scholarly journals Investigation of the influence of the railroad track on the stress state of the tunnel lining

2018 ◽  
Vol 239 ◽  
pp. 01020
Author(s):  
Mikhail Pleshko ◽  
Alexei Revyakin ◽  
Natalia Malishevskaya
Keyword(s):  
Stress State ◽  
Numerical Model ◽  
Stress Distribution ◽  
Elastic Layer ◽  
Tunnel Lining ◽  
Railway Track ◽  
Deformation Characteristics ◽  
Railroad Track ◽  
Circular Tunnel ◽  
Moving Vehicles

Tunnel lining takes significant loads from moving vehicles. The consequences of their impact depend on the design of the railway track and the deformation characteristics of its elements. For their study, a numerical model of a circular tunnel has been developed. As a result of the model calculation, the values of the main vertical stresses in the main tunnel structures were obtained. It is established that with increasing loads from the wheel to the rail from 100 to 200 kN, the voltage on average increases by 50%. The stress distribution is affected by the rigidity of the elastic layer. When it increases, the vertical stresses in the sub-rail support decrease nonlinearly, while in traveling concrete they increase nonlinearly.

scholarly journals A lightweight numerical model of railway track to predict mechanical stress state in the rail

2020 ◽  
Vol 4 (2) ◽  
pp. 152-162
Author(s):  
Maryam El Moueddeb ◽  
Francois Louf ◽  
Pierre-Alain Boucard ◽  
Franck Dadié ◽  
Gilles Saussine ◽  
...  
Keyword(s):  
Stress State ◽  
Numerical Model ◽  
Mechanical Stress ◽  
Railway Track

Influence of Pipe Ramming on Stress State of Surrounding Soil and Nearby Tunnel Lining

2016 ◽  
Vol 843 ◽  
pp. 81-86 ◽  
Author(s):  
Alexandr A. Pankratenko ◽  
Nguyen Quang Huy ◽  
Nguyen Duyen Phong ◽  
Andrey S. Samal ◽  
Abdrahman B. Begalinov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Analytical Solution ◽  
Surrounding Rock ◽  
Tunnel Lining ◽  
Circular Tunnel ◽  
Under Construction ◽  
Pipe Ramming ◽  
Plane Problem Of Elasticity ◽  
Surrounding Soil

ANNOTATIONThis article proposes an approach to the prediction of stress state and assessing the strength of a circular tunnel lining and the surrounding rock mass under construction near the production used by the micro-tunneling technology of pipe ramming. The basis of this method is an analytical solution of the corresponding plane problem of elasticity theory.

Stress state analysis of two-way tunnel lining at different stages of soil defrostation

2019 ◽  
Vol 10 ◽  
pp. 160-171
Author(s):  
M.S. Pleshko ◽  
◽  
M.V. Pleshko ◽  
I.V. Voynov ◽  
A.V. Kostyukhov ◽  
...  
Keyword(s):  
Stress State ◽  
Tunnel Lining ◽  
State Analysis

Stress in Bonded Adherends for Single Lap Joints

1996 ◽  
Vol 12 (03) ◽  
pp. 167-171
Author(s):  
G. Bezine ◽  
A. Roy ◽  
A. Vinet
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Numerical Model ◽  
Stress Distribution ◽  
Normal Stress ◽  
Lap Joints ◽  
Axial Loads ◽  
Normal Stress Distribution ◽  
Single Lap Joints ◽  
Element Technique

A finite-element technique is used to predict the shear stress and normal stress distribution in adherends for polycarbonate/polycarbonate single lap joints subjected to axial loads. Numerical and photoelastic results are compared so that a validation of the numerical model is obtained. The influences on stresses of the overlap length and the shape of the adherends are studied.

Natural Frequencies of a Railroad Track

1987 ◽  
Vol 54 (2) ◽  
pp. 299-304 ◽  
Author(s):  
S. P. Patil
Keyword(s):  
Natural Frequency ◽  
Elastic Layer ◽  
Natural Frequencies ◽  
Unit Length ◽  
Added Mass ◽  
Winkler Foundation ◽  
Railroad Track

The natural frequency of an infinite railroad track was first determined by Timoshenko as ωR = √k/m, where k is the constant for the massless Winkler foundation and m is the mass per unit length of the rail. The natural frequencies of the track are determined here by modeling the track as a beam resting on a 3-D inertial elastic layer. It is shown that the mass of the supporting foundation has a significant effect on the natural frequencies of a railroad track. Finally, the concept of “added mass” is introduced in order to determine the natural frequency in a desired mode of vibration, by modeling the track as a beam on the massless Winkler foundation and adding the mass of the foundation to the beam.

scholarly journals Nonlinear subgrade reaction solution for circular tunnel lining design based on mobilized strength of undrained clay

2018 ◽  
Vol 55 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Dong-ming Zhang ◽  
Kok-Kwang Phoon ◽  
Qun-fang Hu ◽  
Hong-wei Huang
Keyword(s):  
Design Method ◽  
Large Strain ◽  
Tunnel Lining ◽  
Subgrade Reaction ◽  
Circular Tunnel ◽  
Nonlinear Solution ◽  
Reaction Solution ◽  
Tunnel Convergence ◽  
Tunnel Lining Design ◽  
Internal Forces

