Abstract

Structural assemblages, found in automotive, civil and aerospace applications, exhibit nonlinearities due to contact and friction occurring at joint interfaces. For instance, damping is heavily affected by the contact state and evolution during motion and depends on the vibration amplitude and shape. Moreover, system parameters as macroscopic manufacturing imperfections, bold preloads, and material properties play a major role in affecting the structural behaviour.

Surrogate models of whole joints have been employed in structural dynamics for decades. While offering a compact, overall description of the joint behaviour, they heavily rely on calibration for expensive experimental campaigns. Therefore, they are not accurate outside their calibration window. Moreover, the detailed interface state (contact stresses, local opening/closing, slipping/sticking regions, etc) cannot be retrieved.

At the other end of the spectrum, high-fidelity finite element models can deliver very accurate representation of the dynamic contact state at the interfaces. Unfortunately, such models are computationally extremely expensive and cannot be used for design and monitoring.

Reduced order models can provide, in principle, fast versions of high-fidelity models when the solution is assumed to live on a manifold, either flat or curved. However, the construction of such manifold and the efficient treatment of nonlinearities are nontrivial tasks for jointed structures.

In this talk, we review the state of the art of reduced order models for joints, and present some recent work performed in our group. We conclude by giving some perspective on industrial needs and research directions.