Determination of the thermal stress state for the composite brake pad of a wagon at operational loads

Abstract

The article provides the results of determining the thermal stress state of the composite brake pad of a wagon. The research is made by means of computer simulation with the finite element method using the SolidWorks Simulation options. The design diagram of the pad includes not only the horizontal loads due to its pressing to the rolling surface of the wheel and the friction force, but also the temperature impact taken equal to 400°C. Since the composite material of the pad is fragile, the Mohr–Coulomb criterion is used as a calculation criterion. It has been found that the maximum stresses occur in the upper part of the pad in the contact area between the back plate and the side plate and do not exceed the permissible values. The article presents the results of the calculation of the thermal stress state of the pad with dual wedge-shaped wear. The study includes the actual parameters of the pad wear determined during operational research. The results of the calculation show that the maximum stresses occur in the back plate of the pad and exceed the permissible values by 19.8%. This is explained by the fact that the useful area of the pad decreases, and therefore its loading increases. The research conducted proves the negative impact of dual wedge-shaped wear on the braking efficiency and the strength of the brake pad. This requires development of measures for eliminating this wear.