This paper presents a nonlinear solution of a radial subgrade reaction–displacement (pk–ur) curve for circular tunnel lining design in undrained clay. With the concept of soil shear strength nonlinearly mobilized with shear strain, an analytical solution of pk is obtained using the mobilized strength design method. Two typical deformation modes are considered, namely oval and uniform. A total of 197 orthogonally designed cases are used to calibrate the proposed nonlinear solution of pk using the finite element method with the hardening soil model. The calibration results are summarized using a correction factor, η, which is defined as the ratio of pk_FEM to pk_MSD. It is shown that η is correlated to some input parameters. If this correlation is removed by a regression equation, f, the modified solution f(pk_MSD) agrees very well with pk_FEM. Although in reality the mobilized soil strength varies with principal stress direction, it is found that a simple average of plane strain compression and extension results is sufficient to produce the above agreement. The proposed nonlinear pk–ur curve is applied to an actual tunnel lining design example. The predicted tunnel deformations agree very well with the measured data. In contrast, a linear pk model would produce an underestimation of tunnel convergence and internal forces by 2–4 times due to the overestimation of pk at a large strain level.

scholarly journals Numerical analysis of stress-state-dependent damage and failure behavior of ductile steel based on biaxial experiments

2020 ◽  
Author(s):  
Michael Brünig ◽  
Marco Schmidt ◽  
Steffen Gerke
Keyword(s):  
Stress State ◽  
Numerical Analysis ◽  
Numerical Model ◽  
Evolution Equations ◽  
Image Correlation ◽  
Failure Behavior ◽  
Damage And Failure ◽  
State Dependent ◽  
Ductile Steel ◽  
Biaxial Experiments

Abstract The paper deals with a numerical model to investigate the influence of stress state on damage and failure in the ductile steel X5CrNi18-10. The numerical analysis is based on an anisotropic continuum damage model taking into account yield and damage criteria as well as evolution equations for plastic and damage strain rate tensors. Results of numerical simulations of biaxial experiments with the X0- and the H-specimen presented. In the experiments, formation of strain fields are monitored by digital image correlation which can be compared with numerically predicted ones to validate the numerical model. Based on the numerical analysis the strain and stress quantities in selected parts of the specimens are predicted. Analysis of damage strain variables enables prediction of fracture lines observed in the tests. Stress measures are used to explain different stress-state-dependent damage and failure mechanisms on the micro-level visualized on fracture surfaces by scanning electron microscopy.

scholarly journals The experimental validation of a numerical model for the receptance prediction

2019 ◽  
Vol 286 ◽  
pp. 01007
Author(s):  
A. Zougari ◽  
J. MartÍnez
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Experimental Validation ◽  
Parametric Design ◽  
Experimental Methodology ◽  
Railway Track ◽  
Experimental Result ◽  
Ballasted Track ◽  
Ansys Parametric Design Language

The traditional ballasted track with wooden sleepers covers today most railway lines constructions, including the tracks of tram and metro or the industrial railway branching. In this work, we present an experimental methodology to validate a numerical model based on finite element method, the model was previously well defined using the ANSYS Parametric Design Language (APDL) and adapted to represent a classical ballasted track. The obtained result of the analysis is expressed as a frequency response of the track and it is compared to the experimental result from measurements made on the metropolitan classical railway track of Barcelona.

Effect of the frictional coefficient and pre-tension on stress distribution of fabric during the weaving process

2017 ◽  
Vol 88 (8) ◽  
pp. 904-912
Author(s):  
Zhiping Ying ◽  
Zhenyu Wu ◽  
Xudong Hu ◽  
Xiangqing Zhou
Keyword(s):  
Numerical Model ◽  
Stress Distribution ◽  
Mechanical Performance ◽  
Frictional Coefficient ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Tension Stress ◽  
Initial Shape ◽  
Warp Tension ◽  
Fluctuation Range

The non-uniform stress distribution of woven fabric has a significant influence not only on its mechanical performance in service, but also on its weaving efficiency in the fabrication process. For investigating the stress distribution in woven fabric, a numerical model at the yarn scale was established to simulate the interlacing process between the weft and warp yarns using an explicit finite element solver. The yarns were assumed to be a homogeneous continuum and the transversal isotropic constitutive equation was used. A modified lenticular initial shape was used as the cross-section of the yarn and trajectories of warp and weft yarns were set to be straight. The classical Amonton–Coulomb law was used for the tangential behavior between the weft and warp yarns. The simulation results reveal that the interaction between weft and warp yarns consists of three phases in terms of contact, adhesion and sliding. The sectional stress distribution in the weft yarn determined by multi-points contact between a single weft yarn and a group of warp yarns was also analyzed. The tension stress of the weft yarn was larger in the middle part than that in both sides. Based on the numerical model, the effects of two key parameters, namely the frictional coefficient and weft pre-tension, on the stress distribution were discussed in detail. The weft crimp angle and warp tension distribution uniformity decreased as the frictional coefficient decreased, whereas the warp tension fluctuation range did not obviously decrease. However, an improved method by exerting pre-tension in two ends of weft yarn was proposed and the warp tension fluctuation range was significantly decreased. The distribution trend of warp tension obtained from the numerical simulation showed an acceptable tendency with experiment measurements.

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