Calculation of Critical Crack Size of Repair Welded Rail

Hyun Kyu Jun; Jung Won Seo

doi:10.4028/www.scientific.net/AMR.891-892.1175

Paper Titles

Fretting Fatigue Testing of Carburized Alloy Steel in Very High Cycle Regime Using an Ultrasonic Torsional Fatigue Testing Machine
p.1152

On the Evaluation of the Stress State in Rail Head for Assessing Fatigue Resistance
p.1157

Fatigue in Railway Components - Understanding vs. Resolution
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Rail Bogie Structural Assurance
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Calculation of Critical Crack Size of Repair Welded Rail
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Fatigue Analysis of the Rail Underhead Radius under High Axle Load Conditions
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Probabilistic Damage Tolerance Analysis for General Aviation
p.1191

Material Scatter in Crack Growth Rates of 7075-T7351 under Spectrum Loading
p.1197

A Detailed Evaluation of the Effects of Bulk Residual Stress on Fatigue in Aluminum
p.1205

HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 891-892Calculation of Critical Crack Size of Repair...

Calculation of Critical Crack Size of Repair Welded Rail

Abstract:

Repair of damaged rail surface by overlay welding is the common rail maintenance method. But the discontinuity in material between base and weld brings initiation of cracks and they causes a rail fracture. Unfortunately, such cracks are hard to detect on site because the weld boundary prevents the echo signals penetration by reflection. So estimation of the critical crack size (CCS) has been a critical issue in railroad industry to prevent a rail from sudden fracture. In this study, we calculated the critical size of crack which was initiated and propagated underneath of the overlay welded rail by applying linear elastic fracture mechanics. For this purpose, we measured the maximum load carrying capacities of cracked UIC60 by inverted 3 point bend tests and checked the feasibility of the finite element (FE) analysis procedure. We could find the correlation in crack size between the test and 3D FE analysis results and applied the proposed 3D FE analysis model to calculate the CCS of a rail. We calculated the stress intensity factors on cracked rail by increasing the size of crack until the rail broke. The CCS was calculated as around 30.0 mm under the normal railway service operating condition.