This paper presents a study on active detection of internal damage based on numerical analysis of vibration dynamics in composites. Damageinduced variations of dynamic parameters are investigated both numerically and experimentally. Finite element method (FEM) is used to compute the modal parameters of composites with or without damages. Natural frequency, modal displacement, modal strain and s...

Acoustic methods of land mine detection rely on the vibrations of the top plate of the mine in response to sound. For granular soil (e.g., sand), the particle size is expected to influence the mine response. This hypothesis is studied experimentally using a plate loaded with dry sand of various sizes from hundreds of microns to a few millimeters. For low values of sand mass, the plate resonance...

Abstract Constitutive equations of finite strain elasto-plasticity are coupled to continuum damage mechanics simulate the initiation and propagation cracks in ductile materials. The diffuse deterioration material’s strength is modelled using porosity as a parameter. We show that local model yields simulation results, pathologically dependent on FEM mesh upon refinement: (i) structural behaviour...

The behavior of plain woven fabric composites is studied using three-dimensional finite elements which allows detailed modeling of the geometric complexities and spatial material variations within the fabric. Damages in the composite constituents viz. yarn and pure matrix are modeled on a continuum basis and related to their material constitutive behavior. The 3D constitutive laws describing pu...