The Wave Finite Element Method applied to a one-dimensional linear elastodynamic problem with unilateral constraints

Carlos Yoong (1) , Anders Thorin (1) , Mathias Legrand (1)

1 Structural Dynamics and Vibration Laboratory [Montréal]

The Wave Finite Element Method (WFEM) is implemented to accurately capture traveling waves propagating at a finite speed within a bouncing rod system and induced by unilateral contact collisions with a rigid foundation; friction is not accounted for. As opposed to the traditional Finite Element Method (FEM) within a time-stepping framework, potential discontinuous deformation, stress and velocity wave fronts are accurately described, which is critical for the problem of interest. A one-dimensional benchmark with an analytical solution is investigated. The WFEM is compared to two time-stepping solution methods formulated on a FEM semi-discretization in space: (1) an explicit technique involving Lagrange multipliers and (2) a non-smooth approach implemented in the Siconos package. Attention is paid to the Gibb's phenomenon generated during and after contact occurrences together with the time evolution of the total energy of the system. It is numerically found that the WFEM outperforms the FEM and Siconos solution methods because it does not induce any spurious oscillations or dispersion and diffusion of the shock wave. Furthermore, energy is not dissipated over time. More importantly, the WFEM does not require any impact law to close the system of governing equations.

Mots clés: Wave Finite Element Method; unilateral contact mechanics; shock waves; elastic wave propagation; nonsmooth dynamics

Domaines: Vibrations [physics.class-ph]; Mécanique des structures [physics.class-ph]

Carlos Yoong, Anders Thorin, Mathias Legrand. The Wave Finite Element Method applied to a one-dimensional linear elastodynamic problem with unilateral constraints. The ASME 2015 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Aug 2015, Boston, United States. ⟨10.1115/DETC2015-46919⟩. ⟨hal-01194922⟩