Advanced Materials Research Vol. 716

Abstract: The working condition of the spin-flash dryer agitating blade is complex, and influencing factors of the blade strength are quite more. In order to research its mechanical properties under the condition of transient high temperature, the analysis of thermal structure coupling field was performed. By the analysis of thermal stress and thermal deformation, the agitating blade would be designed well.

Abstract: Structure health monitoring system is used to monitor structural responses in real time. Dynamic performances of subway station structures are help to analyze seismic performances of the structures. Through structure health monitoring system of a subway station structure, dynamic responses of the subway station structure were tested under railway loads. The dynamic strain and internal forces of subway station structure are obtained. As restrained by earth, dynamic responses of the subway station structure is not significant change from most surface structures. Wavelet and multiscale analysis can be a powerful tool for multiple decomposition of potential fields data. Wavelet analysis can eliminate the noise for a clear data. The main train induced vibration frequency is also acquired through the method of wavelet analysis.

Abstract: Selected ductile fracture criteria are introduced and applied to prediction of chevron crack initiation and development during forward extrusion of long shafts. We present the calibration of selected criteria for carbon steel, simulate the process of forward extrusion and compare the simulation results with real experiments realized in a cooperating industrial company.

Abstract: A method to simulate rolling contact wear in a rail surface was developed using the finite elements method and numerical analysis. A two-dimensional finite elements model was used in order to reduce the calculation time and boundary conditions to prevent excessive deformation of a wheel and a rail were applied. A numerical analysis of rail wear at rolling contact was predicted using the Archards equation. In addition, the characteristics of rail wear with the increasing speed of vehicle were analyzed. Results show that there was not a large difference in the depths of wear on the rail head with increasing vehicle speed, but the wear on the rail gauge corner increased with increasing vehicle speed.

Abstract: A new structure of oil screen named self-energizing oil screen with dynamic filtration rollers based on gear train was put forward. It uses the pump inlet fluid kinetic energy which is produced by pump working stroke to drive the impeller to rotate. The driving moment is transmitted to the rollers by means of gear train. When the rollers rotate, sands are prevented and oil is filtered. Computational model of the screen was established by GAMBIT based on the computational fluid dynamics. The velocity filed and pressure field distributions were attained and the driving moment of the screen was computed by FLUENT solver. The results validate that the new designed self-energying oil screens structure is reasonable, it can filter the oil effectively when the pump works.

Abstract: A Soft bending pipe is widely used for freezing equipment and shipbuilding. This pipe has some problems such that outside wrinkle, crack, phenomenon of thinning wall. However, the bending machine that can completely solve the problems is not yet. In this study, we have manufactured the self-made mandrel to guarantee both roundness and thickness of the pipe in the bending process for a soft pipe such as a copper pipe. The mandrel consisted of a ball, stick and connection pin. Also, we have manufactured the bending machine that can decrease friction between the pipe and the bending die. The experiment was tried to verify the performance of the mandrel and the pusher to the thickness guarantee of the pipe.

Abstract: The interior noise samples from four cars at different positions and different speeds were selected as the evaluation objects. The subjective evaluation test of sound quality preference was carried out with paired comparison method. Several objective psycho-acoustical parameters of these samples were calculated. By way of linear correlation and multi-dimensional regression analysis, an equation between the subjective evaluation of noise preference and the objective psycho-acoustical parameters was established. The results indicate that the vehicle interior sound quality preference under the good highway and the constant-velocity driving conditions is affected mainly by two psycho-acoustical parameters Loudness and Sharpness.

Abstract: Large deformation problem under dynamic loading has been an issue for mechanical engineer and researcher who study continuum mechanics because of its complex behavior. This study focuses on a large deformation problem based on nonlinear viscoplasticity. Therefore, the Johnson-Cook constitutive model and the Zerilli-Armstrong constitutive model are used to analyze and to understand this stretch example under dynamic loading. Numerical results for stretch example using both constitutive models were compared with the results from ABAQUS/Explicit that considered mesh sensitivity analysis, and were then applied to model failure processes of OFHC copper, with consideration of geometric nonlinearity based on concepts of progressive damage mechanics. This approach helps us to understand and to predict the behavior of large deformation and to perform damage failure analysis.

Abstract: The artificial ground freezing (AGF) is now widely employed in constructions with the expanding underground space exploitation in Shanghai. In order to avoid geological disasters which might appear in the AGF practice, it is urgently needed to do laboratory tests on the physical and mechanical characters of Shanghai soft soil under freezing and thawing action. This paper tests three kinds of soils from the location ofShanghai Metro line 4 constructions in different state, i.e. original state, freeze-thaw state and secondary freeze-thaw state, and obtains the changing rules of soil characters under secondary freeze-thaw action.

Abstract: About under-group coal seams mining with the threat of high-pressure ordovician water, conventional mining technology by draining depressurization usually causes environmental issues such as soil erosion and ground subsidence etc.,By using grouting reinforcement technology, this paper changes floor direct charge layer into relatively separatedwater layer in the coal seam and achieves the goals of sealing the water inrush channel, moreover, on the basis of coal floor failure depth analysis and monitoring, the paper evaluates risk of water-inrush from seam floor when face length increases, On this basis, puts forward a reasonable working face length and mining technology, and has abtained good economic and social benefits in practice.