Abstract
When a railway vehicle overturns in accidents, the shape of cross section of the carbody is likely to be transformed to the parallelogram by the side impact. In the case, the survival space for passengers and crews may be decreased by the deformation. To secure the survival space, the "ring structure" is composed by uniting sub-frames attached inside the carbody as non-structural members together. Empirical tests and FE analyses were performed to verify the possibility of improving the rail carbody strength against the load from the body side.
