Papers by Author: Qing Dun Zeng

Paper TitlePage

Authors: Qing Dun Zeng, Fang Liu
Abstract: Various new type scaffolds have been introduced and developed in China. They are novel in structure and economic in material, but their security and reliability can not be ignored. This paper introduced a new chained formwork support frame with nine upright tubes and many cross-braced connections. Firstly, the load test of the support frame was performed in order to observe the failure process and to determine the ultimate bearing capacity. Then, the strength and stability of both single upright tube and a cross-braced rod were checked according to the existing specifications on scaffolds. Finally, a finite element software ANSYS was used to establish a solid model for the support frame. The structural stability was analyzed and the ultimate bearing capacity was calculated. The comparison between the computational and experiment results was carried out. The results show that the ultimate bearing capacity of the new chained formwork support frame is controlled by the structural stability.
1449
Authors: Qing Dun Zeng, Fang Liu
Abstract: According to an example of the broken jib accident of a high pedestal jib crane (HM2564) in a Shipyard Co., Ltd. in Guangdong province, this paper used a finite element software ANSYS to establish a solid model for the jib frame of the crane, calculated the stresses of jib system under various actual working conditions and checked the strengths. Simultaneously, the reasons of broken jib were quantitatively analyzed from the perspective of mechanics. The results show that the strengths of the jib system meet the requirements of safe use under all kinds of working conditions, but the related hoistman incorrectly operated the facility, cables can’t be winded normally in pulleys, thus resulting in that the tensile force of a cable was directly applied on the main jib by pulley spindle and the failure of the jib frame occurred under heavy compressive force of lifting cables.
322
Authors: Qing Dun Zeng, Mao Hua Ouyang
Abstract: On the basis of the shear-lag theory, an analysis was presented for stress redistributions of cross-ply laminates with a transverse matrix crack in the 90º ply under bending by establishing a layered shear-lag model. The present results show that approximate solutions of displacement and stress distributions for cross-ply laminates with a transverse crack under bending can be obtained by using a shear-lag method. The present paper therefore affords a new approach for studying the stress redistributions and failure mechanism for cross-ply laminates with flaw under bending.
492
Authors: Qing Dun Zeng, Mao Hua Ouyang
Abstract: On the basis of the shear-lag theory, a layered shear-lag model was established to study the stress redistributions of cross-ply laminates with multiple transverse matrix cracks in the 90º ply under bending. The present results are in a good agreement with variational solutions and finite element results and show that approximate solutions of stress distributions for cross-ply laminates with transverse cracks under bending can be obtained by using a shear-lag method. The present paper therefore affords a new way or method for studying the stress redistributions and failure mechanism for cross-ply laminates with flaws under bending.
256
Authors: Qing Dun Zeng, Meng Hua Qiao
Abstract: In allusion to the safety problems of the shippment structure of hull subsection at area B in a Shipyard Co., Ltd., Guangdong, in this paper, a solid model for a proposed shippment structure of hull subsection was established by using a finite element software ANSYS which is a common software, the internal force (stress), deformation and stability of components under various actual working conditions were calculated, and then the checks of strength, stiffness and stability were performed on the basis of the national regulations. The results show that both strength and stability can meet the safety requirements of operation, but stiffness is insufficient, because the horizontal displacement of steel pillars in shippment structure oversteps the specified value of the national standards of China. The conclusion provides a theoretical foundation for the safety use of shippment structure of hull subsection and the optimization and improvement of the structure.
1019
Authors: Qing Dun Zeng, Yong Lu Zhou
Abstract: In order to reveal the failure properties of AFRP sheet-reinforced beams under 4-point bending, a 3-D finite element model of RC beam, including rebar, interface and sheet elements, was established by using MIDAS FEA finite element software. The stress and displacement of each of components in beam were solved by cycling calculations. In terms of Code for Design of Concrete Structures, the initial cracking loads of RC beams strengthened with prestressed and non-prestressed AFRP were further obtained, which are relatively conformed to the existing experiment. The results show that, compared with the beams strengthened with prestressed and non-prestressed AFRP, the initial cracking load of the former has considerable increase.
1
Authors: Qing Dun Zeng, Feng Zhe Tan
Abstract: The main content of gear design is the strength design, and the contact strength design of gears is the main heart of the strength design, because the stress and deformation of gears directly affect their safety and service life and concern whether vehicle transmissions work smoothly. Therefore it is necessary to perform a finite element analysis for the gear contact in transmission. Based on the contact characteristic of helical gears, a three-dimensional solid model was established by using the software Pro/E, and the contact stress analysis of gears was carried out by the software ANSYS Workbench. The stress and strain distribution contours of helical gears were obtained, and then the check of shtrength and rigidity was performed. Thus, it is convenient for designers both to test the strength of gears and to modify the size of gears.
443
Authors: Qing Dun Zeng, Xin Pan
Abstract: The joint simulation of Virtual Prototype Technology and Finite Element Method was utilized to perform the analysis of both strength and fatigue life of the input axis in a six-speed vehicle transmission with three axes. Firstly, the software Pro/E was used to establish a 3-D model of the input axis and its gear engagement, and the model was then imported into a software ADMAS of the virtual prototype technology to perform a dynamic simulation analysis. Secondly, the gear contact forces obtained by above-mentioned analysis were used as the loading condition of finite element analysis of the input axis to check its strength. Finally, the fatigue of meshing teeth on the input axis was analyzed to determine the fatigue life of the input axis. The results show that the static strength of input axis can meet the requirement of safe use under the working condition of input torque T=1.5kN·m, and the minimum fatigue life on the place where the stress is maximum at flexural root of a tooth is about 2 million times.
45
Authors: Qing Dun Zeng, Qin E Li
Abstract: The strength and stiffness characteristics are important parameters in the design of metal structure of gantry crane. In this paper, the modeling of a gantry crane before and after reconstruction was performed by using Finite Element Method, and the strength and static stiffness of the gantry crane were analyzed. The results show that the insufficient stiffness of the reconstructed gantry crane in the shaking direction causes its laterodeviation. A strengthened method was determined after comparison of four reinforcement measures. The present results can provide an importantly theoretical basis for the reconstruction or strengthening of gantry cranes.
3077
Authors: Ling Ling, Qing Dun Zeng, Gui Yuan Wang
Abstract: On the basis of the analytical methods of composite mechanics, a layered shear-lag model was established to study the shear stress distributions of the interfaces between concrete and adhesive layer as well as adhesive layer and fiber sheet or steel plate for fiber sheet/steel plate-reinforced concrete beams with cracks under tension and bending. The results show that the properties of strengthened materials have some effects on the interfacial shear stress. The level of interfacial shear stress increases as both the length of cracks and thickness of fiber sheet or plate are increasing. The influence of crack spacing distance and thickness of adhesive layer on normalized interfacial shear stress is relatively less. The axial tensile force has some impacts on the interfacial shear stresses.
61
Showing 1 to 10 of 12 Paper Titles