Tests on structures

This is a study case about tests on structures that our laboratory the AEF can perform under  COFRAC accreditation EN 17025

DESCRIPTION

Rail vehicle body structures have to withstand the extremely heavy loads that may occur on a limited number of occasions during operations and a wide range of dynamic loads of varying scale (in service fatigue). The effects of these loads can be most clearly seen at a number of critical points on the vehicle structure. Both the ability to withstand these exceptional loads and fatigue strength have to be demonstrated during tests.

Qualification procedures for rail vehicle structures (locomotives, coaches, wagons) include static strength tests, which have to be carried out to demonstrate that the structures concerned are not liable to permanent deformation or fracture. These tests are often performed on a parallel to digital simulation. The conditions under which they are conducted are set out in European and/or international standards.

Our laboratory is able to perform these tests under its COFRAC EN 17025 accreditation. We can boast the following equipment and facilities for the purpose:
Essais de structures

Ballast weights ranging from 20 kg pigs to blocks of lead weighing up to 6 tonnes. By using these weights it is possible to simulate a variety of structure loading configurations (empty, under normal and under exceptional loads).

Tests on structures

Jacks that can be used to simulate all types of lifting or raising operations (either in the maintenance sheds or elsewhere) to check structure behaviour. These operations consist of raising the body shell by positioning the jacks at the normal lifting points (bearers and spindles)

A test rig capable of producing compression loads of up to 3,600 kN and tensile loads of up to 2,200 kN by means of two hydraulic jacks each with a stroke of 800 mm. These loads can be applied and/or absorbed as reaction forces at the buffers, in the coupler, at the obstacle deflector or at different levels (floor, waist, longitudinal roof member, etc.) depending on the type of structure. Other smaller jacks can also be used to check the performance of the shock absorber supports or any other structural components.
During the tests, a large number of checks and measurements are conducted to ensure that the body shell is compliant with requirements. By way of example, mention can be made of the checks into surface flatness, measurement of compressive and tensile loads, micro-deformation using strain gauges, variations in deflection in the two sole bars and the longitudinal roof member, in body length, frame diagonals (windows, doors, traps).
We can also take charge of tool design and manufacture. This may require three-dimensional modelling of the structure on the rig.
Nos systèmes de mesure sont dotés de logiciel de dépouillement automatique permettant l’analyse des résultats en temps réel.
Our measurement systems are backed by software for automatic real-time processing of the results obtained. Where the logistics aspects are concerned, the structures to be tested can be delivered as outsize loads by road, or by rail. We have the necessary equipment for unloading at our testing plant.

In cases where the client is unable to send the service bogies with the structure to be tested, we can provide the requisite replacements for testing purposes.

Essais de structure

 

Consult our catalogue

Railway Expertise and Testing