Advanced Materials Research Vols. 605-607

Abstract: Milling head box is an important supporting part of spiral drill collar machine. Its dynamic performance has a big effect to the machine tool working accuracy. The three-dimensional (3D) model of milling head box was built in this paper. With finite element analysis software, the dynamic performance of the box was analyzed. The first six natural frequencies, relevant vibrations and mode shapes of the box were obtained. The results indicate that the milling head box structure is reasonable. No resonance will be induced during the machining process. It also provides thoughts and reference for further dynamic performance researches with practical significance.

Abstract: Analyzing some main errors of NC spiral bevel gear honing machine-tool, the elements of geometric error, thermal error and force error etc., which are constructed 39 error sources of the machine by stack method. Based on multi-body system theory, using homogeneous transfer matrix(HTM) method to present six feature matrixes that includes ideal-static matrix, ideal-kinematic matrix, ideal-static translation error matrix, ideal-static rotary error matrix, non-ideal rotary motion error matrix and non-ideal translation motion error matrix, which are built between of adjacent body. Finally, the synthetic volumetric error model of six-axis honing machine-tool is established.

Abstract: The isolation design of the ship must be considered based on flexibility, usually using vibration power flow analysis theory. The proposed vibration power flow based on finite element method aims the optimization to minimize the vibration power flow. The rubber elastic element structural optimization method has been study as follows.

Abstract: This paper simplified the wheel-Lower Control Arm-frame system into a two DOFs vibration system and analyzed its transmission characteristics by modeling the LCA rubber bushing in Kelvin-Voigt model, Zener model and Berg model, respectively. The results show that the system with Berg model shows obvious amplitude-dependent characteristics. Its magnitude and frequency at the peak of the transmission curve change as the excitation amplitude changes. The system with Kelvin-Voigt model or Zener model shows none amplitude-dependent characteristics. It’s more effective and more exact to model the LCA rubber bushing in Berg model than the others.

Abstract: Centering on the chuck shaft vibration problems in high speed operation of the high-speed winder, experimental modal analysis was used to identify the modal frequency and vibration modes of the chuck shaft different cross-section in the constraint, found out the sensitive point of the response signal ,and the excitation point was found by Relationship between the modal frequency and the input excitation frequency, the results show determined dominant frequency components in the response signal can provide a reliable basis for determining the vibration characteristics of the chuck shaft, analysis of distinguishing the output response signal and selecting response signal point.

Abstract: Modal analysis is a main method of researching the dynamic performance of the system structure. The deformation of Needle-punching machine frames in the work will affect the whole machine performance, which would seriously influence acupuncture frequency, reduce production efficiency. At the meantime, machine life will be shortened. Here, Needle-punching machine modal experiment has been done, the static natural frequencies and modal deformation animation of frame also has been calculated, that provides a reliable guide and basis for the actual work of deformation for needle-punching machine.

Abstract: According to relevant dynamics theory, finite element model of a three-ring gear reducer was established considering the deformation of gear’s teeth. The finite element model was analyzed under different phase angle, the real contact teeth and the stress in contact teeth was got from the analysis, which could steering the design of the three-ring gear reducer.

Abstract: Tower crane is a kind of construction machinery which be widely used in building, bridge, electric power construction. The factor for hoisting a grounded load is one of main factors for dynamic analysis and structure design of tower crane. Different structural forms of tower crane have different effects on the factor for hoisting a grounded load. The finite element models of QTZ125 tower crane with different top-structure form are build and the first six order inherent frequencies and vibration modes are analyzed. Then the factors for hoisting a grounded load at lifting velocity of 0.2~0.5m/s under lifting operation condition are calculated. Based on the results, the influence of the different top-structure of the tower crane to the dynamic characteristic and the factor for hoisting a grounded load is prominent, and the factor for hoisting a grounded load of support-rod type tower crane is less than the tower-cap type tower crane.

Abstract: With the large-scale speed-up of the railway, the dynamic track stabilizer will play an important role on the track overhauling and railroading of new line in our country. Bogie is one of the major critical components of the dynamic track stabilizer; its vibrating characteristic will affect the vibrating characteristic of the dynamic track stabilizer directly. The method of numerical simulate was used, based on ADAMS simulation, the horizontal exciting forces of the vibration exciter under working conditions were gained. Then the exciting forces were loaded on the bogie, and the dynamic characteristics of the dynamic track stabilizer bogie under the working conditions were obtained on the bases of the ANSYS/LS-DYNA. The analysis results show that the lateral and nod vibrating characteristics of the bogie under working conditions were strong. The analysis results of this paper will provide foundation for the research on the dynamic characteristics and working security of the dynamic track stabilizer.

Abstract: The dynamic problem of a free-free beam with lumped masses distributed along the beam is researched. Effects of magnitude and position of lumped masses on bending mode and natural frequency of a free-free beam is studied. Method of lumped masses proposed in this paper is used to determine dynamic bending curves and natural frequencies. Least square method is used to give function fitting of the bending curves. The dynamic equations of a free-free beam are established by Lagrange method. Numerical simulation for dynamic response of the beam is carried out by MATLAB. The simulation results show that an impulsive load applied on the center of mass of the beam will result in small bending stress. However, a given larger impulsive load acting on one end or two ends of the beam will cause larger bending stress and plastic deformation at a cross-section and result in final failure.