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:
Stress distribution in both calculation models analysed (with the consideration of the suspension system and without it).
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.
In conclusion, by implementing suspension systems in railway frame validation, CADE is able to:
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.