ECS Weld Geometry Standards FORCEBASED ASSESSMENT OF WELD

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

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

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

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

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

ECS Weld Geometry Standards FDyn Inclination 40 km/h 5 k. N 3. 2 mrad 80 km/h 15 k. N 2. 4 mrad 140 km/h 35 k. N 1. 8 mrad 200 km/h 65 k. N 0. 9 mrad 300 km/h 140 k. N 0. 7 mrad 100 km/h 50 k. N 1. 4 mrad Total force in principle 225 k. N Velocity Implemented in RAILPROF HH HSL Conventional FORCE-BASED STANDARDS QI=1 www. esveld. com www. rail. tudelft. nl 6

ECS Weld Geometry Standards NEW VERSUS OLD NORM Versine Inclination Velocity [mrad] [mm] 40 km/h 0. 96 3. 2 80 km/h 0. 72 2. 4 140 km/h 0. 54 1. 8 200 km/h 0. 27 0. 9 300 km/h 0. 21 0. 7 Old Norm 0. 30 1. 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. www. esveld. com www. rail. tudelft. nl 7

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

ECS Weld Geometry Standards ASSESSMENT OLD AND NEW ON PRORAIL RP 002949 RP 002432 Old norm: Rejected, New: OK Old norm: OK, New: Rejected RP 003125 RP 002945 Old norm: Rejected, New: OK www. esveld. com Old norm: Rejected, New: Rejected www. rail. tudelft. nl 9

ECS Weld Geometry Standards SELECTION ON PRORAIL 100 welds per group 1. 8 mrad (140 km/h) Limit at 80 km/h www. esveld. com www. rail. tudelft. nl 10

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

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

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

ECS Weld Geometry Standards AXLE BOX ACCELERATIONS Dynamic amplification less than 2. 2 www. esveld. com www. rail. tudelft. nl 14

ECS Weld Geometry Standards PRACTICAL IMPLEMENTATION 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. www. esveld. com www. rail. tudelft. nl 15

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

ECS Weld Geometry Standards PDA SCREEN V = 140 km/h QI = 1. 06 QI uniquely shows where to grind www. esveld. com www. rail. tudelft. nl 17

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

ECS Weld Geometry Standards 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. www. esveld. com www. rail. tudelft. nl 19