Time filter

Source Type

Cao J.-L.,Tongji University | Shi W.-X.,Tongji University | Liu W.-G.,Shanghai University | Jiang X.-M.,CNGC Wuzhou Engineering Design and Research Institute
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2011

Relative displacement response spectrum is not only essential in seismic design of a long-period structure but also in displacement-based seismic design and in structural control design. However, the spectrum specified by seismic codes is a normalized absolute acceleration spectrum. Problems existing in long-period range of relative displacement spectrum in codes were pointed out here. By selecting 80 high-pass filtered digital horizontal strong motion records (PGA (peak ground acceleration) ≥ 0.10 g) with lower cut off frequency (0.025 Hz ~0.125 Hz), relative displacement spectrum was constructed with period range (0~10.0 s) and damping ratio range (0.10~0.40). Furthermore, spectral influence factors and control parameters were calculated and illustrated. Taking influence of hypocenter parameters, ground motion amplitude, site conditions, spectral control parameters and damping ratio adjustment factors on relative displacement spectrum into account, elastic relative displacement spectrum and relevant practical calculation formula for a long-period structure were proposed. Moreover, value of PGD (peak ground displacement) was given based on statistical analysis. The results revealed that predominant period is one of significant parameters controlling the value and shape of the relative displacement spectrum, and the relative displacement spectrum established here is capable of fitting real displacement spectrum.


Ding D.,Hefei University of Technology | Ding D.,CNGC Wuzhou Engineering Design and Research Institute | Wang Y.,Tsinghua University | Liu L.,Tsinghua University | And 3 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011

In order to investigate the bearing behavior of the truss-to-box girder connections of the Hefei Xinqiao International Airport Terminal, two model experiments were carried out under static loading. The load-displacement curve and out-of-plane displacement were measured, as well as the strain at the concerned positions. The failure modes of the truss-to-box girder connections were obtained. Finite element analysis models were established. The bearing behavior of the connections was simulated and the results of experiments and FEA models were compared. The results show that the specimens are elastic state under the design load, and prove the design is reasonable and safe. The scaled model ZHJD-1 is in a brittle failure state with weld fracture, and the full scale model ZHJD-2 is with a compression buckling damage in the tube. The experiment results and FEA results agree well. The effects of different initial defects applied on the models are analyzed. The truss-to-box girder connection models are not sensitive to the initial defects.


Xu G.,Tsinghua University | Zheng C.,Tsinghua University | Zhang Q.,Tsinghua University | Huang J.,Tsinghua University | And 4 more authors.
Nano Research | Year: 2011

Novel inexpensive, light, flexible, and even rollup or wearable devices are required for multi-functional portable electronics and developing new versatile and flexible electrode materials as alternatives to the materials used in contemporary batteries and supercapacitors is a key challenge. Here, binder-free activated carbon (AC)/carbon nanotube (CNT) paper electrodes for use in advanced supercapacitors have been fabricated based on low-cost, industrial-grade aligned CNTs. By a two-step shearing strategy, aligned CNTs were dispersed into individual long CNTs, and then 90 wt%-99 wt% of AC powder was incorporated into the CNT pulp and the AC/CNT paper electrode was fabricated by deposition on a filter. The specific capacity, rate performance, and power density of the AC/CNT paper electrode were better than the corresponding values for an AC/acetylene black electrode. The capacity reached a maximum value of 267.6 F/g with a CNT loading of 5 wt%, and the energy density and power density were 22.5 W·h/kg and 7.3 kW/kg at a high current density of 20 A/g. The AC/CNT paper electrode also showed a good cycle performance, with 97.5% of the original capacity retained after 5000 cycles at a scan rate of 200 mV/s. This method affords not only a promising paper-like nanocomposite for use in low-cost and flexible supercapacitors, but also a general way of fabricating multi-functional paper-like CNT-based nanocomposites for use in devices such as flexible lithium ion batteries and solar cells. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


Wang Y.-Q.,Tsinghua University | Liu L.-Y.,Tsinghua University | Liu L.-Y.,Beijing Institute of Architecture Design | Ding D.-Y.,CNGC Wuzhou Engineering Design and Research Institute | And 2 more authors.
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2013

To get the bearing behaviors of the curved girders, three model experiments were carried out under tensile force by way of a single jack. The load-displacement curve, out-plane displacement were measured, as well as the strain at the concerning positions. Target curves and expected failure mode of the experiment components were obtained. Finite element models were established. The bearing behaviors of the curved girders were simulated and the results of experiments and FEM were compared. By different types of out-plane supporters, different effects were obtained. The effects of different initial defects applied on the models were analyzed as well. The results show that the experiment results and FEM results agree well, and the design is reasonable and safe.


Wang Y.,Tsinghua University | Liu L.,Tsinghua University | Liu L.,Beijing Institute of Architecture Design | Ding D.,CNGC Wuzhou Engineering Design and Research Institute | And 2 more authors.
Applied Mechanics and Materials | Year: 2011

Hefei Xinqiao International Airport Terminal is a steel structure consisting of long-span rigid frames, with 804m in length and about 161m in width at the widest part. The long-span frame consists of box columns, large curvature beams, tapered box beams and space trusses. The joints between space trusses and box beams named truss-to-box beam connections are the critical parts of the whole structure, because of the discontinuity in geometries and stiffness which result in high stress concentrations and complicated mechanical properties. GJ3-6, GJ3-5 and GJ3-1 of the airport terminal are modeled by ABAQUS. Structure internal forces at six load combinations of bearing capacity limit state are calculated. Lower chords of the landside connections sustain large tensions, while web members of the airside connections sustain large pressures. Since these truss bars are directly connected to cover plate of the box beam, better design details are recommended to reduce the stress concentrations caused by geometrical discontinuity. © (2011) Trans Tech Publications, Switzerland.

Loading CNGC Wuzhou Engineering Design and Research Institute collaborators
Loading CNGC Wuzhou Engineering Design and Research Institute collaborators