3. Simulation of post-derailment vehicle behavior

  • RTRI developed a vehicle behavior simulation that can be used to quantitatively evaluate the effects of a guard to prevent secondary abnormalities after derailment.
  • This simulation method enables the comprehensive investigation of the effects of countermeasures for vehicles, tracks and structures during earthquakes.

For scenarios in which railway vehicles are derailed by events such as large-scale earthquakes, countermeasures to prevent derailed cars from deviating onto the opposite track or off the rail track area are an important part of minimising related damage. When selecting and evaluating such secondary-abnormality countermeasures, it is essential to quantify their effects using analysis tools because it allows various influences such as running on ballast or vibrational displacement of structures to be taken into account. Accordingly, the RTRI developed a post-derailment vehicle behavior simulation model that can be used to quantitatively evaluate the effects of a secondary-abnormality prevention guard as a countermeasure.

As a technique to effectively represent the complicated large-scale vehicle-track contact problems after derailment with a small analysis load, the RTRI proposed a rigid body section model that represents wheels after derailment and a track structure with the prevention guard using a trapezoid and a rectangular parallelepiped (Fig.1) to allow practical analytical evaluation.

Incorporating this technique into the dynamic interaction analysis program for Shinkansen vehicles and railway structures (DIASTARS) enabled the effects of countermeasures for vehicles, tracks and structures to be comprehensively investigated (Fig. 2), and also allowed the impact force between the wheels and the prevention guard to be quantified.

In future implementation, RTRI will utilize this evaluation method to plan countermeasures for entire railway lines.

  • fig 1
    Fig. 1 Dynamic model of wheels after derailment and a secondary-abnormality prevention guard
  • fig 2
    Fig. 2 Example of post-derailment vehicle behavior analysis