Time filter

Source Type

Li H.,Hainan University | Li H.,Zhejiang University | Yuan L.,China Haisum Engineering CO.
Applied Mechanics and Materials | Year: 2014

A kind of deterministic small-world network is constructed based on polygonal nesting with discrete degree distribution. By adding contrapuntal edges and alternate-position edges between adjacent nests, the intra-nest edges and the long-range edges from the central node to certain outer layer nodes, the proposed polygonal nesting small-world (PNSW) networks have the property of large clustering coefficients. Also these kinds of PNSW networks have small diameter, average node degree and average path length, whose moments of k order are given. © (2014) Trans Tech Publications, Switzerland.

Huang X.,Tianjin University | Bao H.,China Haisum Engineering Co. | Hao Y.,Curtin University Australia | Hao H.,Curtin University Australia
International Journal of Structural Stability and Dynamics | Year: 2016

Significant research efforts have been invested on studying the response and damage of structures subjected to blast loads for better life and property protections. The single-degree-of-freedom (SDOF) approach has been widely adopted to simplify the structural response analysis for engineering design purpose. However, such an approach under certain circumstances oversimplifies the structural behavior and might not give reliable predictions of structural responses to blast loads. On the other hand, although detailed high fidelity finite element (FE) approach is able to give relatively accurate predictions of structural response, it is unfortunately not straightforward for application and very time-consuming, which impedes its application among engineers. Therefore, a method that can assure not only reliability but also efficiency is highly needed for design practice. In the present study, mode approximation method with Pressure–Impulse (P-I) diagrams is applied to analyze response and damage of RC slab due to blast load. Slab under analysis is assumed rigid-plastic and simply supported. Shear failure, bending failure and combined failure modes are considered based on different failure modes. Critical equations for structural shear and bending failures are derived respectively with appropriate failure criteria. P–I diagrams are then developed for quick damage assessments. The analytical results are verified by comparing with high fidelity numerical simulations. The reliability and efficiency of using this approach for design and analyzing RC slab response under blast loads are demonstrated. © 2016 World Scientific Publishing Company

Xie Q.,Tongji University | Li J.,Tongji University | Yan C.,China Haisum Engineering Co. | Zhou Y.,Tongji University
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013

To clarify the wind load transferring mechanism of tower-line system, a wind tunnel test on a four-span tower-line system model was carried out in TJ-3 wind tunnel at Tongji University with the prototype in the Huainan-Shanghai 1000kV ultra high voltage (UHV) electric power transmission project. An aero-elastic model of the double circuit tower and eight-bundled conductors coupling system was designed. Besides the measurement of acceleration and displacement, Fiber Bragg grating sensors were used to measure the dynamic strain of the conductors, insulators and tower main members. It is found from the analysis that the dynamic characteristics of power transmission tower-line system under wind load are greatly influenced by the tower-conductor coupling effects. As wind speed goes up, the contribution of higher order vibration modes of the conductors to the total energy of the system increases as well. © 2013 Chinese Society for Electrical Engineering.

Zhang Y.,East China Grid Company | Yan C.,China Haisum Engineering Co. | Xie Q.,Tongji University
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2010

The current design code requests that wind actions should be considered in the design of icing transmission tower. Taking 1000 kV double circuit transmission lines of an ultra high voltage (UHV) transmission project as the prototype, a large wind tunnel test on icing aeroelastic model was carried out to find out the dynamic interaction of wind-induced vibration for icing transmission tower-line coupling system. The aerodynamic characteristics of the transmission tower-line system were simulated and the boundary conditions were simulated by the equivalent towers. The vibration response of acceleration and displacement were observed in the test. Compared with its counterpart without icing, it was found that the damping ratio in the icing system increased a lot. The dynamic strains of the eight-bundled conductors were measured by using fiber Bragg grating (FBG). The dynamic property variation of the icing conductor and its impact on the transmission tower under the wind load were investigated. The results show that the reasonable dynamic interaction under turbulence flow in the icing tower-line coupling system should be taken into account. © 2010 Chin. Soc. for Elec. Eng.

Xie Q.,Tongji University | Guan Z.,Tongji University | Yan C.,China Haisum Engineering Co.
Dianwang Jishu/Power System Technology | Year: 2011

To research across-wind-induced vibration response of ultra high voltage (UHV) transmission tower and that of tower-line coupling system, taking a certain 1000 kV transmission line as research object, through wind tunnel test of aeroelastic model the across-wind-induced vibration responses of both single tower and tower-line coupling system under turbulent flow are researched. Test results show that in turbulent wind field the across-wind-induced vibration response and the along-wind-induced vibration response of single transmission tower are in the same order of magnitude. In tower-line coupling system, the across-wind acceleration response of the tower is larger than that of the single tower; the across-wind displacement response at the end of the crossbeam is larger than that of the single tower and the across-wind displacement response at the tower body is smaller that that of the single tower. The influence of high order vibration modes on the acceleration and displacement responses cannot be neglected, and there is a certain extent of background response involved in displacement response. Thus in the wind force proofing design of UHV transmission tower the influence of across-wind response should be taken into account.

