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Effects of shear panel dampers on seismic response mitigation of high-speed railway simply supported bridge-track system under far-field and near-field ground motions

Jiang Liqiang, Yu Kai, Jiang Lizhong, Wen Tianxing, Hu Yi, Pang Lin

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e93, 2023

EN

High-speed railway lines always have to cross the seismic zone with great earthquake risks leading to serious consequences. A replaceable steel panel damper (SPD) is proposed as an energy-dissipation device to mitigate the structural seismic responses. It is simulated as a simplified nonlinear spring embedded in structural system with the force-displacement behavior derived by plate-beam theory. To investigate the effect of SPD, a typical 5-span high-speed railway simply supported bridge-track system (HSRSBTS) validated by a shaking table test is established by ANSYS. A novel damage measure, the system relative damage ratio (γSRD), is proposed to quantify the effect of SPD in the system and consider the potential component-level damage modes of both bending and shear. The structural system is investigated undergoing two ground motions suites in DBE- and MCE-level intensity, including both far-field and near-field records in transverse direction. The result indicates that a significant reduce (roughly 50%) of seismic response in rail and girder are contributed by SPD, while the system damage decreases about 10-15%, especially for near-field pulse-like ground motions with high intensity. The energy-dissipation capacity of SPDs with various configurations is examined to optimize the properties of SPD. It generally decreases with the increase in the elastic stiffness ratio r of the SPD to the fixed support, and the r = 2-2.5 are recommended in engineering practice. SPD is an effective and efficient device of structure to be adopted as an energy-dissipation component and the first defense line under far-field and near-field ground motions.

2

Cyclic performance and shear resistance design of asymmetric diagonal stiffened beam-only-connected corrugated steel plate shear walls

Zheng Hong, Zhang Zhibin, Jiang Liqiang, Hu Yi, Wang Wei

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e183, 2022

EN

The corrugated plate steel shear walls (CSPWs) are widely used as lateral force resistant members in high-rise buildings. However, buckling failure still easily occurred on corrugated steel plates subjected to earthquake loads, which is not good for the energy dissipation of structures. In this paper, the asymmetric diagonal stiffened beam-only-connected corrugated steel plate shear wall (ASW) is proposed. A test-validated FE modeling method is used to investigate the seismic performance of ASW, and the results are compared with the results of unstiffened corrugated steel plate shear wall (USW). Then parametric studies on the height-to-thickness ratio, wavelength, wave height of the corrugated plate and width-to-thickness ratio of the stiffeners are performed to investigate their effects on the seismic performance of ASW. Finally, a simplified theoretical model is developed to calculate the shear resistance of ASW, and the results are validated by tests and FE results. The results show that: (1) compared to the USW, the yield load and ultimate load of ASW increase 11.7% and 13.2%, respectively; (2) the theoretical calculation results are basically consistent with the FE and test results, and the errors between them are within ± 15%. These results can be used for seismic enhancement of CSPWs and seismic design of ASW.

3

On the steady-states of a two-species non-local cross-diffusion model

Rodríguez Nancy, Hu Yi

Journal of Applied Analysis

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2020

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Vol. 26, nr 1

1--19

EN

We investigate the existence and properties of steady-state solutions to a degenerate, non-local system of partial differential equations that describe two-species segregation in homogeneous and heterogeneous environments. This is accomplished via the analysis of the existence and non-existence of global minimizers to the corresponding free energy functional. We prove that in the spatially homogeneous case global minimizers exist if and only if the mass of the potential governing the intra-species attraction is sufficiently large and the support of the potential governing the interspecies repulsion is bounded. Moreover, when they exist they are such that the two species have disjoint support, leading to complete segregation. For the heterogeneous environment we show that if a sub-additivity condition is satisfied then global minimizers exists. We provide an example of an environment that leads to the sub-additivity condition being satisfied. Finally, we explore the bounded domain case with periodic conditions through the use of numerical simulations.

4

Seismic behavior of concrete-filled double-skin steel tube/moment-resisting frames with beam-only-connected precast reinforced concrete shear walls

Hu Yi, Zhao Junhai, Zhang Dongfang, Chen Yanxiong

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 4

967--980

EN

Concrete-filled double-skin steel tube (CFDST) attracts attention from researchers for it exhibits high strength, good ductility and energy dissipation capacity. In this paper, CFDST frame with beam-only-connected precast reinforced concrete shear wall system is pro-posed, and all the joints used high-strength bolt connection to realize fully-prefabricated construction. Three specimens were tested to obtain the seismic performance and coopera-tive mechanism of such proposed systems, and the contribution of beam-only-connected precast reinforced concrete shear wall (BRW) was quantified by comparing the results of these specimens. The results show that: (1) the BRW cooperated well with the CFDST frames, and it significant enhanced the lateral stiffness and strength of the CFDST frame; (2) all specimens tolerated more than 4% inter-story drift ratio, indicating that the specimens have good lateral deformation capacity; (3) the specimen with two pieces of BRW (BF-BRW-B) exhibited better ductility ratio by comparing with the specimen without BRW (BF) and with only one piece of BRW (BF-BRW-A); (4) relative brittle failure was occurred on the BRW in BF-BRW-A due to the shear force, which resulted in significant strength degradation and ductility reduction of the specimen, but two BRWs in BF-BRW-B could mitigate such situations. Lastly, equations were proposed to predict the lateral resistance of the test specimens.