![]() ![]() ![]() Results demonstrated that using ferrous SMA wires (FeNCATB) with 13.5% superelastic strain in the cross configuration leads to the best performance since the strain induced in wires is significantly decreased. A performance-based design flowchart is also provided along with a design example for determining the pre-strain and the radius of cross section of wires in the SMA wire-based rubber bearings. Two different configurations of SMA wires incorporated in rubber bearings are compared by changing the aspect ratio of base isolator, the type of SMA, the thickness of wires, and the pre-strain in wires where the isolator is subjected to a vertical pressure and unidirectional cyclic lateral displacement. Due to the superelastic effect and the re-centering capability of SMAs, the residual deformation in SMA-based elastomeric isolators is reduced. This study deals with two new generation smart high damping rubber bearings (HDRBs) incorporated with shape memory alloy (SMA) wires. An important point is that the shear hysteresis of the DC-SMAW model looks different from the flag-shaped hysteresis of the SMA because of the specific arrangement of wires and its effect on the resultant forces transferred from the wires to the rubber bearing. ![]() The developed constitutive model for DC-SMAWs is characterized by three stiffnesses when the shear strain exceeds a starting limit at which the SMA wires are activated due to phase transformation. Comparing the hysteretic response of decoupled systems with that of the SMA-LRB shows that the high recentering capability of the DC-SMAW model with zero residual deformation could noticeably reduce the residual deformation of the LRB. Due to the complexity of the shear behavior of the SMA-LRB, a hysteresis model is developed for the DC-SMAWs and then combined with the bilinear kinematic hardening model, which is assumed for the LRB. An LRB is equipped with a double cross configuration of SMA wires (DC-SMAW) and subjected to compression and unidirectional shear loadings. A constitutive model for SMA-LRBs is proposed in this study. It is of great interest to implement SMA wire-based lead rubber bearings (SMA-LRBs) in bridges however, currently there is no appropriate hysteresis model for accurately simulating the behavior of such isolators. Smart lead rubber bearings (LRBs), in which a shape memory alloy (SMA) is used in the form of wires, are a new generation of elastomeric isolators with improved performance in terms of recentering capability and energy dissipation capacity. ![]()
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