%0 Journal Article %A Taazount, Mustapha %A Pluquin, C. %A Renard, J. %A Bouazzouni, A. %D 2008 %I Begell House %N 2 %P 123-140 %R 10.1615/IntJMultCompEng.v6.i2.20 %T Dynamic Identification of Junction Forces by Discrete Time Identification Methods %U https://www.dl.begellhouse.com/journals/61fd1b191cf7e96f,1283026f051f4626,2f08221a6a6b4a57.html %V 6 %X Substructuring techniques consist of dividing a large problem into subparts to simplify their analysis. In engineering dynamics, substructuring techniques are primordial to solving large numerical systems and perform experimental analyses on large structures. In this work, we look at a novel technique for identifying the dynamic junction forces induced in mechanical superstructures by dynamic ground movements. The proposed method will be applied to civil engineering (building) as well as industrial mechanical (vehicles) structures. For the latter case of structures, we define the system as composed of three parts: the cockpit, the suspension system, and the ground connection. The ground-structure coupling part is the part of concern in this article. Under the action of external forces, the resulting behavior of dynamic ground-structure coupling is nonlinear. Apprehending behavior of this type is not an easy matter. To overcome the difficulty in identifying the junction forces applied to the cockpit substructure, we propose considering the structure as a "black box" dynamic state system. The proposed method for identifying junction forces may be globally subdivided into two steps: identification of forces from acceleration data fields and discrete identification with stable and physically realizable dynamic systems. It is based on numerical developments and experimental validations. This approach calls upon the techniques of substructuring and discrete time dynamic identification. Here the method of substructuring is based on the concept of dynamic impedances and the mechanical action-reaction principle. The method for identification is based on the technique of the autoregressive processes with X exogenous excitation "ARX" in multiinput single-output "MISO" and multioutput multiinput "MIMO" cases, and based on the exponential continuous-discrete time transformation technique. The ABC dynamic state system is carried out. It shows that the dynamic state depends only on stable poles of the AR part of the identified ARX signals. Applications were carried out on academic examples of structures and real industrial vehicles. The results obtained allow the validity of the step and show the effectiveness of the identification by ARX in MISO and MIMO cases, with interface reaction forces defined according to external accelerations of the connection interfaces. %8 2008-06-21