The paper suggests application of an experimental method for the assessment of the dynamic effect of a locomotive underframe on the railway track. The assessment is to be based on spectral analysis of the response of structural elements of the railway track undergoing a shock pulse. Application of digital measuring systems for monitoring of motion of the train is also proposed.

Shock absorbers are intended for developing forces providing the elimination or reduction of the amplitude of cars or their parts fluctuations. On the CIS railroads, the wedge-type shock absorber became the most widespread in trucks of freight cars. In friction shock absorbers, the friction force arises in vertical and horizontal movements of the absorber wedges rubbing on friction plates fixed on the columns of the truck sidewalls. In the article, the modeling of dynamic characteristics of a freight car with the optimized parameters of the wedge-type shock absorber is performed. The modeling is performed by means of the software complex for studying the problems of dynamics of rail vehicles: "The universal mechanism". A dynamic and block diagram of the dynamic model of the car platform, as well as of the mathematical model for studying the friction force and interaction of contact power elements, accounting the creep forces in contact by means of the FASTSIM algorithm based on the Kalker linear theory, is developed. The obtained results of modeling of an eight-wheel freight car with modernized frictional wedges show that in the truck modernization it is expedient to provide additional devices, for example a frictional shock absorber in the central step of suspension. The results of the carried out study prove the expediency of using for the upgraded truck of 18-100 model the design of M1816.06.000 SB, M1819.00.000 SB wedges, at this it is recommended to accept rigidity of elastic elements of these wedges equal to 1.1 kN/mm that is a compromise solution for the safe car movement in the empty and loaded modes.