Failure analysis and fatigue life prediction of high-speed rail clips based on DIC technique

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110662
Author(s):  
Yan Liu ◽  
Xiujie Jiang ◽  
Qiutong Li ◽  
Huan Liu
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Fatigue Failure ◽  
High Speed ◽  
Experimental Tests ◽  
Image Correlation ◽  
Fe Model ◽  
Rail Transportation ◽  
High Speed Rail ◽  
Dic Technique

With the development of rail transportation, the fatigue failure of rail clips has become an issue, which affects the operational safety of trains. In this study, reasons for the fatigue failure of rail clips were investigated to improve their service life. A digital image correlation (DIC) technique was conducted to obtain strain fields, vibration modes, and natural frequencies of a rail clip. The strain and displacement of a rail clip under dynamic cyclic loading were also obtained. A fastener system refinement model was developed to analyze the static, dynamic, and modal responses of the clip. The experimental tests and modal simulation results were mutually verified. The fatigue life was analyzed based on the verified FE model. The results revealed that the maximum strain and minimum fatigue life occur at the heel of the clip, in good agreement with the actual fracture position. As the amplitude and frequency of dynamic cyclic load increased, the fatigue life of the clip decreased sharply. Moreover, the normal wheel–rail force accompanied by high-frequency rail corrugations accelerated crack initiation and reduced the fatigue life. The findings of this study provide guidance for improving the service life of rail clips.

Calculation Error Analysis on the Strain Fatigue Life Predication Formula of Manson-Coffinn and Damage Stain Model

2011 ◽  
Vol 197-198 ◽  
pp. 1599-1603
Author(s):  
Zhen Wei Wang ◽  
Ping An Du ◽  
Ya Ting Yu
Keyword(s):  
Fatigue Life ◽  
Error Analysis ◽  
Fatigue Failure ◽  
High Speed ◽  
Production Cost ◽  
Calculation Error ◽  
Mechanical Components ◽  
Strain Model ◽  
Engine Crankshaft

Mechanical components are subjected heavy alternate load in industries, such as engine crankshaft, wheel axle, etc. The fatigue failure happens after a long work loading, which affects the production cost, safe and time. So the fatigue life predication is fundamental for the mechanical components design. Especially, it is very important for heavy, high-speed machinery. In this paper, both main fatigue life predication formulas are introduced briefly, including Manson-Coffinn formula and Damage strain model. Then, shortages of above life predication formulas are pointed out, and coefficients are explained in detail. Further calculation error analysis is conducted on the basis of experiments on 16 materials. Results show that above life predication formulas lack calculation accuracy. Finally, it is pointed out that coefficients of fatigue life predication formulas are dependent of material performance. So it is unreliable that coefficients are constants for Manson-Coffin and Damage strain model.

scholarly journals Fatigue life investigation of UIC 54 rail profile for high speed rail

2017 ◽  
Vol 908 ◽  
pp. 012026 ◽  
Author(s):  
P Gurubaran ◽  
M Afendi ◽  
M A Nur Fareisha ◽  
M S Abdul Majid ◽  
I Haftirman ◽  
...  
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
High Speed Rail

Emerging Challenges and Opportunities for U.S. High-Speed Rail Development

2016 ◽  
pp. 81-123
Author(s):  
Francis P. Banko ◽  
Jackson H. Xue
Keyword(s):  
Best Practices ◽  
High Speed ◽  
Task Force ◽  
Lessons Learned ◽  
Rail Transportation ◽  
High Speed Rail ◽  
International Experiences ◽  
Challenges And Opportunities ◽  
Tier I

As we witness the advancement of U.S. high-speed rail initiatives, the country can look towards its European and Asian counterparts for best practices and lessons learned from their decades of high-speed rail design and operations. These experiences gained may be applicable towards projects such as the Texas Central Railway and the California High-Speed Rail Project. This chapter will address the events of 2009 that have brought domestic high-speed rail to the forefront of U.S. rail transportation. This includes the new FRA Tier I and proposed Tier III criteria, challenges associated with each FRA tier of operation, overseas interoperability efforts, snapshots of international experiences (from policy and technological perspectives), the holistic system-based approach to safety, ongoing efforts of the FRA Engineering Task Force, and additional challenges and opportunities moving forward.

scholarly journals Fatigue Life Characteristics of Segmental Lining Structure for the Shallow Buried Metro Tunnel under the Dynamic Load of a High-Speed Railway

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Wangping Qian ◽  
Taiyue Qi ◽  
Qing Zhao ◽  
Bingrong Pu ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Failure ◽  
Dynamic Load ◽  
High Speed ◽  
Dynamic Loads ◽  
High Speed Railway ◽  
Segmental Lining ◽  
Lining Structure ◽  
Metro Tunnel

Shallow buried shield metro tunnels constructed underneath subgrade project of high-speed railways are becoming increasingly common in China, but the lower metro tunnel bears the fatigue effect of dynamic load induced by the upper high-speed railway, so the long-term durability of segmental lining is a nonnegligible problem. The segmental lining structure of metro tunnel is in a state of static-dynamic loads for a long time, especially when a high-speed railway passes above the metro line, and the long-term durability of segmental lining needs further research. Based on theoretical analysis, the effect of different forms of loads on the fatigue life was analyzed, the change law of the static-dynamic loads on segmental lining was summarized, and the method was put forward to evaluate the fatigue life characteristics of segmental lining. The research results reveal that the additional dynamic load is the fundamental reason for the fatigue failure of the structure, and the existence of static load can cause and accelerate the occurrence of structural fatigue failure simultaneously. The results indicate that the fatigue life decreases gradually with the increase of static-dynamic load. Based on coupling analysis of static-dynamic loads of segmental lining, the fatigue life increases first and then decreases with the increase of buried depth of metro tunnel, and it remains unchanged when the depth exceeds a certain value. According to the actual metro tunnel engineering, by using ABAQUS software, a three-dimensional numerical simulation was carried out to analyze the characteristics of the fatigue life and evolution rules of segmental lining. Based on the modified fatigue life formula and metro service life, the optimization design of the buried depth was carried out to determine the most reasonable range of the buried depth. This study provides a valuable reference for safe operation and long-term durability of metro tunnels under high-speed railways.

