Assessment of flexural stiffness and load carrying capacity using substructural system

The evaluation philosophy of an existing structure must differ from the design philosophy of a new structure. Many parameters are related to the structural properties and among them, stiffness and boundary conditions are governing factors affecting the resistance of the structure to external loading. However, due to the aging and deterioration of structures, effects of boundary conditions change over time and it becomes intricate to understand their current condition for structural assessment. This study was set out to assess the feasibility of estimating flexural stiffness in beam-like structures using substructural bending rigidity identification (SBI) method when no information about 'as-is' fixity of boundary conditions is available. The results of numerical and experimental analyses showed that the SBI method accurately estimates the flexural stiffness of various beam profiles having unknown boundary conditions. It was found that using estimated stiffness, analytical model can be tuned with updated support fixities and structural and modal characteristics, which are then used for detection of the critical member, worst load effect and evaluation of serviceable load carrying capacity. Findings from this study provided evidence that SBI can be efficiently implemented as a short-term monitoring tool with easy testing setup for in-operation structural integrity assessment of beam-type elements. © 2017 International Society for Structural Health Monitoring of Intelligent Infrastrucure