Advanced Materials Research Vols. 791-793

Abstract: In process of Thermal Wave NDT, as a result of influence from kinds of factors, such as noise, intensity of heating signal, defect dimension, it is very difficult to get good testing data. In order to resolve it, the method of numerical computing was taken to simulate the process of heat conduction in sample. At the simulating process, some valuable phenomenon were found, and as follows: When time of heating time was enough, temperature changing at surface would be steady, and rate of changes could be approximately considered as a constant; the biggest contrast would delay, as depth and diameter increased; the greater intensity of heating signal was, the quicker change of contrast was; and it was more important to ascertain the best testing time when the biggest contrast occurred. And these were valuable to acquire more precise testing result.

Abstract: The composite of carbon fiber reinforced polyethylene resin was prepared by using a twin-screw extruder. The effect of carbon fiber oxidation treating on the mechanical properties of carbon fiber reinforced polyethylene resin composite was researched. The tensile fracture failure mechanism of composite was analyzed for both untreated and air oxidation treated specimen. The experimental results indicate that when carbon fiber content is equal, the tensile strength and the elastic modulus of air oxidation-treated carbon fiber-reinforced polyethylene composite are improved than that of the untreated. When the fraction of adding carbon fiber is 3.99%, compared with the pure polyethylene resin matrix, the tensile strength, elastic modulus is increased by 13.12% and 172.91%, respectively. Compared to the untreated carbon fiber reinforced polyethylene resin composite, the tensile strength and tensile modulus is increased by 4.71% and 13.14%, respectively.

Abstract: This paper uses time-history analysis method to consider the effect of 3 kinds of seismic waves by means of finite element software Ansys, analyse earthquake response of 5 kinds of models, compares effect of structural performance of frame structures with different types of stairs. The results show that different types of stairs diversely affects period, stiffness, mode of vibration, mechanical performance, etc, after consideration of stairs in calculating. Although types of stairs different, it shows mainly that stairs make much larger contribution for stiffness parallelled to stairs, less contribution for stiffness perpendicular to stairs, each layer just affects stiffness this layer. It is not simple to consider different types of stairs as general supports.

Abstract: Based on the reversed cyclic loading test of three 1:4 high-strength concrete flat columns, the computer program ABAQUS was used to simulate behaviors of the specimens. Concrete in the column was modeled using the damage plasticity material model, and a uniaxial steel model with combined isotropic and kinematic hardening properties was used to simulate the behavior of the reinforcement. The establishment of the finite element model, definition of the material parameters and the influence of diagonal reinforcement were discussed at length. The results show that the concrete damage plasticity model can be well used for hysteretic analysis of reinforced concrete members if the relevant parameters are reasonably defined. Diagonal reinforcements can not significantly improve ductility of the specimens, but can improve their shear capacities. This paper can provide reference for the performance simulation of reinforced concrete members under cyclic loading.

Abstract: Through the analysis and research on the microstructure and phase diagram of copper matrix composites, by use of collage method to approximate graphite particle and silicon dioxide particle, combined with statistical method analyzing some statistical characteristics of graphite particle and silicon dioxide particle .On the basis of the result that have been get in this paper, microstructure and phase diagram of copper matrix composites was simulated by taking advantage of direct Monte Carlo method.

Abstract: In aerospace engineering, seal is an important component of manned spacecraft life-support system. The pressurized tube sealing equipment is designed, and the experimental system of principle leak-rate of pressurized tube is built, and the experimental theory of the principle leak-rate of pressurized tube is carried out. The experimental results show that leak-rate of pressurized tube is related with the internal pressure of pressurized tube, and sealing ability can be adjusted by controlling the pressure in tube. And leak-rate of pressurized tube is involved with sealed pressure differential, and the bigger pressure differential is, the larger leak-rate becomes. And pressurized tube can fit for big structure transfiguration, which provides condition for lessening structural weight. And the pressurized tube can meet the demands of sealing of space station.

Abstract: During forging of as-cast for fractured connecting rod, the key is to determine heating temperature and to control cooling speed after forging. They two points are correlated with each other. To assure metal fluidity in the course of striking and forging, fillet should be enlarged at transit between ribs and web. Wrought parts shall be subject to normalizing by residual heat from forging process. Its metallographic structure consists of pearlite and ferrite. Content of ferrite should not exceed 35%. In addition, it should be such that the fraction for volume of ferrite get bigger and grain should be greater and evenly distributed.

Abstract: Accurate calculation of rock mechanics parameters is of great significance in developing comprehensive drilling and oil/gas development programme and technical measures, as well as reducing operation risk. It greatly relates to the reliability of ground stress field numerical calculation. This paper proposes a new method for calculation of 3D rock mechanics parameters, on the basis of acoustic logging data and lab core test data and also by reference to seismic velocity field. Taking Keshen 2 area in Tarim Basin as example, we have calculated 3D rock mechanics parameters using VB.NET calculation program, and drafted 3D rock mechanics parameters cloud charts of some profiles, showing small discrepancy against the acounstic logging interpretation data of production well. These 3D rock mechanics parameters calculated in this method can be directly applied for numerical calculation of ground stress field, providing references for fracturing parameter design and improving the simulation of reservoir stress field.

Abstract: The cored wires were fabricated using five kinds of amorphous compositions with high Fe content. The cored wires were sprayed to form coatings by high velocity arc spraying (HVAS) after optimizing technology. We studied the bonding strength of the coatings. The results are as follows: combining ways between coating and substrate are mainly mechanical combination. The average bond stress is above 30 MPa.

Abstract: Turbulent fluidization is a flow regime between bubbling fluidization and fast fluidization. The influence of static bed heights and axial locations on transition velocity was studied from bubbling fluidization to turbulent fluidization in a 368 mm×368 mm square fluidized bed, based on the pressure gradient fluctuation by measurement differential pressures transducer of FCC. Experiment results show that the transition velocities increase with decreasing location of observation or increasing static bed heights. And the transition of regime from bubbling fluidization to turbulent fluidization is a process gradually happened from the upper to the lower bed section and is not instantaneous behavior in the whole bed. Based on those, the prediction model is built that the average solids concentrations of bed cross-section are used to reflect the variation of gas-solid interaction along the bed height. The new prediction correlation by fitting parameters of experimental data is in well agreement with experiment results