TY - JOUR
T1 - Methods to mitigate railway premium fastening system spike fatigue failures using finite element analysis
AU - Dersch, Marcus S.
AU - Khachaturian, Christian
AU - Edwards, J. Riley
N1 - Funding Information:
This research effort is funded by the Federal Railroad Administration (FRA), part of the United States Department of Transportation (US DOT). This work was also supported by the National University Rail Center, a U.S. Department of Transportation Office of the Assistant Secretary for Research and Technology Tier 1 University Transportation Center. The material in this paper represents the position of the authors and not necessarily that of sponsors. The authors also would like to thank Dr. Carmen Sandhaas for supplying literature as well as the base UMAT code used for this paper, Brad Kerchof for his continued insight and comments related to broken spikes, as well as Liam Bots for his help in collecting and preparing data for this paper. Finally, the authors acknowledge the following project industry partners for supplying insight, recommendations, and materials to this study: Norfolk Southern Corporation; Lewis Bolt & Nut; and Pandrol USA.; Vossloh Fastening System North America. J. Riley Edwards has been supported in part by the grants to the UIUC Rail Transportation and Engineering Center (RailTEC) from CN and Hanson Professional Services. The authors confirm contribution to the paper as follows: study conception and design: Marcus Dersch; data collection: Marcus Dersch and Christian Khachaturian; analysis and interpretation of results: Marcus Dersch, J. Riley Edwards, and Christian Khachaturian; draft manuscript preparation: Marcus Dersch, J. Riley Edwards, and Christian Khachaturian. All authors reviewed the results and approved the final version of the manuscript.
Funding Information:
This research effort is funded by the Federal Railroad Administration (FRA), part of the United States Department of Transportation (US DOT). This work was also supported by the National University Rail Center, a U.S. Department of Transportation Office of the Assistant Secretary for Research and Technology Tier 1 University Transportation Center. The material in this paper represents the position of the authors and not necessarily that of sponsors. The authors also would like to thank Dr. Carmen Sandhaas for supplying literature as well as the base UMAT code used for this paper, Brad Kerchof for his continued insight and comments related to broken spikes, as well as Liam Bots for his help in collecting and preparing data for this paper. Finally, the authors acknowledge the following project industry partners for supplying insight, recommendations, and materials to this study: Norfolk Southern Corporation; Lewis Bolt & Nut; and Pandrol USA.; Vossloh Fastening System North America. J. Riley Edwards has been supported in part by the grants to the UIUC Rail Transportation and Engineering Center (RailTEC) from CN and Hanson Professional Services.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/3
Y1 - 2021/3
N2 - Railroad track fasteners work as a system, in conjunction with the sleeper, to maintain gauge, transmit loads, and resist lateral and longitudinal rail movement. Timber sleeper elastic fastening systems have shown benefits by preventing rail rollover derailments and reducing spike killing. However, these systems have experienced broken spike failures leading to at least 10 derailments over the past 20 years. Recent studies focusing on the cause of the failures have indicated that the spikes fail in fatigue and these fatigue failures are driven by the addition of longitudinal loads the spikes carry. Further, due to the nature of the elastic fastener, the wave-action of the rail separates the plate from the sleeper, as opposed to the rail from the plate, thus eliminating the load transferred by friction. This study quantifies the effect of fastening system design changes on spike stress and the load required to exceed the spike endurance limit. Specific design changes investigated in this study include increasing spike cross-sectional area, comparing spike type (cut vs screw), varying the spike load location, controlling the development of friction between the sleeper and plate, varying spike engagement and finally, adjusting the quantity of spikes at a given rail seat. Finite element analysis (FEA) was used to quantify these effects and multiple 3D models were developed and used. Results indicate that the two most effective methods to reduce spike stress and increase the required load to exceed the spike's endurance limit, and thus mitigate spike fatigue failures, would be to ensure spike engagement between the plate and spikes and develop friction between the plate and sleeper (e.g. add spring washers, etc.). Future fastening system designs can incorporate these, and other findings, to mitigate spike fastener failures to ensure the full value of timber sleeper elastic track fastening systems is realized.
AB - Railroad track fasteners work as a system, in conjunction with the sleeper, to maintain gauge, transmit loads, and resist lateral and longitudinal rail movement. Timber sleeper elastic fastening systems have shown benefits by preventing rail rollover derailments and reducing spike killing. However, these systems have experienced broken spike failures leading to at least 10 derailments over the past 20 years. Recent studies focusing on the cause of the failures have indicated that the spikes fail in fatigue and these fatigue failures are driven by the addition of longitudinal loads the spikes carry. Further, due to the nature of the elastic fastener, the wave-action of the rail separates the plate from the sleeper, as opposed to the rail from the plate, thus eliminating the load transferred by friction. This study quantifies the effect of fastening system design changes on spike stress and the load required to exceed the spike endurance limit. Specific design changes investigated in this study include increasing spike cross-sectional area, comparing spike type (cut vs screw), varying the spike load location, controlling the development of friction between the sleeper and plate, varying spike engagement and finally, adjusting the quantity of spikes at a given rail seat. Finite element analysis (FEA) was used to quantify these effects and multiple 3D models were developed and used. Results indicate that the two most effective methods to reduce spike stress and increase the required load to exceed the spike's endurance limit, and thus mitigate spike fatigue failures, would be to ensure spike engagement between the plate and spikes and develop friction between the plate and sleeper (e.g. add spring washers, etc.). Future fastening system designs can incorporate these, and other findings, to mitigate spike fastener failures to ensure the full value of timber sleeper elastic track fastening systems is realized.
KW - Broken spikes
KW - Fastening system design
KW - Fatigue failure
KW - Finite element analysis
KW - Stress mitigation
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U2 - 10.1016/j.engfailanal.2020.105160
DO - 10.1016/j.engfailanal.2020.105160
M3 - Article
AN - SCOPUS:85097756908
SN - 1350-6307
VL - 121
JO - Engineering Failure Analysis
JF - Engineering Failure Analysis
M1 - 105160
ER -