The aims of the project are:
-Understanding of the crash phenomena as applied to trains
-use of advanced methods of structural and dynamic analysis of train crash and impact situations
-development and application of modern design methodologies of train cars
-design and production of lightweight and anti-crash fail?safe train structures.
Taking the state-of-the-art in the study and development of impact-resistant rail cars as a starting point and having carried out a characterization of the typical accidents in the field of rail passenger transport, a working methodology and a series of calculation tools have been developed which allows an appropriate design of the structure to be made, taking the performance which is required from it into account.
Throughout the project, both the qualitative and quantitative behaviour which would be demandable from the structures of cars intended for passenger transport has been established.
At the same time, calculation tools for both 2-D and 3-D structures have been developed with the aim of speeding up the design phase in which the amount of calculations is quite considerable. These tools have been extremely useful for executing the initial design stages but not for carrying out the detailed design, due to the great simplifications on which they are based in order to generate the calculation models.
A good correlation has been observed between the results obtained in the structure's simple components and the calculations of these carried out using standard nonlinear Finite Elements Methods. Moreover, a good correlation between the results of the complete structures by different tools developed in the project has been observed.
The calculation tools that have been developed have considerably reduced the time for preparing the calculation models, compared to the commercial tools based on the Finite Elements Method. Further efforts to improve the calculation speed of these tools is still desirable.
Moreover, it should be pointed out that the results obtained with these tools have entailed the use of very simplified models (although they have been based on results obtained from Finite Elements calculations and tests) and therefore their results would only be acceptable within the initial phase of the structure's development. The concept of crushable elements, as explained earlier on, show potentialities to be explored.
In order to optimize the costs related to the development of the train structure, and bearing in mind that the design methodology proposed requires an iterative process, it would be recommendable to carry out an exhaustive study of the structure's simple elements, even by means of tests, as it would be more likely to arrive at an acceptable final solution in this way. Therefore, the final and most expensive phase of the methodology presented would only have to be carried out once.
Further studies are necessary to assess trainset collisions, including rake instabilities and taking into consideration that for many years to come, new crashworthy rakes can collide with existing train rakes. Overriding phenomena and anticlimbing devices is also an important subject to be addressed in a systematic manner.
The different configurations of carbody extremities that have been exploited under this project, particularly new end underframe designs, show that promising improvements can be obtained towards an efficient crashworthiness behaviour of carshell structures.
MK43 OAL Bedford
92086 Paris La Défense