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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 1 FORCE-BASED ASSESSMENT OF WELD GEOMETRY Coenraad Esveld Delft University of Technology Esveld Consulting Services Delft University of Technology Esveld Consulting Services

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 2 DAMAGE DUE TO POOR WELD GEOMETRY

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 3 EXISTING WELD GEOMETRY STANDARDS For example Versine: 0 < p < 0.3 mm For example Versine: 0 < p < 0.3 mm p < 0.3 mm Grind off top

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 4 The dynamic contact force as a function of the first time derivative: VELOCITY APPROACH

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 5 l QI ≤ 1: Accepted l QI > 1: Rejected l QI ≤ 1: Accepted l QI > 1: Rejected QUALITY INDICES (QI)

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 6 FORCE-BASED STANDARDS VelocityF Dyn Inclination 40 km/h 5 kN3.2 mrad 80 km/h15 kN2.4 mrad 140 km/h 35 kN 1.8 mrad 200 km/h65 kN0.9 mrad 300 km/h140 kN0.7 mrad 100 km/h50 kN1.4 mrad QI=1 Conventional HSL HH Implemented in RAILPROF Total force in principle 225 kN

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 7 NEW VERSUS OLD NORM Velocity Versine [mm] Inclination [mrad] 40 km/h0.963.2 80 km/h0.722.4 140 km/h 0.54 1.8 200 km/h0.270.9 300 km/h0.210.7 Old Norm0.301.0 For 80 km/h the new norm is 2.4 times more favorable than the old norm, provided short waves have been ground off.

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 8 LATERAL GEOMETRY STANDARDS VelocityVersine 40 km/h1.0 mm 80 km/h0.7 mm 140 km/h0.5 mm 200 km/h0.5 mm 300 km/h0.5 mm QI=1 Implemented in RAILPROF

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 9 ASSESSMENT OLD AND NEW ON PRORAIL RP002432 RP002945 RP002949 RP003125 Old norm: Rejected, New: OK Old norm: OK, New: Rejected Old norm: Rejected, New: Rejected

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 10 SELECTION ON PRORAIL 1.8 mrad (140 km/h) Limit at 80 km/h 100 welds per group

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 11 OLD VERSUS NEW STANDARDS

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 12 Low correlation force and versine Low correlation force and versine High correlation force and QI High correlation force and QI CALCULATED DYNAMIC FORCES

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 13 Dynamic force linear with QI Dynamic force linear with train speed Dynamic force linear with train speed CALCULATED DYNAMIC FORCES

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 14 AXLE BOX ACCELERATIONS Dynamic amplification less than 2.2

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 15 Procedure: l Sample weld geometry with digital straightedge l Filter measured signal l Determine 1 st derivative (inclination) l Normalize with intervention value for line speed l Calculate QI. l QI < 1: OK, otherwise: grinding. Procedure: l Sample weld geometry with digital straightedge l Filter measured signal l Determine 1 st derivative (inclination) l Normalize with intervention value for line speed l Calculate QI. l QI < 1: OK, otherwise: grinding. PRACTICAL IMPLEMENTATION

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 16 PRACTICAL IMPLEMENTATION

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 17 PDA SCREEN V = 140 km/h QI = 1.06 V = 140 km/h QI = 1.06 QI uniquely shows where to grind

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 18 DESKTOP SOFTWARE All data and graphs can be shown on a PC; Results in pdf-format can directly be emailed to customer. All data and graphs can be shown on a PC; Results in pdf-format can directly be emailed to customer.

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ECS Weld Geometry Standards www.esveld.com www.rail.tudelft.nl 19 CONCLUSIONS 1.Theory based on first derivative works fine in practice; 2.Steel straightedge is absolutely inadequate; 3.Instead electronic straightedges with QI (RAILPROF); 4.High correlation of force and QI, low correlation with versine; 5.With RAILPROF QI measurement: You see what you do; Higher quality; Less rejections provided short waves are ground properly (also negative welds allowed); Extension of life cycle. 1.Theory based on first derivative works fine in practice; 2.Steel straightedge is absolutely inadequate; 3.Instead electronic straightedges with QI (RAILPROF); 4.High correlation of force and QI, low correlation with versine; 5.With RAILPROF QI measurement: You see what you do; Higher quality; Less rejections provided short waves are ground properly (also negative welds allowed); Extension of life cycle.

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