An analysis of pounding mitigation and stress waves in highway bridges with shape memory alloy pseudo-rubber shock-absorbing devices

Abstract

Summary Seismic‐induced pounding between adjacent structures that are insufficiently separated can cause significant structural damage, even collapse, during severe earthquakes. This paper presents an experimental and numerical investigation into mitigating pounding on highway bridges using novel shape memory alloy pseudo‐rubber shock‐absorbing devices (SMAPR‐SADs). The mechanical properties and a theoretical model of SMAPR‐SADs are briefly introduced and investigated. Next, a series of shaking table tests on a 1:30 model of a steel highway bridge are conducted to investigate the effectiveness of the SMAPR‐SADs in mitigating the pounding of the structures. Based on the experimental results, the pounding‐induced stress waves are analyzed using wave theory and the cross‐wavelet transform method. Subsequently, numerical models of highway bridges with and without SMAPR‐SADs are proposed. The pounding mitigation mechanism of SMAPR‐SADs is analyzed using the momentum theorem, their ability to dissipate energy, and stress wave absorption theory. Two indexes representing the energy absorption and dissipation abilities of SMAPR‐SADs are proposed and investigated. Finally, the effect of the axial stiffness of SMAPR‐SADs on pounding mitigation is analyzed. The experimental and theoretical results demonstrate that SMAPR‐SADs are able to absorb energy stably and can significantly reduce the pounding response of highway bridges under seismic excitations. Copyright © 2016 John Wiley & Sons, Ltd.

Theoretical investigation on the impact effect in dynamic analysis of self‐centering pier system based on the Hertz contact‐pounding model

“…The impact force and corresponding impulsive contact stress were difficult to obtain; however, it is important to further study the dynamic properties and damage analysis in the SC system. In addition, it is noted that the classical contact-pounding element model (Figure 3) is widely employed in impact problems [18][19][20]23,24 in adjacent bridge structures (including frontal and oblique impacts) and can accurately capture the time-history results of impact and damping forces. Several theoretical contact-pounding models have been investigated and selected in the study of pounding process, such as the liner model, the Kelvin model, and the Hertz model, etc.…”

“…However, those modified values could be applied to the other analyses in the same structure. The authors have performed many shaking table tests of pounding problems 23,24 and the results indicated that the parameters of Hertz model calculated by the equations still could provide a reasonable reference value. As shown in Figure 9, the lateral displacement response of the FEM and proposed theoretical model agree well with the test results.…”

“…The Hertz contact‐pounding model 18,19 was widely applied in many impact analyses, the authors 23,24 also had investigated the pounding responses of adjacent bridge structure by employing the Hertz model, and the numerical results showed that this model could accurately capture the pounding responses in the impact events including the impact force. Figure 3 presents the constitutive model of the contact‐pounding element, where F p is the impact force; D p is the width of gap; x 1 and x 2 denote the displacement of the adjacent structure; K Hertz is the stiffness of the pounding spring; C Hertz is the damper element that accounts for energy dissipation during impact.…”

Comparative study of two types of self-recovery shape-memory alloy pseudo-rubber isolator devices under compression–shear interactions

“…It has high elasticity, large restorable deformation, and a self-recovery ability. All the SMAPR specimens in this study were fabricated at the Metallic Pseudo-Rubber Technique Research Centre of the Harbin Institute of Technology (Jiang et al, 2001;Li et al, 2011Li et al, , 2016. The SMAPR specimens comprised martensite NiTi (50 at.% Ni) SMA wires with a diameter of 0.2 mm, and the martensitic SMA wires used in this study were fabricated from austenitic NiTi wires at room temperature.…”

Design of New Self-Resetting Negative Stiffness Mechanism for Shock Absorption Based on Finite Element Method

“…In 2015, Singh and Satpute pointed out that energy dissipation and seismic reduction technology based on traditional design can greatly improve the seismic, wind and seismic capacity of buildings and structures, effectively reduce the response and damage of wind and earthquake to structures, and improve the seismic capacity and seismic performance of structures [3]. In 2016, Li et al proposed a method for seismic strengthening of four-to six-storey frame structures with friction dampers, which are located in the 8-degree earthquake intensity zone and site II [4]. In 2015, Pu et al used friction dampers to analyze and calculate the seismic strengthening of frame structures with six stories, which effectively improved the seismic performance of structures.…”