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Cai C.,China Institute of Metrology | Xu J.,Beijing Institute of Architecture Design | Li J.,China Institute of Metrology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

The intrinsic microseism in a precision metrology laboratory of National Institute of Metrology is used to evaluate the resolution of vibration transducers. The precision metrology laboratory is located in the Changping experimental base of National Institute of Metrology. The intrinsic microseism has been measured since 2003. The frequency of the intrinsic microseism is about 3.2 Hz, and the velocity magnitude of the intrinsic microseism is about 5×10-8 m/s. The long term measure proved the frequency and magnitude of the intrinsic microseism is stable, and it can be used as a natural standard to evaluate the resolution of vibration transducers. The vibration transducers and a reference vibration transducer are located in a seismic block. The reference vibration transducer has enough vibration resolution to measure the intrinsic microseism. The vibration transducers and the reference vibration transducer measure and record the ambient vibration at the same time in a measurement period, e.g. 15 minutes, 2 hours or 24 hours. The recorded data are analyzed by FFT with average analysis in full-time process to gain the average spectrum. If the 3.2 Hz intrinsic microseism could be measured by the vibration transducers, the resolution of the vibration transducers will precede the magnitude of the 3.2 Hz intrinsic microseism which is measured by the reference vibration transducer. The signal noise ratio in the average spectrum can further affect the measure results. © 2013 SPIE.


Su Y.,Tsinghua University | Pan P.,Tsinghua University | Deng K.,Tsinghua University | Miao Q.,Beijing Institute of Architecture Design | Li W.,Beijing Institute of Architecture Design
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2014

Pseudo-dynamic substructure tests were applied to a retrofit project of old residential buildings in Beijing. An integration algorithm, i.e. operator-splitting (OS) method, was outlined, and its implementation in pseudo-dynamic test was presented. A test program called Tsinghua online hybrid test program (TOHTP) was developed based on MTS servo hydraulic test system. The test program was applied to pseudo-dynamic tests of a 1/2 scaled model of a residential building retrofitted by exterior strengthening method. Major conclusions obtained in this study are as follows: OS method, which is unconditional stable for most cases, is suitable for pseudo-dynamic test; TOHTP, which implements OS method correctly, is effective to pseudo-dynamic test of building structures; the performance of the retrofitted residential building can satisfy the requirements prescribed in current seismic design code.


Liu J.,Tsinghua University | Lin B.,Tsinghua University | Zhang Y.,Beijing Institute of Architecture Design | Zhu Q.,Beijing Institute of Architecture Design | Zhu Y.,Tsinghua University
Proceedings of Building Simulation 2011: 12th Conference of International Building Performance Simulation Association | Year: 2011

As a famous large-scale transportation hub in China, the Nanjing South Railway Station (NSRS) is a huge building of 380,000 m2 and 50 meters high, with complex vertical route organization and comprehensive function zones. Because of its large façade, skylight, and huge air infiltration, the NSRS has encountered many difficulties in terms of HVAC (heating, ventilation, and air-conditioning) design, especially in calculating the most accurate heating and cooling loads during air infiltration. In order to address these issues, DeST (Designer's Simulation Toolkit), a building energy simulation tool developed by Tsinghua University, was combined with other tools to simulate the NSRS's HVAC load for an entire year. It is hoped that the results of this study will be helpful for exploring more efficient design strategies using simulation in other similar large-scale transportation hubs.


Ding Y.,Harbin Institute of Technology | Zhao B.Y.,Harbin Institute of Technology | Wu B.,Harbin Institute of Technology | Xu G.S.,Harbin Institute of Technology | And 3 more authors.
Mechanical Systems and Signal Processing | Year: 2015

The structural damage incurred in a seismic event is always time-variant. In this paper, a new time-variant structural system identification method is proposed based on a two-stage strategy and incomplete structural acceleration responses. In the first stage, an external excitation identification method is developed for a time-variant structural system. The unknown structural response could be re-constructed with the average acceleration discrete algorithm in this stage. In the second stage, structural parameter is identified and updated with a reduced extended Kalman filter which can improve the computational effort. The re-constructed structural response and identified external excitation are used in the second stage for the damage identification and model updating. The proposed method is validated numerically with the simulation of a fifteen-storey shear frame structure subject to earthquake excitation. A model of a fourteen-storey concrete shear wall building was also studied experimentally with shaking table tests to further validate the proposed method. This shear wall building has a two-storey steel frame on top with base isolation. Both the stiffness of the model and the interface force in the isolator at the bottom of the steel frame during the seismic excitation were estimated with the proposed method. Results from both numerical simulations and laboratory tests indicate that the proposed method can be used to identify structural parameters and external excitations effectively based on a few number of polluted structural acceleration measurements. © 2015 Elsevier Ltd.


