Upright Piano Action: Experimental Characterization and Multibody Modeling

In this work, a multibody model of an upright piano action is presented, that has been experimentally validated via high speed camera. The model takes all the bodies into account as well as specific felt force laws and body geometries to deal with intermittent contacts. In addition, experimental tunings of model parameters have been undertaken. Simulations of the model allow, among others, to estimate the maximal playing frequency and a minimal input force on the key to produce a sound. More specifically, the bridle strap and butt spring usefulness are discussed, showing the interest of the multibody modeling approach for studying piano actions