Super handyscan 4000 manual11/9/2022 ![]() Furthermore, a mathematical model is developed to illustrate the forming process of rail corrugation, and the results indicate that the corrugation generated on curved track can be attributed to the periodical fluctuation of frictional power due to torsional vibration. In this research, a finite element model including the nonlinear friction-creepage characteristics is developed to analyse the unstable vibration of a wheelset negotiating a curved track, and the results show that the friction induced torsional vibration between inner wheel and rail is most likely to be generated, which can verify the assumption. This assumption, however, has not been investigated in details yet. The phenomenon that corrugations are generated on curved tracks can be explained with the assumption that corrugation is generated by the torsional vibration of wheelset. Recently, field measurements show that corrugations are generated on curved tracks and that its wavelength varies with fasteners. Finally, the identified wavelength-frequency relationships and the measured rail irregularity can empirically demonstrate that the generated corrugation on the rail is produced by wave interference on the two axles in the bogie. As a result, the wavelength (wavenumber)-, group velocity-, and distance damping (attenuation) frequency relationship of the wave propagation is clarified in addition to the rail frequencies and mode shapes up to approximately 1500 Hz, including the pinned-pinned mode. ![]() Additionally, the proposed method is applied to an actual rail with a direct fastening track system on a bridge that has corrugation with a wavelength of approximately 0.04 m. In this study, a novel and field-applicable method for identifying rail vibration modes and wave propagation characteristics is developed by multipoint hammering and the reciprocity theorem instead of multipoint measuring. However, the ability to identify actual railways has been limited because of the huge number of sensors required for field tests. Vertical bending vibration modes and rail wave propagation, including the damping characteristics, are the factors that cause rail corrugation. (4) The change of fastening stiffness and damping can control rail mode frequencies and their vibration amplitude, and influence the wave propagation velocities and attenuation along the rail. (3) Compared to the vertical and lateral directions, the fastening system constrains the longitudinal rail vibrations less strongly. (2) Vertical wave attenuation of rail-fastening is relatively small between 18 Hz, and lateral wave attenuation presents a dominant peak at about 3800 Hz. #Super handyscan 4000 manual free#The results indicate that (1) under fastening constraint, ODS measurement identifies vertical bending modes, longitudinal compression modes, and lateral bending modes of the rail with shifted frequencies and significantly reduced vibration amplitude compared to that of free rail. ![]() In Step 3, insights into the control of rail vibrations are gained by sensitivity analysis of fastening parameters using the validated 3D FE model from Step 2. In Step 2, a 3D FE model capable of reproducing the dynamic behaviors of rail-fastening up to 5000 Hz is developed to analyze rail vibrations and validated using measurements from Step 1. In Step 1, operating deflection shape (ODS) and synchronized multiple-acceleration wavelet (SMAW) measurements are applied to identify rail vibration modes and measure wave propagation characteristics under fastening constraint. Three steps are considered: 1) experimental investigation of rail vibrations under fastening constraint 2) validation and analysis of 3D finite element (FE) modeling of rail-fastening systems 3) rail vibration control by fastening parameters. A methodology is proposed, including experimental investigation and numerical simulations of rail vibrations. This paper investigates three-dimensional (3D) rail vibrations under fastening constraint up to 5000 Hz and provides insights into rail vibration control by fastening parameters. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |