42. An Assessment of the Applicability and Epistemic Uncertainties Inherent to Different Classes of Friction Models for Modeling Bolted Interfaces

Modeling the contact in bolted structures is a persisting challenge in the community. One of the greatest obstacles in developing predictive models is a lack of understanding of the relative epistemic uncertainties (model form errors) inherent to different choices of contact constitutive modeling approaches. The contact constitutive models affect the stiffness and hysteresis of the contact resulting in different frequency and damping properties. Multi-Objective Optimization (MOO) is applied to find solutions that minimize the deviation in both frequency and damping from experimentally measured properties. Then the concept of non-domination of design parameter sets is used from MOO approaches to develop a quantitative understanding of the epistemic uncertainties, i.e., the inexactness of each approach to represent experimentally measured properties. The current study investigates the uncertainty associated with conventionally popular simplified approaches such as the use of phenomenological models (e.g., Iwan or Bouc-Wen models) and constitutive models (e.g., Jenkins models) within a whole-jointed framework.