Applied Mechanics and Materials Vols. 541-542

Abstract: In generally cylindrical container, by the method of separation of variables solve the Laplace equation and linearized boundary conditions and obtain amplitude equation of double-frequency excitation fluid interface waves considering surface tension effects. We use double-layer single-frequency viscous fluid damping coefficient to modify the amplitude equation, and then analyze the instability of the new amplitude equation using Floquet theory. By numerical calculation, the instability region determined by different depths, excitation frequency, excitation amplitude, relatively amplitude factor, the phase difference and the surface tension is given. Moreover, the double-frequency excitation spectrum of double critical phenomena is also discussed.

Abstract: In view of analyzing the whole side crashworthiness, based on C-NCAP side impact regulations, this study has analyzed the structural characteristics influencing the side impact of car, and proposed the corresponding structural optimization case. According to FEM, the body optimization case has been simulated and contrasted with the real results. As a result, a good side crashworthiness of the car has been obtained, which helps reduce the cost and the quality of the car. Besides, the study has also done simulation work of the rigidity and modal of the body-in-white and compared it with the real results, which has further tested the correctness of optimization model and helped achieve effective approaches to the design of the car side crashworthiness.

Abstract: The parameter modeling for the front double-wishbone independent suspension of a vehicle is set up in the development environment of ADAMS, and then, the kinematics simulation analysis for original design parameters are processed. The contribution of design parameters to the sensitivity of the double-wishbone independent suspension is analyzed and the influence of design parameters on the performance of the suspension such as the wheel alignment parameters is investigated. The optimal design for the suspension is carried on by using the experiment design method, which not only realizes the requirement for good wheel alignment parameters, but also improves the sideways displacement of wheel obviously.

Abstract: The casting process CAD system developed based on the existing three-dimensional CAD software has many inadequacies. This paper innovatively puts forward the steel castings three-dimensional casting process CAD system based on neutral STEP file. In this study, by taking advantage of universal CAD data-exchange standard STEP format for data exchange, a practical three-dimensional CAD system was developed based on Open CASCADE Geometry Kernel. The system has the function of practical casting process modeling, including design and modeling of gating system and riser design and so forth. The system exceeded the deficiencies of the existing casting process CAD system. It resolves the foundry Enterprises dependence and limitations on the type and version of commercial 3D CAD software, enabling to realizethe integration of CAD and CAE on casting process.

Abstract: Lifting machinery usually fail or become scrapped after a certain period of use for a variety of reasons. Thus, they often need remanufacturing technology. The purpose of this paper is to research and analyze how to apply remanufacturing technology to lifting machinery. In this paper, the background of remanufacturing technology is firstly discussed. Then illuminate the specific processes of remanufacturing technology including the cleaning measures of those components after dismantled, the non-destructive examination (NDE), and assessment software using to test the perfectness of the produces remanufactured. Finally, the benefits of the widespread use of remanufactured lifting machinery which can make the best use of various resources to achieve energy saving, material saving and environment protection goals are discussed in order to draw key conclusions.

Abstract: Based on uniform design, finite element simulation of dieless tube hydroforming and double-screening stepwise regression method, a many-to-many polynomial regression equation set was established, whose independent variables are time t₁ at which axial compression displacement from 0 reaches 25mm and time t₂ at which internal pressure from 0 achieves 65MPa in 60 seconds, while dependent variables are hoop plastic strain s₁₁ and radial plastic strain s₂₂ in the midmost position of hydroformed tube. Analysis of partial correlation coefficient indicates that the effect of t₂ on s₁₁ is a little stronger than t₁ and there is no interaction between t₁ and t₂ on s₁₁, while s₂₂ is influenced by t₂² and t₁t₂². The many-to-many regression model not only quantificationally describes the action of loading factors on plastic strains but also reflects the inherent relevance between plastic strains, which is more useful than several one-to-many regression models to solve problems such as loading characteristic analysis, loading parameters design and optimization, etc.

Abstract: Ultrasonic vibration deep hole drilling is a kind of new technology for combining ultrasonic vibration with deep hole drilling. This paper mainly describes the transformation of lathe, vertical milling machine and vertical machining center by bits vibration direction or adding some auxiliary institutions, then make it have the ability of drilling deep hole. With these transformation, machine tools have some advantages, such as the efficiency and precision are improved, machining quality is stable, chip removal is easy, the cost is low. Besides, it also provides a good way for making full use of existing equipments.

Abstract: In order to collect the fault signal of slewing bearing, design and built up the slewing bearing test rig and the signal test system. Because slewing bearing fault signal is weak, the signal containing fault characteristics was resolved and reconstructed with the wavelet theory. With the application of the Hilbert transform in demodulation and detailed spectrum analysis, the fault characteristic frequency was extracted, and the slewing bearing fault was judged. All above work shows that Wavelet analysis combined with the Hilbert analysis is effective to the diagnosis of rotary bearing local fault.

Abstract: In view of the problems serious leakage of lubricating oil in the current slide bearing of a ship motor shaft sealing.This paper analyzed the reasons of bearing oil through the work principle of sliding bearing and the sealing structure. And put forward to solve leakage measures, provide a certain reference value for the seal structure design of sliding bearings and other rotation machine .

Abstract: Wire race ball bearing with large radial size and small axial size, saves space extremely, and is widely used in rotary devices of large machineries. This paper establishes a mathematical model of optimization design of rectangular cross-sectional wire race ball bearing,and considers minimum friction torque as objective function, and analyses constraints of contact intensity and design specifications of wire race ball bearing, and forges an optical design method that determines the number of balls, the diameter of ball, the contact angle and the diameter of ball center circle as optimal design parameters, to attain the purpose of extending bearings life. Comparing results of Optimization with original sample, the friction torque of ball that bears maximum load reduces by 10.20%. This method provides a reference for conducting further scientific researches on wear of wire race ball bearing.