@article{nojavan_yuan_2009, title={Damage identification using electromagnetic waves based on born imaging algorithm}, volume={135}, DOI={10.1061/(ASCE)0733-9399(2009)135:7(717)}, abstractNote={Reconstructing damage geometry with computationally efficient and effective algorithms is of primary importance in establishing a robust structural health monitoring (SHM) system. In this paper, Born imaging algorithm is proposed for three-dimensional (3D) damage imaging of reinforced concrete structures using electromagnetic waves. This algorithm is derived in time domain for inhomogeneous isotropic and lossy structures. In order to reduce the computational cost of the algorithm, different imaging conditions are introduced. Numerical simulations in a 2D transverse magnetic case for a reinforced concrete slab with multiple damages are performed to test the effectiveness of the algorithm. In this simulated study, sensor data, incident field, and back-propagated field are computed via a finite difference time-domain method. It is concluded that the proposed imaging algorithm is capable of efficiently identifying the damages’ geometries and may be employed in a SHM system.}, number={7}, journal={Journal of Engineering Mechanics}, author={Nojavan, S. and Yuan, F. G.}, year={2009}, pages={717–728} }
 @article{nojavan_yuan_2006, title={Damage imaging of reinforced concrete structures using electromagnetic migration algorithm}, volume={43}, ISSN={["0020-7683"]}, DOI={10.1016/j.ijsolstr.2005.08.017}, abstractNote={Reconstructing damage geometry with computationally efficient algorithms is of primary importance in establishing a robust structural health monitoring system (SHMS). In this paper electromagnetic migration, a linearized imaging algorithm, is adopted to image the damages in reinforced concrete structures. This algorithm is formulated in time-domain for 3-D inhomogeneous isotropic and lossy structures. In order to reduce the computational cost and to examine the damage resolution of this imaging algorithm, different imaging conditions are introduced. Numerical simulations in 2-D transverse magnetic (TM) wave for a reinforced concrete slab with multiple damages are performed to test the effectiveness of the algorithm. All synthetic sensor data, incident field, and migration field are computed via a finite difference time-domain (FDTD) method. It is concluded that the proposed imaging algorithm is capable of efficiently identifying the damages geometries, is robust against measurement noise, and may be employed in a SHMS.}, number={18-19}, journal={INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES}, author={Nojavan, Saeed and Yuan, Fuh-Gwo}, year={2006}, month={Sep}, pages={5886–5908} }