Xie Q.,Tongji University | Yan C.-Y.,China Haisum Engineering Co. | Zhang Y.,East China Grid Company
Gaodianya Jishu/High Voltage Engineering | Year: 2010

Vibration of ice covered conductors under low speed wind is a complex problem. It is important to calculate the wind-induced dynamic tension of ice covered conductors for the ice resistant design of transmission towers. By using fiber Bragg grating (FBG) sensors, the dynamic strains of the conductors were measured in the wind tunnel test on a simulated ice covered UHV transmission tower-eight bundled conductors coupling system. Validity of the conductor dynamic tension model was verified in the test. The calculation results of the dynamic tension model were compared with those obtained according to the current design code. The results of the dynamic strain of the ice covered conductor measured in the wind tunnel test and calculated analytically show that , with the increase of the ice thickness, the natural frequencies of the conductors become lower and the nonlinearity of the conductor becomes severe. Especially, the dynamic tension of the conductor end remarkably increases. The chord wise tension load of ice covered conductor calculated by the design code is slightly less than that of the theoretical model. The unequal tension on transmission towers caused by the ice covered conductors will become one of the major causes for possible structural failures.

Xie Q.,Tongji University | Yan C.-Y.,China Haisum Engineering Co. | Li S.-Z.,Tongji University
Gaodianya Jishu/High Voltage Engineering | Year: 2010

It is very important to consider the variation of the wind induced dynamic tension in lines when designing the transmission tower-line coupling system subjected to wind. Taking a 1000 kV UHV transmission project under construction as the prototype, we designed a 1000kV double circuit tower-eight bundled conductors coupling system and tested its scaled aeroelastic model in wind tunnel. In the experiment, fiber Bragg grating sensors, for the first time, were used to measure the wind induced dynamic strain of the bundled conductors. The dynamic tension transmission rule and the characteristics of dynamic responses of the conductors were derived from the measured dynamic strains under several different test cases, which differ in wind attack angles, flow fields and wind speeds, etc. Analysis of the strain distribution and the power spectra density at different locations in the conductor verified the energy exchange law between the conductor and the tower in the transmission tower-line coupling system. The results show that the dynamic tension should be considered in wind resistant design of transmission tower-line coupling system.

Luo G.-H.,China Haisum Engineering Co. | Chen Q.,China Haisum Engineering Co. | Tao H.,China Haisum Engineering Co.
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2015

Current domestic project management model in pulp & paper industry was introduced, the reasons of quality management in EPC projects of pulp & paper industry is necessary attention and enhancing quality management measurement were analyzed, the paper suggested that QA & QC must be the key points in quality management process, meanwhile the quality feedback and continuous improvement as well as project documents collection and filing in project quality management should be paid more attention. ©, 2015, China Technical Association of Paper Industry. All right reserved.

Qu S.-G.,China Haisum Engineering Co. | Yang J.-B.,Voith Paper China Co.
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2014

Based on the design procedure of the latest modern tissue machine white water system the article systematically elaborates the basic procedure and principle of the design of the tissue machine white water system. Furthermore, the key points in the disc filter system design were illustrated in detail, which may provide reference to related designers or process engineers in paper mills.

Tian Q.,Nanyang Technological University | Zhao Z.,Nanyang Technological University | Bao H.,China Haisum Engineering Co.
International Journal for Numerical and Analytical Methods in Geomechanics | Year: 2014

As a hybrid method, the nodal-based discontinuous deformation analysis (NDDA) greatly improves the stress accuracy within each DDA block by coupling a well-defined finite element mesh inside the DDA block; at the same time, the NDDA inherits the unique block kinematics of the standard DDA method. Each finite element mesh line inside the DDA block is treated as a potential crack, which enables the transformation of the block material from continuum to discontinuum through the tensile and shear fracturing mechanism. This paper introduces a double minimization procedure into the NDDA method to further improve the accuracy of the stresses evaluated at the finite element mesh lines and thus to obtain a more realistic fracture model. Three numerical examples are employed to demonstrate the improved stress accuracy by the implemented double minimization procedure and the accuracy and capability of the enhanced NDDA method in capturing brittle fracturing process. © 2013 John Wiley & Sons, Ltd.

Loading China Haisum Engineering Co. collaborators
Loading China Haisum Engineering Co. collaborators