Evaluation of a New Light Rail System by SIMPACK Simulation Wei Huang and Yan Liu National Research Council Canada

October 2014

Contents

• Vehicle / track model • Optimization of track gauge and cant based on curving performance • Identified safety limits of speed on curved track • Stability analysis on tangent track

Vehicle Model

• •

Five modules supported by three bogies Different connection joints between 5 vehicle modules

• •

Accurate SIMPACK Wheel – Rail model Considered elastic wheels effect

Wheel and Rail • Wheelset • • • •

Wheel radius 640 mm Back to back dimension 1378.6 mm Wheel profile designed by OEM Elastic wheel

• Rail • • • • •

Outside Re115 with 0 or 1 in 40 cant Inside - girder rail Gauge point 15.875 mm (5/8”) from Top of Rail Standard gauge 1435.1 mm (56.5”) Gauge on curves to be determined

• Wheel – Rail interface friction 0.5

Animation

Track Model

• Curving analysis on constant curvature part of smooth track • Curve body radius 25 m, 100 m and 150 m • No perturbations • Hunting analysis on smooth tangent track with initial lateral perturbation • Lateral bump peak to peak = 15 mm

Gauge Optimization

Maximum L/V vs. Gauge (R = 25, 100 and 150 m) 1.4 1.2 Curve Radius = 25 m

1

Flange Back, Low Rail, Leading Axle, Module C

Curve Radius = 100 m Curve Radius = 150 m Nadal Limit

Max L/V

0.8

Flange, High Rail, Leading Axle, Module B

0.6 0.4 0.2 0 1.436

1.4365

1.437

Gauge (m)

1.4375

1.438

Effect of Elastic Wheel on Back to Back Spacing Lateral wheel deformation = Increase of back to back spacing (“+” as increase and “-” as decrease of back to back spacing) Curve Radius = 25 m

Curve Radius = 25 m

0.8 Left and Right Wheel Total Lateral Deformation (mm)

0.6 0.4 0.2 0 -0.2 0

20

40

-0.4 -0.6 -0.8 -1

60

Left and Right Wheel Lateral Force Difference (kN)

30 20 10 0 -10

0

10

20

30

40

-20 -30 -40 -50

-1.2 Time (s)

Time (s)

Lateral Wheel Deformation and Forces, Leading Axle, Module C (R = 25 m, Speed = 15 km/h, Gauge = 1.437 m)

50

60

Safety Limit of Speed

Maximum L/V vs. Speed (R=25m, Gauge = 1.437 m, Wheel - Rail Friction = 0.5)

Curve Radius = 25 m 1.3

Max L/V

1.2 1.1 1 0.9

Max L/V Nadal Limit

0.8 15

20

25

Speed (km/h)

30

Maximum L/V vs. Speed (R=100m, Gauge = 1.437 m)

Curve Radius = 100 m 1.6

Max L/V

1.4 Max L/V Nadal Limit

1.2 1 0.8 0.6 0.4 30

35

40

45

50

Speed (km/h)

55

60

Maximum L/V vs. Speed (R=150m, Gauge = 1.437 m)

Curve Radius = 150 m 1.6

Max L/V

1.4 Max L/V Nadal Limit

1.2 1 0.8 0.6 0.4 35

40

45

50

55

Speed (km/h)

60

65

Cant Effect

Maximum L/V vs. Gauge (R=25m, V = 15 km/h, Cant = 0 and 1:40)

Curve Radius = 25 m 1.3 1.2

Max L/V

1.1

Cant = 1:40 Cant = 0 Nadal Limit

1 0.9 0.8 0.7 0.6 1.436

1.4365

1.437

Gauge (m)

1.4375

1.438

Superelevation Effect

Maximum L/V vs. Speed (R=25m, Gauge = 1.437 m, SuperElevation = - 50 mm) Curve Radius = 25 m 1.4

Max L/V

1.3 1.2 1.1

Super Elevation = -50 mm Super Elevation = 0 Nadal Limit

1 0.9 0.8 15

20

25

Speed (km/h)

