| In this investigation, a computer aided analysis procedure is developed for the dynamics and stress analysis of large-scale tracked vehicles that consist of rigid and flexible components. The track is considered as a closed kinematic chain that consists of track links connected by revolute joints. The contacts between the track links and the rollers, track links and the sprocket and the idler and track links and ground are represented by nonlinear continuous force models. The equations of motion of the tracked vehicle are formulated using the Lagrangian approach and nonlinear constraint equations that describe mechanical joints and specified motion trajectories in the system are adjoined in the system differential equations using the technique of Lagrange multipliers. The mixed system of differential and algebraic equations are solved using a direct numerical integration method coupled with a Newton-Raphson algorithm to check on the violations in the kinematic constraints. The dynamic forces acting on the track links including the contact forces are evaluated and used to study the deformations and stresses of the track links using the finite element method. The numerical results obtained demonstrated 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 dynamic stress analysis that takes into consideration the time history of the forces.; A design methodology which integrates the multibody technique, the finite element method, and experimental modal analysis techniques is also proposed in this investigation. In this methodology, a prototype can be built using the results obtained by using multibody techniques and the finite element method. The vibration modal parameters of the prototype can be obtained experimentally and used with general purpose multibody computer programs to evaluate the performance of the proposed design. The finite element description can then be adjusted in order to obtain more realistic model that compares well with experimental data. Using the more realistic finite element model, design modifications can be made in order to improve the performance of the design model. |
