STRUCTURAL ANALYSIS OF RAILWAY ROLLING STOCK INCORPORATING SUSPENSION SYSTEM

Advantages of incorporating the suspension system to finite element analysis

CADE normally uses the Finite Element Method (FEM) to undertake simulation modelling and analysis of complex structural elements. This method is often used to analyse critical elements and mechanical parts, whose performance may be conditioned by other mechanical elements or systems.

In the structural analysis of railway rolling stock, specifically in frame structures of vehicles, the consideration of suspension systems (bogies) in its Finite Element Analysis becomes highly relevant: it allows to characterise (in the most realistic way possible) the bogie rigidity transmitted to the frame structure, according to the requirements of the standard “UNE-EN 12663 (2014) Structural requirements of railway vehicle bodies”.

The difference between the consideration or not consideration of the suspension system in the finite element analysis can be easily quantified. The results can be compared by analyzing the simulation of a multi-axle railway frame, applying the finite element method and using ANSYS software. For this purpose, two calculation models must be compared:

  • Model implementing the suspension system.
  • Model without implementation of the suspension system.

RESULTS IN STRUCTURAL ANALYSIS OF RAILWAY ROLLING STOCK

Equivalent von Mises stress (MPa)

Stress distribution in both calculation models analysed (with the consideration of the suspension system and without it).

Model implementing the suspension system

l modelo de elementos finitos (distribución de tensiones considerando el sistema de suspensión)
Detalle del modelo de elementos finitos (distribución de tensiones considerando el sistema de suspensión)

Model without implementation of the suspension system

l modelo de elementos finitos (distribución de tensiones sin considerar el sistema de suspensión)
detalle del model modelo de elementos finitos (distribución de tensiones sin considerar el sistema de suspensión)

When validating this type of frame, the stress results might be the most relevant indicators. Therefore, not to incorporate the suspension systems in finite element analysis could be a too conservative assumption, from the structural integrity point of view, and unnecessarily increase material and manufacture costs.

CONCLUSIONS OF THE STRUCTURAL ANALYSIS

In conclusion, by implementing suspension systems in railway frame validation, CADE is able to:

  • Lighten railway structures, reducing material and manufacturing costs.
  • Obtain safer railway structures, because it is possible to identify buckling modes (not found with finite element analysis without bogies consideration) and at the same time, to obtain higher safety factors against buckling.

FURTHER INFORMATION

What is a 'bogie'?

A bogie (also called railroad track or wheel truck) is the suspension system placed underneath a railway vehicle.

It has a primary suspension (which transmits efforts between the wheels and the bogie) and a secondary suspension (which transmits efforts between the bogie and the frame of the railway vehicle). Both suspensions have a series of springs and shock absorbers that allow to transmit efforts between the wheels, the bogie and the railway frame.

Sistema de suspensión en estructuras ferroviarias utilizado en modelo de elementos finitos
Bastidor ferroviario utilizado en las simulaciones con modelo de elementos finitos

Advanced Engineering Services

CADE has more than 15 years of experience developing mechanical and industrial engineering projects. During this time, CADE has become a pioneer in the use of computer-aided engineering (CAE) applications and provides structural analysis, simulation modelling, engineering and consulting services, finite element analysis (FEA) and computational fluid dynamics (CFD) in different equipment, elements and structures.

CADE Engineered Technologies

For any further information about advanced engineering services of design and consultancy for railway frames, please complete the following form:
Scroll Up