Applied Mechanics and Materials Vols. 599-601

Abstract: Based on the mixed finite element method ，simulated the horizontal well fracturing complex artificial fracture. The article use line elements to describe the horizontal well bore, arbitrary triangle elements to describe the formation. To influence the fracturing horizontal well productivity of artificial fracture parameters are optimized, including the number and fracture length. For different fracture parameters of production dynamic curve carries on the contrast analysis, obtained the different fracture parameters of pressure profile and saturation profile. Research shows that the crack amount and crack length of horizontal well fracturing production dynamic all have obvious influence, but not the bigger the better, there exists optimal value.

Abstract: Regarding 20 tons hydraulic excavator boom in an enterprise as the research object, the boom volume was set as an optimized object. According to the dynamic simulation analysis of working device in typical working conditions, constraint conditions including the maximum stress, displacement range and thickness variable ranges of each steel plate, were determined, and the thickness of twelve primary steel plates of boom were selected as design variables. A lightweight design scheme has been developed through the optimization module in ANSYS software, which could decrease the boom weight by 9.7% and the strength and stiffness of optimized boom structure also met the design requirements.

Abstract: Many difficulties may be encountered when preparing CNC programs using conventional programming or canned cycle programming. This study tries to establish a practical common algorithm allowing the drilling of holes arranged in multiple circular patterns. The programmed algorithm can easily be adapted to any modern CNC unit to create a user cycle or subroutine. To test the capabilities of this algorithm, two case studies were developed. A number of samples were produced successfully. The new algorithm shows high efficiency in the part program establishment and offers the advantage of decreasing the encoding errors.

Abstract: Correction machine gun finite element model to predict dynamic characteristics is very important. Through theoretical calculations and experimental test structure to obtain guns frequency response function, given the sensitivity of both the correlation function and expression, introduced a model correction method, and laid the theoretical foundation for a certain type of machine gun finite element model updating. Build a certain type of machine guns and modal testing and analysis system was carried out to test the vibration frequency response function. Boundary condition parameters of the machine gun was amended, and modal test results were compared to prove the validity of the model correction method.

Abstract: This paper established a nonlinear model of a turbofan engine by modularizing the components. It selected and key section parameters and to carry the numerical simulation through. The calculated results which achieved by the computer were compared with test data. It shows that the results meet the accuracy requirement. And it also provides the means to establish the engine half-physical simulation test platform.

Abstract: A design method of modular joint is proposed according to the complicated structure, line exposed and heavier characteristics of multi-DOF (degree of freedom) mechanical arm. In this paper, the design of modular joint was carried on and a model of six-DOF mechanical arm was built through the research on the structure of mechanical arm. On this basis, dynamics simulation will be carried. The results show that the modular design method simplified the structure of the mechanical arm, the dynamics simulation proved it was feasible for the structure design and drive selection.

Abstract: A framework for solving the multi-objective optimization problems of spring in multidisciplinary design environment is advised in this paper. Based on the collaborative optimization (CO) algorithm, a new system level objective function is advised to minimize relative value among the structural mass, the height and the natural vibration frequency. The proposed models were demonstrated with a multi-objective optimization problem of a spring. The optimal design of the spring obtained indicates the great potential of decreasing structural mass and vibration level and increasing natural frequency reserve under the constraints. The analysis progress and results show that the model is feasible and well-suited for using in actual optimization problems of spring design.

Abstract: Using blade tip winglet to control the tip leakage flow has been concerned in the field of turbomachinery. Computational simulation was conducted to investigate the phenomenological features of tip clearance flow. The simulation results show that suction-side winglet can reduce leakage flow intensity. The tip winglet can also decrease tip leakage mass flow and weaken tip leakage flow mixing with the mainstream and therefore reduce the total pressure loss at the blade tip.

Abstract: Steinberg failure models based on Mott distribution in ANSYS/LS-DYNA was used on the formation of fragments.The forming process of the fragment damage field of the shell was simulated. The mass distribution、spatial distribution and the attenuation law of initial velocity of fragments are analyzed. The shell damage-field may serve as a basis for the future research on power of shell fragment to the targets.

Abstract: The numerical simulation calculation of air-assisted atomizer internal gas flow field is done, the distribution and changes of the nozzle inside flow field total pressure, velocity, and dynamic and static pressure are analyzed. The analysis shows that the total pressure loss is less; due to the effect of gas viscous, the high-speed air flow is formed vortex flow near the outlet nozzle and the mutual influence between the dynamic and static pressure. A new way is supported for optimizing the nozzle structure according to these studies.