DEVELOPMENT OF A COLLISION ENERGY ABSORBER OF A PASSENGER TRAIN
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INTRODUCTION
The subject of this paper is research of the characteristics of elements of shock
absorbers of collision energy of passenger trains operating on the principle of tube
compression into a ring with a reduced diameter. The shock absorber role is to use up
most of the collision energy in a controlled deformation in order to protect the structure
behind the elements as much as possible from permanent deformations and thus protect
the passengers and passenger coach.


Quasi-static investigation. Quasi-static investigations were performed on a
LITOSTROJ hydraulic press where a maximal force of 2500 KN can be realized. During
experimental research the compression distance and force were measured. Measurement
of the compression distance was realized using two potentiometer movement indicators
of the PM2S 150 type installed in parallel. With the purpose of eliminating possible
slanting of supporting surfaces (panels) the average value of movement of two indicators
is taken. Measurement of the compression force was performed using a special indicator
constructed on the base of measuring tapes connected into a full bridge where
temperature self-compensation was accomplished.


RESULTS AND DISCUSSION
After the investigations were complete the recorded data was analyzed and
diagrams describing the dependence of the force on the press as a function of the piston
operation were formed.


Review of the realization of absorber parameters. Analysis of the diagrams
given above gave parameters according to which an evaluation of the suitability of this
type of element for energy absorption was given: average force – Fav, maximal force –
Fmax and compression work – W.


CONCLUSION
According to the parameters obtained from experimental investigations one can
conclude that absorption elements working on the principle of tube radius changes
(narrowing) are suitable for the planned application. A characteristic noted for all
investigated samples is a gradual force increase, passive characteristic, good utilization
of the tube material and also small ratio between maximal and average force.