Applied Mechanics and Materials Vol. 684

Abstract: A fast tool servo system is developed for the fabrication of micro-structured surface on a diamond turning machine. The fast tool servo (FTS) system in this investigation employs a piezoelectric actuator to actuate the diamond tool and a capacitance probe as the feed back sensor. To compensate the inherent nonlinear hysteresis behavior of the piezoelectric actuator, Proportional Integral (PI) closed loop control with a feed-forward predictor is implemented. The result of closed loop experiment in FTS demonstrates that the tracking error has been reduced to a level of less than 150nm. Actual experiment of fabricating the sinusoidal grid surface was performed on an ultra-precision diamond turning machine designed by Center of Precision Engineering of HIT. The fabrication of a sinusoidal grid surface has indicated the effectiveness of the fabrication system.

Abstract: Using the method of finite time thermodynamics, and quoting the ecology objective function to optimize the performance of the dual sound source driven thermoacoustic refrigerator regenerator. And Use the characteristic time to characterize the transducer effect in the thermoacoustic system in order to seek the optimal relationship between the characteristic time and ecology objective function. Numerical calculation results show that the impact of the relationship between ecological function and the characteristic time is parabolic curve, so there is an optimal characteristic time to maximize ecological objective function values.

Abstract: The virtually assemble model of the L-10/7 piston type air compressor with double actions was established under SolidWorks software. The kinematics and dynamics simulation of compressor’s crank-link mechanism were done by SolidWorks Motion, and the main results of simulation were given out, the results coincide with the date of design calculate. It can be used as the foundation for stress calculation and optimization design of the air compressor.

Abstract: Design a kind of reducer, the first stage transmission is a cylindrical cam, the secondary stage transmission is a gear transmission. Multistage transmission of the reducer has carried on the design calculation and checking. On the basis of the lateral cylindrical cam lateral transmission mathematical model, conducted the spiral curve analysis and calculation with numerical analysis software MATLAB. Import the spiral curve data into SOLIDWORKS to complete the 3D modeling of cylindrical cam. According to the structural design of cylindrical cam, complete reducer machine design and virtual assembly of gearless reducer. The stress analysis was carried out on the cam disk with the ANSYS Mechanical Analysis Module of SOLIDWORKS, designed to meet the working conditions. Conducted physical development based on CAD and CAE. The result showed that the design was fast and effective, significantly shorten the production cycle.

Abstract: The front axle is an important part of a car, directly affects the dynamic characteristics of car. Based on UG NX6.0 for automobile front axle parts 3D modeling, finite element analysis software ANSYS modal analysis was carried out on the front axle, and extract their first four order natural frequency and vibration mode shapes, the automobile front axle structure stress analysis and stress distribution nephogram of get parts. Analysis of the impact load condition and emergency braking conditions modal analysis, and further to fatigue analysis of the front axle bridge shell, for provide valuable reference data for the reasonable design of parts. For the kinetics of further research and improvement of front axle provides the theoretical basis, but also provides reference to the actual test.

Abstract: This paper focus on the detailed influence of forward-facing cavity on the opposing jet. The flow field of a hemisphere nose-tip with the combined configuration was simulated numerically and the surface heat flux distribution was obtained. The numerical results show that a suitable cavity is helpful for the opposing jet. With the same total pressure, the single opposing jet even can’t form a stable flow field and there is no cooling effect.

Abstract: The shaft as an important parts of automobile transmission system, in the process of the car have the effect of rotational speed and torque. Due to the structural characteristics of its low frequency, small stiffness, universal joint, such as the existence of the additional moment drive shaft inevitably exist when high speed vibration phenomenon. So the shaft vibration problems to deal with the vehicle ride comfort, comfort and dynamic performance has important significance. On the basis of the finite element software ANSYS, the physical design of drive shaft. Analyzes the mapping grid finite element model of transmission shaft, facilitate accurate transmission shaft strength calculation. Based on the inherent frequency and vibration model of finite element method to calculate transmission shaft, using experimental modal technology for modal analysis of the shaft, the test results verify the reliability of the finite element model. On this basis, the drive shaft assembly constraint modal finite element analysis, can be used as the basis of further research.

Abstract: The paper analyzed the temperature field and the thermal stress field of a diesel engine piston with finite element analysis software ANASYS, then used the thermal mechanism indirect coupled method, researched the coupled stress field of piston. The result indicated that the point of the highest temperature located on the middle of firebox which under the dangerous temperature of the material; under thermal stress effect, the max displacement of the piston did not exceed the clearance between piston and cylinder liner, but the non-roundness at the third ring reached 0.08mm, which had some influence on the pressurize and lubricate of piston; under thermal mechanism coupled effect, the point of max stress located on the interface of the seat of the pin and the pin hole, so as the top on the pin hole and inner on the seat of pin, so it was recommended to set rib between cervix and the seat of pin of piston to enhance the practical carrying capacity of the seat of the pin.

Abstract: The achievement of space orbit service space autonomous docking technology. At present, many kinds of autonomous docking mechanism are appeared according to different service object. In order to widen the application range from lives of docking mechanism, design a space rod - cone docking mechanism in this paper. The mechanism can be in the context of a larger space, achieve self-occupied docking. And based on the ADAMS-View to complete the mechanism dynamics virtual prototype. According to the space orbit autonomous docking technology, set up virtual prototype mainly docking detection parameters, Analysis of dynamic characteristics in the whole of the docking process and complete the mechanism.

Abstract: Based on the study of planetary differential roller screw, a planetary differential micro-displacement mechanism is designed for tool compensation. Axial stiffness is an important factor of over-all properties of planetary roller screw. The structure of planetary differential roller screw is similar to planetary roller screw. The axial stiffness was analyzed with Hertz contact theory and confirmed with the ANSYS. Finally, the theoretical values and simulation values were compared to verify the simplified model, and the error was analyzed. The results show that the relative error between simulation values and theoretical values are less than 5%. Therefore, the simplified model of the finite element is reasonable.