Ding Y.,Harbin Institute of Technology | Law S.S.,Hong Kong Polytechnic University | Wu B.,Harbin Institute of Technology | Xu G.S.,Harbin Institute of Technology | And 3 more authors.
Engineering Structures | Year: 2013

A discrete force identification method based on average acceleration discrete algorithm is proposed in this paper. The method is formulated in state space and the external excitation acting on a structure is estimated with regularization method. A three-dimensional three-storey frame structure subject to an impact force and random excitations is studied respectively with numerical simulations. Uncertainties such as measurement noise, model error and unexpected environmental disturbances are included in the investigation of the accuracy and robustness of the proposed method. Experimental results from a seven-storey planar frame structure in laboratory are also used for the validation. The above results are also compared with those from two existing force identification methods, which are based on the Zeroth-Order-Hold (ZOH) discrete algorithm and the First-Order-Hold (FOH) discrete algorithm. Model of a fourteen-storey concrete shear wall building is studied experimentally with shaking table tests to further validate the proposed method. The shear wall structure has a two-storey steel frame on top with base isolation. The interface force in the isolation at the bottom of the steel frame during the seismic excitation is estimated with the proposed force identification method.Results from both numerical simulations and laboratory tests indicate that the proposed method can be used to identify external excitations and interface forces effectively based on the structural acceleration responses from only a few accelerometers with accurate results. The proposed method is capable to identify the dynamic load fairly accurately with measurement noise, model error and environmental disturbances. © 2013 Elsevier Ltd.


Cai L.,Beijing University of Civil Engineering and Architecture | Li W.,Beijing Institute of Architecture Design | Zhang G.,Beijing University of Civil Engineering and Architecture | Miao Q.,Beijing Institute of Architecture Design | Wu H.,Beijing University of Civil Engineering and Architecture
Advanced Materials Research | Year: 2012

Quasi-static tests of three specimens of steel-concrete composite fabricated shear wall were performed to investigate its seismic behavior. The test results indicate that horizontal cracks run through the interface between the wall and the base beam, diagonal cracks appear on the whole prefabricated concrete shear wall. The specimens fail in the mode of bending-shear, the hysteretic curves according to the test were full, it means that they have better seismic bearing capacity.


Hu Y.,Beijing Institute of Architecture Design
IET Conference Publications | Year: 2011

This essay studies Greg Lynn's digital design method and its impact on eco-sustainable strategy, so as to show the progress of eco-bionics in building, which has evolved from directly simulating the biological forms to the application of its principles, and with the development of digital technology, eco-building has begun gradually from dream into reality, which ultimately changed the process of architect and design. By researching on the theoretical results, design examples and computer program algorithm, this essay will elaborate Greg Lynn's digital eco-design strategy (based on laws of generation) and his digital design methods which concern more about the environmental performance, as well as their main features with examples.


Chen J.Z.,Chinese Research Institute of Highway | Zhang K.C.,Chinese Research Institute of Highway | Xu Y.,Beijing Institute of Architecture Design | Zheng Y.,Chinese Research Institute of Highway
Applied Mechanics and Materials | Year: 2013

Since lamination parameters were found to represent the stiffness properties and the orientation of each ply, two major stages are defined to do the optimization. In the first stage which is called continuous optimization, the required lamination parameters will be obtained by VICONOPT but this has not been completed. This paper focuses on the second stage which is called discrete optimization. It consists of three programs and the major program is called OPBDP. Random values of required lamination parameters for 4, 8 and 16 plies lay-ups are chosen and assumed, then the results are computed and compared. What is more, a method called double up the plies is introduced and the results show that it could save a lot of solution time but is still only suitable for a small number of plies. © (2013) Trans Tech Publications, Switzerland.


Mu Z.,University of Science and Technology Beijing | Yao J.,University of Science and Technology Beijing | Zhang X.,Beijing Institute of Architecture Design
Applied Mechanics and Materials | Year: 2011

The long-span steel structure is usually used for the stadium, exhibition hall, airports, railway stations and other buildings, and these structures often have an intensive staff, stored supplies are relevant to people's livelihood and so on. If these buildings collapse under the fire, it may cause heavy casualties and property losses, so it's necessary to make a further research on its fire resistance performance. In this paper, make a fire scenario simulation to the Qingdao North Station main station by using fire simulation software FDS, in order to be sure the increased temperature of components. Then calculate stress of components under the most unfavorable fire temperature with finite element software "Midas" to make sure those components which need a fire protection. Finally, according to the analysis results to determine fire protection scheme, reduce unnecessary waste or local protection can not reach the requirements. This method of fire protection in the paper can provide reference for similar projects. © (2011) Trans Tech Publications, Switzerland.


Zhang J.,University of Science and Technology Beijing | Mu Z.,University of Science and Technology Beijing | Gan M.,Beijing Institute of Architecture Design
Advanced Materials Research | Year: 2011

wave-passage effect of the seismic is the main reason of multi-support excitations, and there are always two analysis methods which are large mass method and acceleration method to study on the multi-support excitations, this paper take one kind of trussed structure as an example, use the two methods to consider the wave-passage effect of seismic, compare the difference between the results from using the two methods, and also compare the difference between single-support and multi-support excitations. This paper draw a conclusion that it is a precise way to using ABAQUS to analysis the wave-passage effect of the seismic; wave-passage effect of the seismic has an great influence on the reaction of long-span spatial structures, it must be considered in the similar projects; and the large method and acceleration method both have their advantages and disadvantages, so we should give concrete analysis to concrete problems. © (2011) Trans Tech Publications.

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