@inproceedings{MayrGibbsFischer2008, author = {Mayr, Andreas and Gibbs, Barry and Fischer, Heinz Martin}, title = {Spatial variation of the point mobility of a timber joist floor}, series = {DAGA 2008, Deutsche Jahrestagung f{\"u}r Akustik, Dresden.}, booktitle = {DAGA 2008, Deutsche Jahrestagung f{\"u}r Akustik, Dresden.}, year = {2008}, language = {en} } @inproceedings{MayrGibbsFischer2009, author = {Mayr, Andreas R. and Gibbs, Barry and Fischer, Heinz Martin}, title = {On force- and moment mobilities of a timber joist floor}, series = {35th German Annual Conference on Acoustics (DAGA), Rotterdam, March 2009.}, booktitle = {35th German Annual Conference on Acoustics (DAGA), Rotterdam, March 2009.}, year = {2009}, abstract = {In wood framed buildings, floors are formed by fastening wood sheathing to joists spaced at a regular interval. The sheathing is typically fastened to the joist using screws so the resulting system is a complicated periodic point-connected plate-rib structure. It is shown that the point force mobility varies significantly with position. A machine installation generally is close to discontinuities, such as at: floor edges, joist-screw locations, joints between the sheathing plates, and due to workmanship. In such cases, moment excitation might become important at some frequencies and the neglect of moments a priori can ead to inaccurate prediction of the total emission. This paper presents measured point moment mobilities with respect to the distance to discontinuities for a timber joist floor where a single layer of chipboard forms the sheathing. It is shownthat the measured point moment mobility indicates an infinite plate behaviour. This includes for positions above a joist but between screw positions. To determine the relative contribution of moments and perpendicular forces to the total structure-borne sound power, case studies of two sources, a fan unit and a whirlpool bath, are described, for various locations on a timber joist floor.}, language = {en} }