scholarly journals Seismic Assessment of a Benchmark Highway Bridge Equipped with Optimized Shape Memory Alloy Wire-Based Isolators

2019 ◽  
Vol 10 (1) ◽  
pp. 141 ◽  
Author(s):  
Reyhaneh Hosseini ◽  
Maria Rashidi ◽  
Farshad Hedayati Dezfuli ◽  
Kamyar Karbasi Arani ◽  
Bijan Samali
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nonlinear Dynamic Analysis ◽  
Base Shear ◽  
Nsga Ii ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Negative Stiffness Device ◽  
Residual Deformations ◽  
Benchmark Highway Bridge

In this paper, an evolutionary multi-objective optimization algorithm named NSGA-II was used to determine the optimum radius for shape memory alloy (SMA) wires employed in conjunction with the lead rubber bearing (LRB), referred to as an SMA-LRB isolator. This algorithm simultaneously minimizes the mid-span displacement and the base shear force. Then, the optimized SMA-LRBs were implemented in a benchmark bridge to reduce excessive displacements. The results obtained from the nonlinear dynamic analysis show that the implemented approach could effectively optimize the SMA-LRBs. These improved smart isolators can noticeably reduce the maximum displacements and residual deformations of the structure; meanwhile, the base shear and deck acceleration remain less than those of the non-isolated benchmark bridge. This isolator can reduce the maximum mid-span displacement of the bridge by up to 61%, and the mid-span residual deformations by up to 100%, compared to an uncontrolled isolated bridge under different ground motions. This optimized passive system was compared with nonlinear dampers, passive SMA dampers, and a negative stiffness device. The results indicate that the optimized SMA-LRB isolators are generally more successful in reducing and recovering displacements than the other controllers.

Longitudinal seismic response control of long-span cable-stayed bridges using shape memory alloy wire-based lead rubber bearings under near-fault records

2017 ◽  
Vol 29 (5) ◽  
pp. 703-728 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jing-quan Wang ◽  
M Shahria Alam
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Alloy Wire ◽  
Base Shear ◽  
Alloy Wire ◽  
Near Fault ◽  
Long Span ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Rubber Bearings

This article investigates the efficiency of a new generation smart isolation system, namely shape memory alloy wire-based lead rubber bearing, for the seismic response control of long-span cable-stayed bridge systems under near-fault ground motions. The constitutive model of shape memory alloy wire-based lead rubber bearings is coded and implemented into OpenSees as a new user element. This user element can accurately predict the re-centering capability and energy dissipation capacity of shape memory alloy wire-based lead rubber bearing under different excitations. The Sutong cable-stayed bridge in China, with a main span of 1088 m, is taken as an example. Results reveal that implementing shape memory alloy wires into lead rubber bearings can effectively increase the self-centering property and, as a result, reduce the residual deformation in shape memory alloy wire-based lead rubber bearings under near-fault ground motions. Shape memory alloy wires lead to an increase in the horizontal stiffness and energy dissipation capacity of shape memory alloy wire-based lead rubber bearings. The deck displacement is restricted effectively, and a superior structural performance is achieved in terms of the deck acceleration. Shape memory alloy wire-based lead rubber bearings can effectively reduce the base shear and base moment of the towers. However, it is observed that an increase in the shape memory alloy wire diameter may have negligible effect on the deck acceleration, tower base shear and moment, and in some cases, on the pier base shear and moment.

Response of Bridges Isolated by Shape Memory–Alloy Rubber Bearing

2016 ◽  
Vol 21 (3) ◽  
pp. 04015071 ◽  
Author(s):  
Sudib K. Mishra ◽  
Sourav Gur ◽  
Koushik Roy ◽  
Subrata Chakraborty
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Rubber Bearing

Derailment of trains moving on lead rubber bearing bridges under seismic loads

2020 ◽  
Vol 26 (19-20) ◽  
pp. 1646-1655
Author(s):  
Shen-Haw Ju
Keyword(s):  
Finite Element ◽  
Seismic Loads ◽  
Base Shear ◽  
Natural Period ◽  
Train Derailment ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Lead Rubber Bearings ◽  
Dominant Period ◽  
Rubber Bearings

This study investigates the derailment of trains moving on bridges with lead rubber bearings. A moving wheel/rail axis element that couples two wheels and rails together is first developed to generate a train finite element model with 12 cars, while the sliding, sticking, and separation modes of the wheels and rails are accurately simulated. The finite element results indicate that the base shear of the bridge with lead rubber bearings is much smaller than that without lead rubber bearings. Similar to the base shear, the train derailment coefficients for the bridge with lead rubber bearings are much smaller than those without lead rubber bearings because yield lead rubber bearings during large seismic loads can change the bridge natural frequency to avoid resonance. For earthquakes with a very long dominant period, the lead rubber bearing effect to reduce the train derailment may not be obvious because the natural period of the bridge due to the full yield of lead rubber bearings can approach the dominant period of the earthquake.

Control of underground blast induced building vibration by shape-memory-alloy rubber bearing (SMARB)

2017 ◽  
Vol 24 (10) ◽  
pp. e1983 ◽  
Author(s):  
Papiya D. Mondal ◽  
Aparna D. Ghosh ◽  
Subrata Chakraborty
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Rubber Bearing ◽  
Underground Blast
Sign in / Sign up

Export Citation Format

Share Document