Numerical investigation on effect of the relative motion of stock/switch rails on the load transfer distribution along the switch panel in high-speed railway turnout

Lü

Zhao

et al. 2020

Shock and Vibration

Self Cite

A novel elastic rail clip was obtained through size improvement based on the II-type elastic rail clips to solve the fatigue failure of elastic rail clips. The metro vehicle-track coupling model and the fastener system refinement model were developed to analyze the effects of the material (38Si7 and 60Si2Mn) on the static and dynamic responses of the elastic rail clips and their fatigue performances under rail corrugation. According to the results, the elastic rail clip made of 60Si2Mn did not undergo any plastic deformation and exhibited higher strength than that made of 38Si7. Elastic rail clips made of 38Si7 and 60Si2Mn presented a consistent clamping force, natural frequency, and vibration acceleration. However, they were most sensitive to the wavelength of 50 mm. Both materials influenced the small back bending area of the elastic rail clip only. The elastic rail clip made of 60Si2Mn could meet the fatigue life requirements of 5 million times. As for the elastic rail clip made of 38Si7, the corresponding values of corrugation with the wavelength of 50 mm and 40 mm are to be controlled below 0.09 mm and 0.41 mm, respectively. The performance of the elastic rail clips to resist rail corrugation can be improved significantly through the increase in the geometric dimensions and selection of materials with higher strength.

Section: Calculation Model and Methods Of The Fatigue Life Of Elastic mentioning

confidence: 99%

Analysis on the Effects of Material Parameters on the Fatigue Performance of Novel Anticorrugation Elastic Rail Clips

Lü

Zhao

et al. 2020

Shock and Vibration

Self Cite

“…In this part, we evaluate the performance of simplified models on predicting creep force, which is very important for vehicle dynamics simulation such as vehicle negotiating a curved track [29] and turnout [35,36] as well as modeling track vibration [37,38]. Figure 17 illustrates creep force estimation by different models under lateral shift and mixed creepage and spin.…”

Section: Creep Forcementioning

confidence: 99%

Applying Two Simplified Ellipse‐Based Tangential Models to Wheel‐Rail Contact Using Three Alternative Nonelliptic Adaptation Approaches: A Comparative Study

Mathematical Problems in Engineering

Zhou

et al. 2019

Self Cite

In the modeling of railway vehicle-track dynamics and wheel-rail damage, simplified tangential contact models based on ellipse assumption are usually used due to strict limitation of computational cost. Since most wheel-rail contact cases appear to be nonelliptic shapes, a fast and accurate tangential model for nonelliptic contact case is in demand. In this paper, two ellipse-based simplified tangential models (i.e., FASTSIM and FaStrip) using three alternative nonelliptic adaptation approaches, together with Kalker's NORM algorithm, are applied to wheel-rail rolling contact cases. It aims at finding the best approach for dealing with nonelliptic rolling contact. Compared to previous studies, the nonelliptic normal contact solution in the present work is accurately solved rather than simplification. Therefore, it can avoid tangential modeling evaluation affected by inaccurate normal contact solution. By comparing with Kalker's CONTACT code, it shows both FASTSIM-based and FaStrip-based models can provide accurate global creep force. With regard to local rolling contact solution, only the accuracy of FaStrip-based models is satisfactory. Moreover, Ayasse-Chollet's local ellipse approach appears to be the best choice for nonelliptic adaptation.

“…e site soil layer is divided into 4 layers from top to bottom, and the detailed parameters are shown in Table 4. In this paper, the widely used Rayleigh damping is adopted to reflect dissipation of vibration in soil materials [30,31]. Assuming that the damping matrix of the system is a linear combination of mass matrix and stiffness matrix, the commonly used Rayleigh damping is expressed as…”

Section: Determination Of Calculation Parametersmentioning

confidence: 99%

A Numerical Analysis of Ground Vibration Induced by Typical Rail Corrugation of Underground Subway

Xing

Zhao

et al. 2019

Shock and Vibration

Self Cite

A two-step approach is used to establish a numerical prediction model to study the impact of typical rail corrugation on ground vibration from an underground subway. In the first step, a vehicle-track-tunnel rigid-flexible coupling subsystem is established based on a lumped mass model dynamics and finite element analysis cosimulation method to simulate the generation of vibration. In the second step, a track-tunnel-soil three-dimensional (3D) finite element subsystem is built to simulate the propagation of the vibration. The ground vibration response is obtained by applying the wheel-rail force calculated from the first step. A section of Chengdu Metro Line 3 is studied, and the accuracy of the numerical prediction model is then verified by comparison with in-situ measurement. Based on that, the impact of corrugation on wheel-rail interaction and ground vibration is investigated by taking rail corrugation in typical subway sections and track geometry irregularities as system input excitation. In addition, to further analyze the sensitivity between different wavelength components in the rail corrugation samples and ground vibration, the measured rail corrugation is decomposed into five kinds with different wavelength components by filtering. The results show that the typical rail corrugation has a large impact on ground vibration response, which increases significantly in the range 8–16 Hz and 50–80 Hz, and the impact decreases with the distance from the vibration source. For typical subway rail corrugation with the significant wavelength of 125 mm and the secondary significant wavelength of 63 mm, the ground vibration response is sensitive to two wavelength components at 40–60 mm and 60–100 mm. Rail corrugation with the short wavelength of 60–100 mm significantly affects ground vibration levels.