Kinematic analysis of a freight cars bogie
The article is devoted to development of a mathematical model of a freight car bogie of a rail car 18-100. Bogies unsprung part made of two wheel pairs with boxes and two side frames is viewed as a modified rigid body with inner degree of freedom defined by relative virtual displacement of systems bodies within axle box. For description of deformation of a bogies plane quadrangle during movement parameters of a bogies skew named as shift and deplanation are described. As a result bogies affine reference stake called natural is designed and corresponding metric tensor that defines a bogies geometric space is developed. Internal and external nonholonomic constraints of a bogie and conditions of a constant bogies movement on rail track are described. Variable tensor of a bogies inertia as a modified rigid body is given.