Chain Link Deformation in the Nonlinear Dynamics of Tracked Vehicles

Abstract

In this investigation, a computational finite element procedure for the deformation and stress analysis of the chain links of tracked vehicles is presented and used to examine the validity of using the static approach in the design and stress analysis of tracked vehicles. The contact forces resulting from the interaction between the track links and the vehicle components (sprocket, idler, and the rollers) as well as the interaction between the track links and the ground are evaluated using continuous force models, which are used to define generalized contact forces associated with the deformation degrees of freedom of the track links using the virtual work. The dynamic forces including the contact forces used in the finite element procedure developed in this investigation are evaluated using a 54-body vehicle model in which the track is modeled as a closed kinematic chain with 42 degrees of freedom. It is demonstrated in this study that the effect of the contact forces is more significant as compared to the effect of the rigid-body inertia forces of the chain links, and consequently, it is assumed that the deformation of the track links does not have a significant effect on the overall motion of the vehicle. In the finite element computational procedure used in this study, three-dimensional solid elements are used to discretize the links of the track chain. The numerical results presented in this investigation demonstrate that the use of the static analysis may lead to low estimates of the stresses of the track links as compared to those obtained by a dynamic stress analysis that takes into consideration the time history of the forces.