The Brake-Reuß Beams: A System Designed for the Measurements and Modeling of Variability and Repeatability of Jointed Structures with Frictional Interfaces

Abstract

The Brake-Reuß beams were originally proposed as a system for study by the Nonlinear Mechanics and Dynamics (NOMAD) Research Institute in order to assess several hypotheses governing the role of variability and repeatability in systems with jointed interfaces. The Brake-Reuß beams consist of three related systems: a monolithic beam, a monolithic beam with three interfaces, and a jointed beam with three bolted joints. Preliminary measurements of the frequency response functions (FRFs) of the three systems have been made in order to quantify the effect of the bolted interfaces. The preliminary results indicate that for the systems studied, one class of modes (the bending modes) are sensitive to the residual stresses in the system (as correlated to the order in which the bolts are tightened), and a second class of modes (the torsional modes) are so sensitive to the interfacial conditions that the effect due to the residual stresses is not distinguishable from other effects.