Papers by Keyword: Dynamic Characteristics

Abstract: This paper presents relationships between some vital parameters and the natural frequency of the ball screw feed drive system. A finite element model (FEM) of a machine tool feed drive system is established with joint parameters added in based on the SAMCEF software. Using the finite element model, the influences of the material properties of the worktable, the diameter of the ball screw and joint parameters on the natural frequency of axial vibration are derived. These results provide a reliable basis for the optimization design of the ball screw feed drive system.

Abstract: The present study deals with the application of the Magneto-Rheological (MR) fluid assisted semi-active damper as a replacement to the conventional suspension system in Maruti 800 car (source vehicle). MR fluid damper is designed, fabricated and automated with a microcontroller. This experimentation is carried out with real time instrumentation on the selected road profile as a vehicle dynamic approach. Results obtained from the travel imply that MR fluid suspension suppresses the vibrations more effectively than the existing passive damper system. The MR fluid dampens the acceleration and displacement of the piston to a greater extent thereby controlling the ride comfort.

Abstract: The analysis of torque-speed characteristics of induction motors has been carried out in order to choose the base design for variable speed traction electric drives of underground mine electric locomotives. For constant dimensions of active part of series-produced electric motors the influence of the diverse conductivity’s materials for manufacturing the squirrel-cage rotor on speed-torque and speed-current characteristics. The designs are compared according to speed-up dynamics, power indexes and key design features of the studied electric motors.

Abstract: In order to improve the vibration isolation performance of engine mount, a new type of magneto-rheological semi-active mount with multiple inertia tracks is designed based on the existing magneto-rheological semi-active mount . The mechanical model is established according to the mount. The expression of the dynamic stiffness and damping lag angle is deduced, then the dynamic characteristics is simulated in the simulation software. At the same time, verify this model correct by the experiments.

Abstract: In this paper, bi-directional fluid-solid coupling numerical analysis method was introduced into the structural design of hydrodynamic coupling, this method was adopted to simulate the impeller strength and analyze the dynamic characteristics of the turbine blades, as well as the influences of turbine blades deformation the inside flow filed of hydrodynamic coupling was discussed. The work provides a theoretical basis for the design of the hydrodynamic coupling with the great power and high speed.

Abstract: The penetration cracks in sluice concrete structure have more disadvantage influence on the structure integrity. On the condition of earthquake, it may cause structure collapse. For a typical sluice structure found penetration crack in construction, the finite element model is created and the structure dynamic computation is applied with response spectrum method. The calculation results show if the reinforced steel bar cross the crack is not rusted and destroyed, the tension stress in the sluice and the general safety factor against sliding will meet the corresponding standard. As for the existing cracks, seepage prevention is suggested to avoid steel bar against rust.

Abstract: As the key part of EMU axle measurement system , the gantry, which carrying on high-precision sensors,its vibration frequency generated by the external excitation has an important influence on measurement accuracy, so the analysis about gantry’s natural frequency and model shapes. This paper describes the finite element modal analysis theory briefly , establishes analysis model structure of gantry by ABAQUS, obtains each vibration mode shapes and its corresponding natural frequency through the analysis for model. Finally, we figure out the frequency range that the external excitation should avoid. Meanwhile, a method that decreases external influence by using an independent foundation and air mounts is proposed. This work lays a solid foundation of large-size and high-precision EMU axle measurement.

Abstract: The actual tailings dam as an object, analyzes on tailings dam of the different slope ratio, which under earthquake dynamic response characteristics and stability. The results show that, with the increase of the tailings dam slope than the maximum relative displacement becomes larger, the absolute acceleration amplification factor decreases. In the same slope ratio, the tailings dam displacement and maximum acceleration dam piled high with increased accumulation becomes larger. Sand soil absorption of seismic waves of high frequency, low frequency component.

Abstract: Shallow inland water resources has a large potential for development. To Jiyang shallow groundwater for example, through the regular ion-test analysis, Piper diagram and hydrogeochemical characteristics, the results show that: (1) The type of chemistry of shallow groundwater inland were Cl·SO₄-Mg·Na·Ca; (2) The salt water area is relatively fixed, there is no expansion or decreasing trend; (3) The level flow of shallow groundwater is slow and water rock interaction is strong, that is not conducive to the shallow groundwater quality improvement, changing the runoff conditions of shallow groundwater is essential way for shallow groundwater resources exploitation.