IMPROVEMENT OF THE TECHNIQUE TO EVALUATE THE VIBRATION STRAIN OF THE PASSENGER CAR BODY

Abstract

The analysis of domestic and foreign studies in the field of evaluating the dynamic strain of passenger car bodies allowed us to find out that most of the methods are based on the evaluation of the vibration strain. An improved method is proposed to consider to evaluate the vibration strain of the car. As a method for determining the body's structural properties, a mathematical modeling method is proposed. On the basis of this method, a finite element model of the body is developed, which natural frequencies and forms of vibrations are calculated by Lanczos method. The results obtained by finite element model are compared with the data obtained during tests conducted by the Testing Center TIV. The discrepancy between the calculation and the experiment is 11.85%, which indicates the adequacy of the created finite element model. To define the dynamic load of the body the developed finite element model was reduced to four variants, each of which is transformed into a spatial hybrid dynamic model. The results obtained during the calculation are compared with the values of the running tests of the car. The analysis of the data shows that the fourth variant of the finite element model of the passenger car body, which takes into account the real distribution of the mass of the internal equipment elements and the interior has values more approximate to the data obtained during running tests. Based on this, it can be concluded that this option is most suitable for calculating the stiffness characteristics of the passenger car body.