Applied Mechanics and Materials Vols. 353-356

Abstract: The channel steel connectors of novel prefabricated prestressed concrete beam play an extremely important role in structures. They act as the connectors of prefabricated beams and columns and support the prefabricated beams temporarily at construction stage, work as shear connectors of the adjoining faces between the old and new concrete at using stage. But they are easy to be bond slip failure for its complicated stress states. To analyze their mechanical behavior and failure mode, the interaction between concrete and channel steels is considered by adopting the spring unit and nonlinear analysis with finite element software ANSYS. The results indicate that the channel steel connectors of novel prefabricated prestressed concrete beam are effective in bearing various loading effects and meet the requirements of prefabricated structures.

Abstract: Deep foundation pit supporting in soil-rock areas has been occurred commonly in Dalian. In the dual structure deep foundation pit in which platform is reserved, pile-anchor support as a typical form of foundation pit support, how to play its role effectively and make the design economical and safety is the subject which was explored continuously in recent years. Through a practical engineering case, this paper will use finite element software ABAQUS to simulate the whole process of pit excavation. Simulation results show that the boundary of the dual structure is the key position that caused the “sharp deformation” of the supporting structure. Compared with monitoring data, the results indicate that the reliability of the numerical model and the relevant deformation laws are verified, which can be used for the reference for the design, construction and monitoring of the deep foundation pit support in the similar location.

Abstract: The shaft drilling diameter is up to φ7m, Larger borehole and deepened section make slow drilling problem more and more prominent, which has seriously affected the drilling cost and drilling cycle, thus affecting the exploration and development speed of entire coal mine and the oil field. At present, the improvement of drilling speed and efficiency of φ7m and larger diameter section has become a technical problem needed to be solved. In order to improve the drilling speed of φ7m diameter and larger diameter boreholes, super twin-stage bit is recommended. It has an enlarger drill (φ 4.5m) than average bit using twin-stage structure.,A small guide hole is drilled the first, followed by drilling the borehole. On the other hand, the stratum drilled makes larger free surface to release the ground stress, which will increase ROP, reduce drilling time and quicken the speed of well completion.Starting from the mathematical model of stress field and velocity field, this paper establishes the unit models of bottom-hole stress field and velocity field. Through the finite element analysis, it analyzes influence of different slurry suction port position on rock breaking efficiency, which has high reference value for the design of super twin-stage drill bit.

Abstract: This paper investigated the flow structure in liquid bridge of high Pr Number fluid under zero gravity condition. The free surface deformation and the effects of gas phase around liquid bridge were considered. Navier-Stokes equations coupled with the energy conservation equation were solved on a staggered grid. The two-phase surface was captured by using the mass conserving level set method. The results indicated that location of vortex center move gradually toward the free surface due to thermocapillary convection. The flow velocity nearby the surface of liquid bridge is faster than the internal flow velocity, and the overall velocity level tends to decline with time evolution.

Abstract: This paper is based on the basic principles of the extended finite element in the large commercial software ABAQUS on the platform of different fracture energy of three point bending test of concrete are numerically simulated, and three-point bending crack initiation, through expansion path analysis. The results show that has a direct impact on the size of the fracture energy of concrete specimens destruction, Fracture of brittle fracture can be small more obvious, produce more harmful. When softening decline stage after peak stress occurred in the "jump back" phenomenon.

Abstract: To provide with an effective method for non-photorealistic rendering for computer generated images with sketch artistic appearances from 2D images motivates our work in this paper. The character of lines, details in the source image can be smoothed by the technique of guided filter, and then the abstract smooth appearance of the image can be simulated. In addition, the smooth effect can be enlarged and enhanced by the technique of improved line integral convolution, so the final sketch artistic image can be obtained. Experimental results show that the proposed method can simulate the real sketch effect.

Abstract: Gypsum walls are a green product that helps to save energy and protect the environment. This paper numerically investigates the effect of axial load on shear strength of glass fiber reinforced gypsum (GFRG) walls fully or partially filled with concrete in the hollow cores. The conclusion drawn in this paper is general and applicable to other kinds of walls.

Abstract: The gas-power flow resistance-controlled electromechanical switch was a kind of new gas-driven piston-style electromechanical switch used in fuze. It was designed with a flow resistance adjust automatically structure based on the structure of flow resistance-controlled switch. This kind of new switch could adapt to the press change of the input gas to guarantee the stability of the piston movement, and with the piston to the end to turn the switch to achieve the purpose of electronic delay. Firstly, the gas dynamics model of the switch was made according to the structure, Secondly the change of internal gas state and the process of the piston movement were calculated when the rockets was in ballistic phase. Finally, with the similarity model of the switch and digital simulation, the stability of the piston movement and automatic adjustment feature was analyzed.

Abstract: Traditional Construction Engineering education has some shortcomings, such as difficulty to clearly show complicated structure, high cost and period limitation of practice teaching. So the 3D Construction Engineering Teaching System was built based virtual reality (VR). The system was according to real building and integrated many main courses. The system realizes virtual tour, real-time interaction and shows all architectural and structural features by dividing layer and layer. The experiencing model can stimulate students' interest and achieve remarkable effect. Moreover, this puts forward a new idea of curriculum integration for Construction Engineering Training Program. The developmental model based on ProE, 3D MAX and Virtools supplies a new way to research virtual teaching system. The key technology and solution also fit general 3D interactive simulation system.

Abstract: This thesis took the Changshan Bridge in Dalian Changhai county as an example and adopted the general finite element software ANSYS to simulate it. Analyzed the stability of the completed bridge and the single free-standing tower state, and studied the buckling of the main girder and the thin-walled pier.