ECS Weld Geometry Standards FORCE-BASED ASSESSMENT OF WELD GEOMETRY Coenraad Esveld Delft University of Technology Esveld Consulting Services Delft University of Technology Esveld Consulting Services

ECS Weld Geometry Standards DAMAGE DUE TO POOR WELD GEOMETRY

ECS Weld Geometry Standards 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

ECS Weld Geometry Standards The dynamic contact force as a function of the first time derivative: VELOCITY APPROACH

ECS Weld Geometry Standards l QI ≤ 1: Accepted l QI > 1: Rejected l QI ≤ 1: Accepted l QI > 1: Rejected QUALITY INDICES (QI)

ECS Weld Geometry Standards 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

ECS Weld Geometry Standards NEW VERSUS OLD NORM Velocity Versine [mm] Inclination [mrad] 40 km/h km/h km/h km/h km/h Old Norm For 80 km/h the new norm is 2.4 times more favorable than the old norm, provided short waves have been ground off.

ECS Weld Geometry Standards 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

ECS Weld Geometry Standards ASSESSMENT OLD AND NEW ON PRORAIL RP RP RP RP Old norm: Rejected, New: OK Old norm: OK, New: Rejected Old norm: Rejected, New: Rejected

ECS Weld Geometry Standards SELECTION ON PRORAIL 1.8 mrad (140 km/h) Limit at 80 km/h 100 welds per group

ECS Weld Geometry Standards OLD VERSUS NEW STANDARDS

ECS Weld Geometry Standards Low correlation force and versine Low correlation force and versine High correlation force and QI High correlation force and QI CALCULATED DYNAMIC FORCES

ECS Weld Geometry Standards Dynamic force linear with QI Dynamic force linear with train speed Dynamic force linear with train speed CALCULATED DYNAMIC FORCES

ECS Weld Geometry Standards AXLE BOX ACCELERATIONS Dynamic amplification less than 2.2

ECS Weld Geometry Standards 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

ECS Weld Geometry Standards PRACTICAL IMPLEMENTATION

ECS Weld Geometry Standards PDA SCREEN V = 140 km/h QI = 1.06 V = 140 km/h QI = 1.06 QI uniquely shows where to grind

ECS Weld Geometry Standards DESKTOP SOFTWARE  All data and graphs can be shown on a PC;  Results in pdf-format can directly be ed to customer.  All data and graphs can be shown on a PC;  Results in pdf-format can directly be ed to customer.

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. 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.