Metro Train Simulation

Coupler Force Calculation

Coupler Force Calculation :

A coupler is a mechanism used to connect the different type of coaches in a train. During operation of a train, forces are transferred from one coach to another through the coupler. The value of coupler force between coaches mainly depends upon the acceleration of the train, mass of motor coach & trailer coach, number of motor coach & trailer coach in a basic unit, the position of isolated basic units in a train and the speed of a train. However, instant value of maximum coupler force, mainly depends upon the coupler slack & cushion, track irregularities and jerk limit of the train & its value may be much higher than the coupler force in the constant tractive effort zone. The value of coupler force at higher speed is less than that of at lower speed. Constant up gradient does not affect the value of coupler force, however the value of starting acceleration at up gradient track will be low. Please input the following parameters for coupler force calculation :





# NOTE : Please read para 'Limitations of online coupler force simulation software tool'. This is an demo software and results of online coupler force simulation software tool may have some error due to these limitations. However, our offline software tools do not have such limitations and provide much accurate simulation results. For detail description of technnical terms used in this simulation tool, please read 'Definitons' & 'Performance Parameters' sections of this website.

Tractive Effort, Train Resistance Vs Speed Graph of Train :

coupler-force

In the above graph:


OA:
Value of Max. TE of train in KN
AB:
Constant Tractive Effort Zone
BC:
Quadrant portion of TE vs Speed graph; wherein, generally TE is inversely proportional of the speed.
CD:
Quadrant portion of TE vs Speed graph; wherein, generally TE is Inverse Quadratic of the speed.
OE:
Power zone start speed of TE-Sp. graph
OF:
Power zone end speed of TE-Sp. graph

Limitations of online Coupler force simulation software :

1. Effect of grade change, curve & track irregularities on coupler force is not considered.
2. The effect of jerk limit, coupler slack and cushioning devices on the magnitude of coupler forces can not be calculated through demo software.
3. Value of coupler force at higher speed with unequal passenger loading can not be calculated.
4. Effect of rotating mass, emergency braking on coupler force is not considered.
5. Coupler force during braking mode can not be calculated.