Superelastic SMA Belleville washers for seismic resisting applications: experimental study and modelling strategy

Abstract

This study sheds considerable light on the potential of superelastic Shape Memory Alloy (SMA) Belleville washers for innovative seismic resisting applications. A series of experimental studies were conducted on washers with different stack combinations under varying temperatures and loading scenarios. The washers showed satisfactory self-centring and energy dissipation capacities at room temperature, although slight degradations of the hysteretic responses accompanied by residual deformations were induced. The hysteretic loops became stable after a few number of cycles, indicating good repeatability. The washers also showed good flexibility in terms of load resistance and deformation, which could be easily varied via changes in the stack combination. Compromised selfcentring responses were observed at temperatures below 0 °C or above 40 °C, and a numerical study, validated by the experimental results, was adopted to further investigate the deformation mechanism of the washers. A further phenomenological model, taking account of the degradation effects under varied temperatures, was developed to enable effective and accurate simulation of devices incorporating the washers. Good agreements were observed between the test and simulation results, and the model was shown to have good numerical robustness for wide engineering applications.

Feasibility of using reduced length superelastic shape memory alloy strands in post-tensioned steel beam–column connections

“…According to Sampath (2005) and Fang et al (2016), the energy dissipation capacity of SMA is largely dependent on the annealing temperature since it can change the transformation stress of SMA. Due to the change in annealing temperature, the transformation stress will change, which will eventually affect the superelastic behavior of SMA at elevated temperature (Ozbulut and Hurlebaus, 2010; Yoon and Yeo, 2008).…”

Self‐centering friction spring dampers for seismic resilience

“…The total economic losses from postearthquake demolition of a building may be substantially increased by the associated business downtime and societal impact. 24,25 However, practical concerns related to temperature sensitivity and cost may need to be addressed before SMAs are widely used in construction. The self-centering capability is provided by specially designed components such as beam-to-column connections and braces which are able to recover their inelastic deformations.…”

“…[14][15][16][17][18][19][20][21][22][23] The superelastic effect of a SMA enables up to 10% strain to be recovered upon unloading, and this high level of recoverable strain enables more compact self-centering components. 24,25 However, practical concerns related to temperature sensitivity and cost may need to be addressed before SMAs are widely used in construction.…”

Manufacturing and performance of a novel self‐centring damper with shape memory alloy ring springs for seismic resilience

“…Alternatively, SMA tendons/bars are able to offer larger load resistance, but their threaded parts are very susceptible to fracture . Other element types such as SMA helical springs, Belleville washers, and U‐shaped dampers have been shown to provide stable flag‐shaped hysteretic responses, but again, their load resistance may be small for civil engineering applications largely because that the material within these elements cannot be fully mobilised upon loading.…”