chapter 28 track-train dynamics. problem lateral forces high center of gravity cars vertical...
Post on 03-Jan-2016
233 Views
Preview:
TRANSCRIPT
Types of Lateral MovementLateral Bending and Bending StressLateral MovementTilt or Twist
Lateral Phenomena
Train Action
Derailment Wheel Climbing Rail Overturning
Brake Action – assumes status of a long and flexible beam in compression, a relatively unstable state
Quick take-up of slack in a long train can also exert lateral pressure
Derailment Causes
Operating Error (Transportation)
Mechanical Error (Mechanical)
Track Error (Engineering)
Or a Combination of Above
~ Conduct Root Cause Analysis ~
L/V Ratio
Ratio of the lateral component to the vertical component of the wheel load.
As ratio increases, tendency to derail increases
More prevalent on jointed trackJoints every 19.5 feet – induced oscillationCar body springs have natural frequency of
oscillation At speeds between 12 and 20 mph
frequencies are additive If square joints – bounce Solutions:
Don’t set sustained speed limits between 12-20 mph
Use snubbing devices on carsUse CWR
Rock & Roll
top related