Applied Mechanics and Materials Vols. 397-400

Abstract: Digital displacement fluid power pumps/motors offers improved efficiency and performance compared to traditional variable displacement pump/motors. These improvements are made possible by using efficient electronically controlled seat valves and careful design of the flow geometry. To optimize the design and control of digital displacement machines, there is a need for simulation models, preferably models with low computational cost. Therefore, a low computational cost generic lumped parameter model of digital displacement machine is presented, including a method for determining the needed model parameters based on steady CFD results, in order to take detailed geometry information into account. The response of the lumped parameter model is compared to a computational expensive transient CFD model for an example geometry.

Abstract: The pressure regulating valves are crucial segments to control the pressure of the stability chambers in the transonic and supersonic blow-down wind tunnels. To solve the valves vibration problem, the pistons and their supporting structures of three typical pressure regulating valves in China Aerodynamics Research and Development Center (CARDC) were analyzed based on the modal analysis theory. From the analysis, two conclusions were obtained that the supporting structures are more rigid than the pistons, and a rigid piston is of critical importance to the valves stiffness. The structural parameters comparing results of the pistons showed the same viewpoint. A new design pressure regulating valve demonstrating the successful application according to the conclusion above was presented.

Abstract: The ordinary screw designed in traditional method will increase the power consumption and decrease the juice yield in the process of squeeze. Presented the system design of juice extractor firstly, then used the UG software and dimension driving technology to construct the 3d model entity of the screw with variable pitches and diameters, followed by systems three-dimensional model. Finished the static analysis of the screw blade by ANSYS, completing a follow-up study of parameterized modeling.

Abstract: Objective To understand the stresses distribution and process of damage evolution of both matrix and fiber in the defect cartilage under load of compression. The numerical results may provide a reference to both of the design for cartilage alternatives and clinical repair of defect cartilage. Methods The thickness of different layers of cartilage was obtained by a kind of experiment, in which the displacement in different layers zone cartilage under the compression load was obtained by the digital correlation technique. The multi-layer cartilage model with fiber and defect was established by the multi-physics analysis software ANSYS, with the different layers of the cartilage refer to the experimental results. According to the strength condition, the cartilage damage evolution process was simulated by the method of modifying the stiffness of the elements. The influence of the different defect depth to the damage evolution of cartilage was considered in parameter study. Result The simulation results have shown that the stress distribution in matrix was related to the cartilage defect depth. The minimum stress was distributed in the deep areas and below the damage area, stress concentration was located in the both sides of the defect area in the cartilage matrix, and the damaged area developed gradually from surface to deep, the maximum stress located at both sides of defect area. The stress distribution of cartilage fibers related with their location, the compressive stresses are mainly distributed in the middle and deep area, which are greater than those of undamaged. Conclusion In the process of damage evolution, the damaged area gradually developed from the surface to the deep. In the case of defect value of 60%, the maximum equivalent stresses in matrix will be increased in the process of damage evolution; in the case of defect value of 5%, the maximum axial stresses in fibers will be increased in the process of damage evolution.

Abstract: Stress of the cylindrical helical torsion spring is researched with finite element method when torsional degree changes. For spring has great resilience, large deformation effect is considered in the simulations. Analysis on the stiffness shows that the model built is credible, although torsional stiffness is not constant for large torsional angle, the strength is enough whose variation trend is consistent with the spring stiffness with different working torsional angle.

Abstract: In the analysis of car frame that considers the leaf spring, the three degrees of freedom model of leaf spring was proposed. It would be compared with the commonly used equivalent model at present. There is a clear difference between the impacts of the two models on the structure analysis of the frame. The stress and deformation of the frame with the three degrees of freedom model is greater than the commonly used equivalent model, and there is only a smaller value range of lightweight optimization. Through the comparison between the two models, it can be seen that the three degrees of freedom model can transfer force and moment of force in all degrees of freedom, which illustrates the stronger reliability of the three degrees of freedom model of the leaf spring.

Abstract: Starting from observation statistics that oceanography has existed now and based on wave spectrum and the direction spectrum function, the three-dimensional irregular wave mathematical model is built with the method of halving frequency, and according to the wave spectral energy distribution, the number of frequency division and direction segmentation is studied. Last numerical simulation of three dimensional irregular wave is studied by using Matlab, the temporal and spatial wave simulation waveform is obtained. The simulation results show that this method can simulate three dimensional irregular wave accurately and fast.

Abstract: The working principle of the balanced elliptical motion shale shake are presented, Based on the way of parametric design with SolidWorks, The crucial technique for establishing the virtual model is discussed, uses the VBA development tools, realizes the cylindrical cams 3D parameterization design method and the step. The example was given to show the virtual design of the balanced elliptical motion shale shake is presented, the method can effectively improve design efficiency, Provide strong support for the launch of new products, which provides a feasible method for design of the balanced elliptical motion shale shake.

Abstract: The bridge-type displacement amplifier is modeled by the analytical method and finite element method. The analytical relationship between the input displacement and output displacement is established. The analytical model is validated by finite element method. The geometric parameters influence of amplification ratio is studied. The comparison results show that the link length and the link angle influence the amplification ratio dramatically. A small link angle and a large link length is beneficial to the amplification ratio. The finite element method has a more precise simulation results than the analytical method under the circumstance of small link angle and short link length.

Abstract: Rotary tillage is the most common method of modern farming land and the key component which transmits torque and bears soil counterforce and pound. Rotary blade axis（1GBF-12A）was studied in this paper using 3D design software(UG) and finite element analysis software(NX NASTRAN) to establish model analysis and static analysis. The result that the vulnerable area is at the middle of Blade Axis was obtained. The strongest bending stress and position of the Blade Axis is calculated. The research offers theoretical basis for improving future design.