Model-Based prediction of linearized stiffness and damping values for bolted joints

Forschung im Ingenieurwesen, vol. 89

Abstract

Abstract The virtual testing of a technical product in terms of its acoustic behavior enables the engineer to evaluate the design without the need for physical prototypes. To predict the acoustic behavior virtually, models should consider both the dynamic excitations of the system and the transfer behavior of sound from the excitation source to the user. The transfer behavior is influenced by the resonance frequencies and the damping of the structure, the latter of which mainly occurs in the joints between the components. Stiffness and damping values are required to design the transfer behavior of the joints. For this, load conditions must be determined. To model load and displacement states occurring in the joint in dynamic applications, a distributed approach can be used by modelling in the FEM. This makes it possible to consider the influence of the microgeometry in the form of the surface roughness on the transfer behavior of the joint. To use the continuously distributed load and displacement states in concentrated model elements or as design parameters in the form of linearized stiffness and damping values, the load conditions must be linearized in the considered operating point. This paper therefore presents a method for the model-based derivation of linearized stiffness and damping values, which assesses the influence of the design of the joint on stiffness and damping on the basis of experimentally determined surface roughness. For this, distributed models in the FE are parameterized based on a measured surface roughnesses. Based on these models, linearized stiffness and damping values are determined for different joint geometries. This makes it possible for the first time to derive model-based linearized stiffness and damping values for different joint geometries. The Brake-Reuss beam is used as an academic object of investigation. Transferring the method to industrial systems can optimize costs and resources in the product development process.

Authors 4

1. Rasim Dalkiz corresponding Aachen Institute for Machine Elements and Systems Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

2. Georg Jacobs Aachen Institute for Machine Elements and Systems Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

3. Gregor Höpfner Aachen Institute for Machine Elements and Systems Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

4. Stefan Wischmann Aachen Institute for Machine Elements and Systems Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany

   Institute for Machine Elements and Systems Engineering, RWTH Aachen University, Schinkelstr. 10, 52062, Aachen, Germany