Decoupling of mechanical systems : the link-preserving, decoupling method
Faculty of Applied Engineering Sciences
Heverlee :Katholieke Universiteit Leuven, Departement Werktuigkunde, 2014
Engineering sciences. Technology
International Conference on Noise and Vibration Engineering (ISMA), September 15-17, 2014, Leuven, Belgium
University of Antwerp
Mechanical systems are frequently a composition of substructures, connected by means of links. The substructures can be categorized in two groups: the sources and the receivers. Energy reaches the receivers through several connection points or links. In order to estimate the contribution of a certain force to the overall vibrational level at a specific receiver location, it is required to investigate the decoupled system's frequency response functions (FRFs). The conventional way to find these functions is the so-called transfer path analysis (TPA) technique. In such analysis it is necessary to decouple the sources relative to the receivers. In our contribution it will be proven that the decoupling of a mechanical system can also be performed mathematically, causing some major advantages. First, the entire system remains unchanged providing the real nonlinear boundary conditions, since the substructures maintain their natural force interactions. This is important as a structure can only be considered linear in the neighborhood of its working point. Any significant deviation such as the removal of a car's engine, leads to erroneous results. Secondly, the time to physically demount and remount the structure vanishes which leads to a gain in time, resulting in practical as well as financial advantages. The new method is called the Link-Preserving, Decoupling Method (LPD-method) since the links between the substructures remain unchanged while the decoupling is obtained from mathematical considerations. In order to prove the validity of the suggested method, simulations are performed on a simplified finite element (FE) model of a vehicle chassis.