Time filter

Source Type

Zhai X.-M.,Harbin Institute of Technology | Huang M.,China IPPR International Engineering Corporation
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2014

Dynamic finite element software ANSYS/LS-DYNA was used to set up a typical finite element model for a Kiewitt8 single-layer reticulated shell containing reticulated shell member, purlin hanger, purlin, rivet, roof boarding, wall and ground. The dynamic response of the structure subjected to internal eccentric blast loading was studied by using ALE (Arbitrary-Lagrange-Euler) algorithm. Four response types were defined, they were: no impairment, member plastically developing, large deformation of reticulated shell and destruction with explosion relief. The response rules of the structure under internal eccentric blast loading with variation of explosion point position, section size of reticulated shell member, rise-span ratio, supporting condition and thickness of roof boarding were obtained through comparisons of plastic strains, plastic development levels and displacements of the structure. The results provided a theoretical basis for reasonable defense and anti-blasting design of reticulated shell structures.

Ma T.,Zhejiang University | Zhao X.-Z.,Zhejiang University | Zhao X.-Z.,China IPPR International Engineering Corporation | Gao B.-Q.,Zhejiang University | Wu H.,Zhejiang University of Finance and Economics
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2015

Shape and topology of free-form grid structures were simultaneously considered in order to reach the global optimum shapes and topologies. Optimum structural robustness was set to be the objective while parameters to define the structural shape and topology were taken as design variables. A differential evolution algorithm was used to solve the combined optimization problem. Global optimum shapes and topologies of free-form structures were obtained. The obtained results were compared with those achieved by optimizing solely shape or topology. Results showed that more robust structures with better mechanical properties were obtained, which implied the superiority of the method. The optimized structures were more efficient in carrying the load, and the resulted shape and topology clearly revealed the main force transferring paths. ©, 2015, Zhejiang University. All right reserved.

Li N.,Tsinghua University | Li N.,China IPPR International Engineering Corporation | Qian J.,Tsinghua University | Ye L.,Tsinghua University | Liu S.,Inner Mongolia Mengxi Engineering Design Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2016

Quasi-static tests of four precast concrete shear wall specimens with shear span ratio of 2.11 were conducted. The vertical rebar of the precast shear wall was spliced by pressed sleeves. Among them, three shear walls had a rectangular section and the axial load ratios were 0.5, 0.6 and 0.2 respectively. One shear wall had a T section and an axial load ratio 0.5. The test results indicate that the shear wall specimens fail in compression and flexure interaction. The vertical rebars at boundary elements yield in tension and concrete at the edge of wall bottom crush in compression. The lateral force-displacement hysteretic loops have a degree of pinch. The ultimate rotation angles of the shear walls with rectangular section and T section, where the flange is in compression, are not less than 1/80. The ultimate rotation angle of shear wall with T section, where the web is in compression, is 1/110. The ratio of the measured compression-flexure strength to the calculated strength according to the formula of GB 50010-2010 is about 1.20 for the shear walls with rectangular section. The ratios become 1.04 and 1.11 for walls with T section, where the flange and web are in compression respectively. The pressed sleeve connector can transfer the tensile and compressive forces of rebar effectively. The seismic behavior of the precast shear wall with the vertical rebar splicing by pressed sleeve satisfies the current code requirements. © 2016, Science Press. All right reserved.

Zhai X.,Harbin Institute of Technology | Huang M.,China IPPR International Engineering Corporation
Journal of Earthquake Engineering and Engineering Vibration | Year: 2012

Finite element software ANSYS/LS-DYNA is used to establish a refined kiewitt8 single-layer reticulated shell finite element model,which contains reticulated shell member, purlin hanger, purlin, rivet and roof boarding to simulate the dynamic responses of a structure subjected to external blast loading by using ALE (Arbitrary-Lagrange-Euler) algorithm. The strain rate effect of materials and the inter-collision of the components are considered. The responses of the structure under external eccentric blast loading with varied TNT equivalent weights, explosion point position, section size of reticulated shell bar, rise-span ratio, supporting condition, thickness of roof boarding, roof boarding load and the form of roof boarding are obtained by the comparison of the plastic strain, the plastic development degree and the displacement of the structure, which could provide a reference for reasonable defense design of reticulated shell structure to resisting blast. The results show that with the changes of each parameter, there are four damage modes of kiewitt8 single-layer reticulated shell under external blast loading, that is intact, local deformation local damage and total collapse.

Ke X.-J.,Xian University of Architecture and Technology | Ke X.-J.,Guangxi University | Chen Z.-P.,Guangxi University | Xue J.-Y.,Xian University of Architecture and Technology | Ma F.-B.,China IPPR International Engineering Corporation
Gongcheng Lixue/Engineering Mechanics | Year: 2013

In order to reveal the bond-slip behaviour between steel and concrete in SRC special-shaped columns under dynamic actions, 17 specimens were designed for experimental research. By the strain gauges and slip sensors embedded on the steel flange surface, the bond stress distribution along column, loading-slip hysteretic curves and skeleton curves were obtained. The influence of loading reversed times on bond stress was analyzed, calculation formula for bond degeneration was presented, and bond-slip constitutive relation in various places was established. Research results show that bond stress and slip are respectively distributed in parabola and exponential curve along columns. The maximum bond stress occurs in the upper, middle and lower of column, so these positions are vulnerable to bond failure. With the increasing of loading reversed time, bond stress decreased while slip increases gradually, indicating the occurring of bond degeneration. At the beginning of loading, loading-slip hysteretic curve is chubbiness, but it gradually becomes Z-shaped and pinched by the increasing of loading. The whole bond-slip failure can be divided into non-slip stage, elastic stage, elastic-plastic stage and plastic stage.

Discover hidden collaborations