Hierarchy of the surface defects in jointed structures dynamics
Résumé
In structural dynamics, the prediction of damping remains the biggest challenge. This paper deals with the energy losses caused by micro-slip in a nominally planar interface of a structure. This paper proposes a finite element analyze and an analytical study to compute the energy dissipated by a nominally flat interface under shear loading. These numerical results are then compared to experimental result provided by an original setup which allow pure shear loading using bending vibrations of a clamped-clamped beam with innovative position of the interfaces. The objective of this test bench is to characterize the global rheology of the interface. The proposed model aims to characterize this rheology based on local settings of the interface. First, a modeling of the interface taking into account the surface defect is presented. The energy dissipated by friction in the interface is calculated during a loading cycle. This leads to a computation of the dissipated energy and thus to a nonlinear loss factor. Secondly, we propose a numerical model of the dissipated energy in the interface with different kind of rheology. Finally, we confront the results of the analytical model and the different scales of the numerical study.