As a consequence of the ground motions during near-field earthquakes, stronger design and controlling damages of vital structures should be significantly paid attention. Seismic base isolation system is an effective approach for passive protection of structure when an earthquake occurs, because it modifies the structural global response and improves seismic performance. In this study, a Base-Isolated (BI) structure was modeled using Finite Element Method (FEM) in which modal and nonlinear time-history analyses were undertaken using the seismic scaled records of near-fault earthquakes. Furthermore, three various Optimal Sensor Placement (OSP) algorithms were used and Genetic Algorithm (GA) was selected to act as the solution of the optimization formulation. A novel numerical approach was proposed for OSP which was called Transformed Time-history to Frequency Domain (TTFD) algorithm. The TTFD method uses nonlinear time-history analysis results as an exact seismic response despite the common OSP algorithms which utilize modal analysis results. Results show that with a proper OSP method for Structural Health Monitoring (SHM) can detect the weak points of BI structures.
Blasts can produce, in a very short time, an overload much greater than the design load of a building. The blast explosion nearby or within structures causes catastrophic damage to the building both externally and internally. This study intends to model a Cold-Formed Steel (CFS) building using Finite Element Method (FEM) in which material properties of the model are defined according to results of performed laboratory tests. Then accelerograph record of a standard blast was applied to the Finite Element (FE) model. Furthermore, various Optimal Sensor Placement (OSP) algorithms were used and Genetic Algorithm (GA) was selected to act as the solution of the optimization formulation in selection of the best sensor placement according to the blast loading response of the system. In this research a novel numerical algorithm was proposed for OSP procedure which utilizes the exact value of the structural response under blast excitation. Results show that with a proper OSP method for Structural Health Monitoring (SHM) can detect the weak points of CFS structures in different parts efficiently.