Study On Symptom-based Reliability And Symptom Sensitivity Analysis For Latticed Structures Under Atmospheric Exposure

Due to the obvious insufficient of usual reliability assessment method of existing structures, how to use the information acquired from structural health monitoring to the structural state assessment of existing structures is a topic which is worth studying with the development of structural health monitoring. As the connection of structural health monitoring technique and structural state assessment method of existing structures, symptom-based reliability analysis is capable of updating the assessment of existing structures and making a prediction of the remaining useful life of existing structures with the real-time information acquired from structural health monitoring.In this paper, the symptom-based approach is analyzed and usual structural symptom models are enumerated. A new approach for the structural state assessment and the prediction of the remaining useful life of existing structures is also presented by modified structural symptom models using the deviation of symptom.The finite element model of deteriorating latticed structures under atmospheric exposure is built and reliability curve is obtained by reliability analysis based on different symptoms like stress, fundamental period and deflection.Parameter sensitivity analysis theory is introduced and the introduction of dimensionless parameter sensitivity analysis method makes the system sensitive evaluation of the different physical parameters established on uniform standards. By measuring the degradation degree of structures based on the decline of symptom reliability, with structure without degradation being reference state, the sensitivity of three different parameters of latticed structures under atmospheric exposure is analyzed. The sensitivity analysis of parameters like stress, fundamental period and deflection showed that latticed structures is most sensitive to changes in the structural natural periods and the growth fastest relative to other symptoms of growth as the main symptom, should focus on monitoring.