Papers by Keyword: Vibration Mode

Abstract: With the high-speed and high-precision development of CNC machine tool, the vibration problem of ball screws linear guide feed unit has become more and more prominent. The dynamic characteristics was analyzed for ball screws linear guide feed unit, the 3D finite element model was built, the finite element modal analysis was discussed, the natural frequency and vibration modes were obtained, which were compared with the test results. The vibration weaknesses of ball screws linear guide feed unit were found out. The results show that the vibration weaknesses of ball screws linear guide feed unit occur mainly in the ball screws and its connection part with the worktable, its natural frequency are affected by its supporting pattern, and more close to the test results compared with those of ball screw feed unit without considering linear guide, which provide theoretical basis for the structure optimization of ball screws linear guide feed unit.

Abstract: X-PLY Corrugated Paperboard is a new type of cushioning packaging materials, which has a light weight, strength and stiffness and other advantages, usually be made into cushioning pads (pieces) and used in the field of logistics and transport packaging to protecting internal product from shock and vibration. In the actual logistics process,external vibration excitation is often caused package resonance and lead to final damage of the package, so understanding the package natural frequencies and mode shapes, which can avoid package resonance factors causing unnecessary losses. By using of Lanczos modal analysis method in ANAYS simulation software, we obtains the first-fourth natural frequency and vibration mode of X-PLY (A) corrugated paperboard cushion pads under three different static stress. By compared simulation results with the previous experimental results, it can be referenced for the promotion and application of X-PLY corrugated board in the field of Cushioning packaging.

Abstract: The constant matrix and piezoelectric equations of quartz crystal material are introduced in this paper. Vibration characteristics of quartz crystal is analyzed under several important vibration mode and coupled modes are explained. At last, some measures to suppress the QCM vibration coupling is presented.

Abstract: Due to the increase of environment requirements, Fiber glass Reinforced Plastic (FRP) chimney liners are frequently used in coal-fired units. Wind and earthquake loads play an important role in the design of FRP chimney liners. Most of the engineering staff are still accustomed to accept single model, although, conjunctive model can reflect the effect of concrete cylinder on FRP liners and obtain more accurate internal forces of the liners under earthquake and wind loads. In this paper, a novel modified single model method is put forward to obtain accurate results.

Abstract: A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

Abstract: A bump of irregular frame structure as an example, the use of ANSYS software, the structure dynamic characteristics analysis, given the cycle ratio and modal participation mass percentage, as the bump of irregular frame structure design reference.

Abstract: The rigid-flexible coupling model of wind turbine was established in ADAMS to study the vibration characteristics, which was based on the working principle of megawatt wind turbine. The natural frequencies and vibration modes of the tower have been obtained by dynamic simulation analysis and vibration analysis of the wind turbine. The comparison of the first-order bending natural frequency by raley analysis algorithm and the first-order bending natural frequency by the software, which has validated the correctness of rigid-flexible coupling model of wind turbine, the analysis of vibration characteristic has verified the rationality of the structure of the wind turbine.

Abstract: The roll-on process of the ship loader is studied with the finite element method in this paper. The principle and the scheme of the parametric modeling for the ship loader have been discussed. The vibration frequency and the vibration mode of the ship loader in the roll-on process have been researched, and the weaknesses in the structure of the ship loader have been founded. Based on the above discussion, the reinforcement scheme of the ship loader has been put forward, and the vibration mode and frequency of the strengthened ship loader in the roll-on process have been analyzed. With the comparison of the original one, the anti-vibration performance of the strengthened ship loader has been improved, the reinforcement scheme has been proved to be a worthy one in the roll-on process.

Abstract: The track measuring beam is installed in the bogie frame to measure the geometry parameters of the rail. In this paper, the dynamic model of the inspection car was established in order to compare the dynamic properties of the vehicle with and without track measuring beam installation. The motion stability, ride quality, vibration acceleration and curve negotiation performance of the vehicle after the track measuring beam installed were investigated. The results show that after the track measuring beam installation the critical velocity of the inspection car decreases, but the running at speed of 120km/h can be guaranteed. The track measuring beam has no influence on the ride quality and curve negotiation performance and the effect of it on vibration mode is little.

Abstract: A purely torsional dynamic model of closed-form planetary gear set is developed to investigate its natural frequency and free vibration modes. The closed-form planetary gear set considered consists of two-stage planetary gear connected by high-speed carrier and ring gear. Three identical planet gears are equally spaced in each stage. Based on the precondition, the natural modes are classified into three types of vibration modes: overall modes，high-speed planet mode and low-speed planet mode