COMPUTER-AIDED NOISE-CONTROL

The present paper is intended to broaden existing knowledge of noise research by indicating the capabilities and potentials of computer aided noise control, using orthopaedic surgical instruments as an example. A sound field is adequately described if the alternating pressure p and the velocity v in all three spatial axis are known for each point in the sound field at any time. In the first phase, the mechanical behaviour of the structure (structure borne sound) is determined using the finite element method. Structure borne sound is linked to airborne sound via primary radiators with the geometric shape of the finite elements, the methods used are called Rayleigh-Method and Direkt Finite Element Method by Hubner. The calculation program provides sound pressure, sound particle velocity and the sound intensity at the points of the ISO standard hemisphere together with the radiated sound power. A comparison with experimentally-determined level confirms satisfactory simulation quality.