We present simulation and experimental results demonstrating the effectiveness of phase conjugation or, equivalently, time reversal metamaterials for imaging applications. Split-ring resonators are loaded with varactor diodes to enable straightforward, easy-to-fabricate phase conjugation metamaterial unit cells. These cells are improved upon to allow either completely wireless operation or more...

The effect of gradient microstructure generated by ultrasonic surface mechanical attrition treatment (SMAT) on the fatigue performance an austenitic stainless steel has been evaluated in context localized and general plasticity comparing two load ratios: fully reversed tension-compression (TC) RTC = -1 tension-tension (TT) RTT +0.1, respectively. After identical SMAT processing conditions, limi...

When earthquakes occur, energy released by the earthquake gets induced into the structure as ground motion and this energy has to be dissipated for safety reasons. To release seismic energy, the structure should damage in such a way that on one hand, collapse of structure should not occur and on the other hand, after the earthquake, damage should be economically feasible to repair. To avoid the...

Describing the moment rotation (M/θ) behavior of reinforced concrete (RC) hinges is essential in predicting the behavior of RC structures under severe loadings, such as under cyclic earthquake motions and blast loading. The behavior of RC hinges is defined by localized slip or partial interaction (PI) behaviors in both the tension and compression region. In the tension region, slip between the ...

Sixteen large-scale reinforced concrete specimens without web reinforcements were tested to study the behavior of typical bridge piers subjected to deflection reversals that were large enough to cause extensive yielding of the longitudinal reinforcement. The different parameters considered included shear spanto-depth ratio, percentage of longitudinal reinforcement, frequency of the applied load...