30

Maximum L/V vs. Speed (R=25m, Superelevation = -50mm, Gauge = 1436.5 mm and 1437 mm)

Curve Radius = 25 m, Super Elevation = -50mm 1.4 1.3

Max L/V

1.2 1.1 Gauge = 1436.5 mm Gauge = 1437 mm Nadal Limit

1 0.9 0.8 0.7 15

20

25

Speed (km/h)

30

Grade Effect

Maximum L/V vs. Speed (R=25m, Gauge = 1.437 m, Super Elevation = -50mm, Grade = 0 and -5 %)

Curve Radius = 25 m, Super Elevation = -50 mm 1.4

Max L/V

1.3 1.2 Slope = - 5 % Slope = 0 Nadal Limit

1.1 1 0.9 15

20

25

Speed (km/h)

30

Minimum Vertical Load Ratio vs. Speed (R=25m, Gauge = 1.437 m, Super Elevation = -50mm, Grade = -5 %)

Minimum Vertical Load Ratio(%)

Curve Radius = 25 m 18 16 14 12 10 8 6 4 2 0 15

17.5

20 Speed (km/h)

22.5

25

Maximum Speed on Tangent Track

Wheel Lateral Displacement vs. Time (Tangent Smooth Track, Gauge = 1.437 m, Cant = 0 )

Cant = 0 -0.012

Lateral Wheel Deviation (m)

0

2

4

6

8

-0.013

-0.014

-0.015 -0.016

-0.017 70 km/h 75 km/h

-0.018

80 km/h -0.019

Time (s)

10

Wheel Lateral Displacement vs. Time (Tangent Smooth Track, Gauge = 1.437 m, Cant = 1:40)

Cant = 1:40 -0.01

Lateral Wheel Deviation (m)

-0.011

0

2

4

6

115 km/h -0.012 118 km/h -0.013 -0.014 -0.015 -0.016 -0.017 -0.018 -0.019 -0.02

Time (s)

8

10

Conicity, 0 and 1/40 Cant OEM

OEM

Conclusion about Gauge • To achieve the best load sharing effects of girder rail, sharp curve requires a gauge narrower than shallow curve • This is because the sharper curves generate larger angle of attack, resulting in larger flange back fattening and therefore making the “effective” wheel back to back dimension narrower than the shallower curves • Recommended gauges from dynamic simulation for different curves are • 1436.5 mm for curve radius between 25 m and 100 m • 1438 mm for curve radius between 100 m and 150 m • However 1437 mm gauge can be a good compromise for all curves between 25 m to 150 m, assuming 0 cant on these curves and no negative superelevation

Conclusion about Cant • Wheel profile was designed for 0 cant. Dynamic simulation results support that the better curving performance can be achieved with zero cant than 1/40 cant on curve with the girder rail section (curve radius between 25 m and 150 m) • On tangent track with Re115 rail section, the present study found that 0 cant will move the wheel - rail contact point toward to gauge corner and result in a high conicity. Dynamic simulation shows that the critical hunting speed is 70 kph for 0 cant and 115 kph for 1/40 cant • Therefore based on the present analysis it is preferred • Zero cant on curves with radius between 25 m and 150 m • 1/40 cant on tangent track

Conclusion about Speed • The maximum operation speeds on curves recommended by OEM are based on 100 mm (4 inch) cant deficiency, i.e. • 15 kph for 25 m radius curve • 29 kph for 100 m curve • 36 kph for 150 m curve • Simulation shows the following safety limits based on Nadal limits • 25 kph for 25 m radius curve • 60 kph for 100 m curve • 65 kph for 150 m curve • Therefore the dynamic simulations indicate that the maximum operation speeds based on 100 mm cant deficiency have good safety margins.

Other Findings • Negative superelavation has a considerable impact to safety margin. The cant deficiency in the case of negative superelevation is therefore suggested to be 50 mm (2 inches). • 5% Grade was found to have a significant impact on the curving performance.