One exciting outcome of the tendons/rockbolts project is that there are some high frequency modes in embedded bars which travel with relatively low radiation of energy into the surrounding medium, and therefore suffer relatively little attenuation. However it turns out that the propagation of these modes is strongly affected by any curvature of the bar. Currently there is no analytical basis for studying the propagation in curved bars, although propagation in straight bars is very well understood (this can be modelled using the group's existing Disperse software). This project aims to develop a mathematical model for waves in curved bars and curved plates. In parallel, validation of the model is being performed using experiments and Finite Element simulations.

Example of simulated wave propagation

References

D Gridin, R V Craster, J Fong, M J S Lowe, M Beard, "The high-frequency asymptotic analysis of guided waves in a circular elastic annulus", Wave Motion, vol 38, pp. 67-90, 2003.

A Demma, P Cawley, M J S Lowe, B Pavlakovic, "The effect of bends on the propagation of guided waves in pipes", ASME J. Press Vess. Technol., vol 127, pp.328-335, 2005.

J Fong, M J S Lowe, "Leaky quasi-modes in curved plates", Review of Progress in Quantitative NDE, eds. D.O. Thompson and D.E. Chimenti, American Institute of Physics, New York, vol. 24, pp. 180-187, 2005.