High-speed rail transportation: key factors for the Australian eastern states

2020 ◽  
Vol 9 (2) ◽  
pp. 174 ◽  
Author(s):  
Koorosh Gharehbaghi ◽  
Kerry McManus ◽  
Kathryn Robson ◽  
David Paterno ◽  
Matt Myers
Keyword(s):  
High Speed ◽  
Rail Transportation ◽  
Key Factors ◽  
High Speed Rail

Deformation and Failure of Pre-Notched Thin Metal Plates Subjected to Confined Blast Loading

2015 ◽  
Vol 782 ◽  
pp. 49-58
Author(s):  
Han Liu ◽  
Peng Wan Chen ◽  
Bao Qiao Guo ◽  
Shao Long Zhang ◽  
Hai Bo Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Deformation ◽  
Blast Loading ◽  
Thin Metal ◽  
Image Correlation ◽  
Deformation And Failure ◽  
Full Field ◽  
3D Digital Image Correlation ◽  
Metal Plates ◽  
Dic Technique

In this paper, the dynamic deformation and rupture of pre-notched thin metal plates subjected to confined blast loading were investigated. The thin copper plates with cross-shape pre-notch were clamped on the end of a confined cylinder vessel by a cover flange. An explosive charge with a mass of 4g was detonated in the vessel center to generate blast load acting on the metal plates. The images of metal plates were recorded by two high-speed cameras. The displacement and strain fields during the deformation and rupture process were measured by using 3D digital image correlation (3D DIC). The effects of pre-notches on the dynamic deformation and rupture of thin metal plates were analyzed. The microstructure of fracture surface was examined The 3D DIC technique is proven to be an effective method to conduct dynamic full-field deformation measurement.

Effects of Carbon Fibre Geogrid Reinforcement on Propagation of Cracking in Pavement and Augmentation of Flexible Pavement Life

2014 ◽  
Vol 891-892 ◽  
pp. 1533-1538 ◽  
Author(s):  
Amir Barry Dizaj ◽  
Hasan Ziari ◽  
Mahmood Ahmadi Nejhad
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Crack Propagation ◽  
Carbon Fibre ◽  
High Speed ◽  
Flexible Pavement ◽  
Fatigue Specimen ◽  
Four Point Bending ◽  
Bending Loading

Most of the distresses in flexible pavement are due to cracking and rutting. Geogrids distribute the street and loads to adequate area and cause augmentation bearing capacity. This project surveys the function of carbon and Glass fiber Geogrids on Delay of Crack propagation in flexible pavement and placement configuration in pavement structure. Four point bending loading applied to beams with dimension 50.8*63.5*381 mm and 6.5 mm tolerance (AASHTO TP8-96). According to the received specimen from cutting slabs of case study toward chart fatigue life, for each condition reinforced and unreinforced beams 3 sample in 4-strain level were experimented. Simulatedrepeated loading with a frequency 10 Hz simulate high-speed traffic was applied to beam fatigue specimen. Based on definition (AASHTO T321-07) assumed achieving to 50% first bending stiffness for end of the fatigue life indicate a significant reduction in the rate of crack propagation in reinforced samples with carbon geogrids compared to unreinforced ones, augmentation service life is up to 3.5fold and placing the geogrid at a one-third depth of overlay thickness from the bottom provide the maximum service life.

Design and Fatigue Life Analysis of a Motorcycle Frame

2014 ◽  
Author(s):  
Massimiliano Gobbi ◽  
Giorgio Previati ◽  
Giampiero Mastinu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Experimental Tests ◽  
Element Model ◽  
Fe Model ◽  
Static Test ◽  
Weld Toe ◽  
Fatigue Life Analysis ◽  
Motorcycle Frame

An off-road motorcycle frame has been analyzed and modified to optimize its fatigue life. The fatigue life of the frame is very important to define the service life of the motorcycle. The strain levels on key parts of the frame were collected during experimental tests. It has been possible to locate the areas where the maximum stress level is reached. A finite element (FE) model of the frame has been developed and used for estimating its fatigue life. Static test bench results have been used to validate the FE model. The accuracy of the finite element model is good, the errors are always below 5% with respect to measured data. The mission profile of the motorcycle is dominated by off-road use, with stress levels close to yield point, so a strain-life approach has been applied for estimating the fatigue life of the frame. Particular attention has been paid to the analysis of the welded connections. A shell and a 3D FE model have been combined to simulate the stress histories at the welds. Two reference maneuvers have been considered as loading conditions. The computed stresses have been used to assess the life of the frame according to the notch stress approach (Radaj & Seeger). The method correlates the stress range in a idealized notch, characterized by a fictitious radius in the weld toe or root, to the fatigue life by using a single S-N curve. New technical frame layouts have been proposed and verified by means of the developed finite element model. The considered approach allows to speed up the design process and to reduce the testing phase.

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