreover, damage location can be detected under single-damage situation and the element with most severe damage can be identified in multi-damage case using the proposed sensor placement.