Applied Mechanics and Materials Vol. 470

Abstract: Considering the fact that the oil well conditions of LIAOHE oil field, the existing structure of the forced lifting and pushing system of work over rig is improved. Main drive gear pair of the forced lifting and pushing system improved is established to study the intensity of contact and modal in the operating process and the dynamic loads based on finite element method. Main failure forms in the condition of low speed and heavy duty is deduced from the distribution of the stress. Also, the maximum allowable stress and natural frequency is obtained. According to the simulation making use of ANSYS, a 3D contact stress analysis of several teeth and modal analysis in dynamic pre-stress of full teeth is illustrated with the rationality of the design.

Abstract: The change of moisture-heat is the key factor that influences the seasonal freezing subgrade stability. In order to analyze the impact of the moisture on temperature field in the seasonal frozen subgrade, this paper established seasonal freezing subgrade model, calculated and analyzed the effects of subgrade temperature field in the middle of road, shoulder, slope and outside of slope with roadside accumulated water, based on the change of temperature field control equation. This research showed that roadside accumulated water has a significant influence on the subgrade temperature field. The results showed the range of 0°C isotherm under the accumulated water was bigger than normal subgrade, and the depth of 0°C isotherm was deeper under the accumulated water than normal.

Abstract: Shape Memory Alloy (SMA) composites are being used in an ever-expanding set of applications. For new applications, SMA composites are being developed as metal-ceramic Functionally Graded Materials (FGMs) utilizing SMA as the metallic phase, which contain both high temperature resistance of the ceramic phase and the mechanical properties of SMA composites. Three models including Averaging Technique of Composites (ATC), Mixture Rule (MR) and Mori-Tanaka (MT) scheme are used to calculate the stress distributions of the system subjected to thermal loading, respectively. The results obtained from the analyses of an SMA-ceramic graded composite show that after transformation the stress in the SMA composite is lower than in the case of pure elastic composite under the same thermal loading. This decrease stress can result in an increase in temperature resistance and improved mechanical properties of SMA composites. This work will be explored through a parametric study to understand their influence on SMA composite design.

Abstract: In order to study the effect of oxygen-enriched combustion on the performance of exhaust emission of diesel engine, the 4jb1 diesel engine is taken as the research object and kiva-3v program was used to simulate the oxygen-enriched combustion progress by changing the concentration of oxygen and the concentration of carbon dioxide in the intake. The result showed that with the increased of carbon dioxide concentration, the ignition delay period was shorten and the rate of heat release rate was reduced effectively, the average pressure and the average temperature in cylinder were reduced and the emission of nitrogen oxide can be controlled effectively under the condition of oxygen-enriched.

Abstract: The settlement of immersed tube tunnel is mainly caused by the compression of basal layer and recompression of the ground foundation layer. Defining the composite foundation as a combination of basal layer ofimmerse tube tunnel and ground foundation layer, a three-parameter model is proposed in this study to simulate the composite foundation in which the basal layer was represented using springs and the ground foundation layer by Kelvin’s model. Based on the solution of beam on elastic foundation, analytical solution for settlement of immersed tube tunnel using the proposed three-parameter model was derived by means of Laplace transformation according to the correspondence principle and the constitutional relationship of the three-parameter model. Initial and final settlement as well as variation of settlement in terms of time were calculated and compared with the actual measured data in combination with actual data measured during tunnelling of Shenjiamen immersed tube tunnel in Zhoushan City. Results showed that the proposed three-parameter model is capable of replacing the basal and ground foundation layers. The calculated value matched favourably with the actual measured value and the variation of settlement in terms of time for immerse tube tunnel can be represented.

Abstract: Software Failure Modes and Effects Analysis (SFMEA) technology is the most common technique in reliability and safety analysis. The common software FMEA methods are summarized and for object-oriented software, combined with the Rhapsodys characteristic of modeling and simulation, we proposed the SFMEA method based on modeling and simulation by Rhapsody and gave the process of implementation, the acquisition methods of failure modes and the SFMEA example.

Abstract: A series single-pass compression tests of HRB400 slab under the circumstances of different deformation temperature and deformation rate are carried out with Gleeble-1500D thermal simulation testing machine. The experimental results shows as follows. The true stress-true strain curves of the compression process are got from the tests. The state activation energy is 353.542kJ/mol and a mathematical model of high-temperature rheological stress is established. The calculated results by the rheological model are consistent with the experiments.

Abstract: Based on the non-linearization of hydraulic cylinder controlled by servo valve system, the system mathematics model was difficult to be deduced. In the paper, by combining the rich model base of AMESim with Powerful function of numerical calculation of Matlab software, combined simulation for two softwares was presented. The simulation results were virtually the actual work conditions; also it provided better reference value for the next experiment research.

Abstract: A three-dimensional entity model of storage grid semi-trailer frame was designed using the Pro/E software. The model was transferred into the ANSYS for static strength analysis. On this basis, bionic structure was introduced into design of semi-trailer frame. The static strength of bionic and traditional structure was contrasted under the same conditions of weight.

Abstract: The coupled thermo-flowing 3D steady-state model of friction stir welding model is established based on fluid mechanics. With analyzing the impact of pin shoulder and pin on heat producing, the model considers the influence of pin on the heat producing processing. The model applies viscoplastic constitutive equations to describe the material, and turbulence model to simulate the material flowing behavior. With the additional turbulence kinetic energy equations and flow boundary condition equations, the model is established. With Comsol Multiphysics finite analysis software, a process simulation was carried out, and the results reflect that the model can reveal the steady state characteristics of thermo and material flowing behavior of friction stir welding.