Wave propagation in a wooden bar.

In this paper we will present a method to determine the material properties of a wooden bar with rectangular cross-section using guided waves in the measurement. We modelled the wood as an orthotropic material with nine independent constants. We determined the dispersion curves theoretically in the three-dimensional case using a semi-analytical finite element method.

Dynamic oscillatory behavior of a linear viscoelastic fluid bounded by an ideal linear viscoelastic membrane in torsional flow.

In rotational oscillatory rheological measurement techniques involving the plate-plate and cone-plate geometries, the interface between the measured liquid and the ambient atmosphere is sheared to the same extent as the liquid sample. In this paper, we look at the influence of a rheologically distinct lateral surface on the measured properties of the liquid and surface system when the surface is dynamically coupled to the bulk fluid. Inertia is taken into account, thus allowing for nonquasi-static velocity profiles in the massless surface film itself.

Detection of cracks at rivet holes using guided waves.

Guided Lamb waves can be used for a fast inspection of large areas, e.g. the detection of cracks at rivet holes in the fuselage of airplanes.

Measurement of the scattering of a Lamb wave by a through hole in a plate.

Flexural waves propagating in an aluminum plate containing a circular hole are studied. In the experiments the first antisymmetric Lamb wave mode A0 is excited selectively by a piezoelectric transducer. The scattered field around a circular cavity is measured pointwise using a heterodyne laser interferometer.