Abstract: A finite element model of a single pad-wheel tread brake system for railway freight cars is established by using ABAQUS software. A complex eigenvalue analysis of the brake system is performed. The occurrence propensity of brake squeal is evaluated on the basis of positive and negative of the real parts of eigenvalues. If there are one or more positive real parts, the system is considered to have the propensity of squeal occurrence. In the ABAQUS approach, the direct contact coupling at the wheel/pad interface is applied to obtaining normal contact forces and there is no need to introduce contact springs at the interface. The approach is easily used to establish a non-flat sliding contact model for squeal. By using the ABAQUS finite element model, effects of the friction coefficient, pressure angle between the normal line of pad and horizontal line, normal force acting on a pad and rotation direction of wheel on squeal occurrence are studied. The results show that the pressure angle has a distinct effect on the occurrence of squeal. When the pressure angle is equal to 5°, the propensity of squeal generation is greatly suppressed. The analysis results also demonstrate that the propensity of squeal formation increases with increasing friction coefficient or normal force. It is also found that the clockwise rotation of wheel causes squeal more easily than the counter clockwise rotation of wheel does.

Key words: Brake, Finite element, Friction, Noise, Squeal