Publications Details
The effect of the contact model on impact-vibration response
Impact is a phenomenon that is ubiquitous in mechanical design; however, the modeling of impacts in complex systems is often a simplified, imprecise process. In high fidelity finite element simulations, the number of elements required to accurately model the constitutive properties of an impact event is impractical. Consequently, rigid body dynamics with approximate representations of the impact dynamics are commonly used. These approximations can include a constant coefficient of restitution, penalty stiffness, or single degree of freedom constitutive model for the impact dynamics that is specific to the type of materials involved (elastic-plastic, viscoelastic, etc.). In order to understand the effect of the impact model on the system's dynamics, simulations investigate single degree of freedom and two degrees of freedom systems with rigid stops limiting the amplitude of vibration. Five contact models are considered: a coefficient of restitution, penalty stiffness, two similar elastic-plastic constitutive models, and a dissimilar elastic-plastic constitutive model. Frequency sweeps show that simplified contact models can lead to incorrect assessments of the system's dynamics and stability, which can significantly affect the prediction of wear and damage in the system.