Advanced Materials Research Vols. 753-755

Abstract: Combination of ice blasting model is set up with the program of blasting with technology of shaped charge, numerical calculation is carried out, and the shockwave peak pressure in ice medium is obtained based on the large-scale finite element software ANSYS/LS-DYNA . This paper analyzes the stress distribution of ice in the combination of underwater explosion loads, and studies the process of the underwater explosion. The article aims to promote the application and research of underwater explosion in Yellow River and Hei Long Jiang River ice blasting, etc.

Abstract: The dipper handle is most important to design and manufacture as the main component of excavator. That many fracture accidents lead to great losses. So it is necessary that study influence of the impact to service performance. In this paper the FEM is used to analyze dipper handle to find out the weakness in the structure. The improved dipper handle was used in the device and inspected by handle test. The stresses are measured in some conditions and the results were also in consistence with the theoretical analysis. Improved 3D model is rebuilt using the ANSYS to recalculate the stress. Since the improved dipper handle was used in practice to now, fracture accidents have been not happened again.

Abstract: The strength and stiffness of humanoid massage robot arm are the main factors that they affect the dynamic characteristics and positioning accuracy under the action of the load. In order to analysis the strength and stiffness characteristics of humanoid massage robot arm. With SolidWorks we establish parametric model and by finite element analysis software ANSYS analyses the strength and stiffness of key parts and components. Emulational results show that the stiffness and strength of humanoid massage robot arm that we design and invent meet the design requirements, lay a foundation for further optimization design.

Abstract: The dynamic of a type of play equipment, Big Pendulum Hammer, was modeled and simulated in computer and the approach of natural coordinates was adopted to build its equation of motion. In order to obtain appropriate natural coordinates, a two-step selection method was chosen, which based on concept of natural coordinate system (NCS). The two-step method treats selecting natural coordinates for a rigid element as building an actual NCS which should be adapted from a standard NCS. In order to automate the process of adaptation for 18 rigid elements in the model of Big Pendulum Hammer, a four-step self-adaptation method was also adopted, which can help automate the selection of natural coordinates for multi-rigidbody systems.

Abstract: Thermal deformation is a common phenomenon of thermal effect which has great influence to the accuracy of measurement. It is well-known that the dimension of components changes in corresponding to the variation of physical temperature. Traditional thermal deformation theory and calculating formulas are approximately applicable to the components of low or general precision requirement, but not to the requirement of high precision or modern nano-scale field. Traditional linearity formulas of thermal deformation only correlate to their own dimensions, which offers no enough accuracy. In real world situation, thermal deformation of any dimension is the function of interrelated dimensions. To correctly constitute mathematic model which reflects the effects of the body parameter to the thermal deformation has great significance in both research and application communities. In this paper, by constituting GM(1,1) of linear thermal expansion and putting in GM(1,2) of the effects of the parameters of the components, we can prove the effectiveness and the feasibility of gray model in treating the thermal deformation of body physical parameters.

Abstract: Comparing to oil transformer, the dry-type transformer minimizes explosion and fire hazard, as well as long product life. Meanwhile winding insulation plays an important role in the reliability, yet winding temperature rise may cause deterioration to the insulation. So it is critical to have temperature rise analysis for hot spot and prediction in the period of prototype design using finite element method, such as CFD. The key factors like completed boundary condition and coupling of electro-magnetic with thermal fluid will be obtained from experiment which could provide more accurate heat transfer coefficient for new design. Relative to method of thermal network, CFD has provided more accurate air convection model and different boundary condition definition, thus it could be an original data for other serial product simulation.

Abstract: To effectively excite the all moving wing flutter model and limiting or quick locking model in case of bigger amplitude of the model, an excitation and limiting and locking device is designed for the high-speed wind tunnel flutter test model. This paper introduces the structure arrangement, control principle and strategy of this device. The wind tunnel flutter test indicates that this device can enhance the SNR of the test data, improve the boundary prediction precision of flutter, prevent the model from entering the flutter divergence state and protect the model and wind tunnel test equipment.

Abstract: Shrink fit is an important method used to connect mechanical parts but less studied by three-dimensional finite element method. Based on the theories of induction heating and thermal conductivity, we established a three-dimensional FEM. The model included the induction coil, crank throw and air. The pattern of temperature field distribution during the period of induction heating were numerically simulated with software ANSYS .The simulation showed that, crank throw can obtain a uniform temperature field around the hole after induction heating .As a result, the crankshaft reaches a highquality shrinkage fitting, manifesting the feasibility of the application of induction heating to the crankshaft shrinkage fitting.

Abstract: This paper presents an improved experimental equation for representing wave spring behaviors. Wave springs were widely used for automobile automatic transmission and have to be precisely controlled. In fact an experimental equation was provided by mechanical design handbook. However the accuracy of the equation is not suitable. Therefore we tried to optimally modify correction factor K used in the equation without modifying the whole equation. For this different models of springs were manufactured to test and simulate. Theses results were analyzed and redefined correction factor K. To evaluate the proposed approach modified correction factor K was applied into various models and good agreement was obtained.

Abstract: A synthesized simulation process was used to predicting temperature and high cycle fatigue (HCF) of cylinder head in this paper. Firstly, the temperature prediction model was built and calibrated by the test data, which ensured the rationality. The simulation result shows that the material thermal conductivity is very low and the position of the drilling holes near the deck is very high, and the thermal load was reduced effectively through improving the material conductivity and optimizing the structure design. Finally a fatigue life evaluation has been performed which shows the HCF safety factor is higher than the original design due to the temperature reduction.