The Tangential Contact Stiffness: A Static or Dynamic Property? by Alfredo Fantetti, Oct. 11, 2022

Tangential Contact Stiffness

Alfredo_Fantetti

Imperial College London

October 11, 2022

Abstract:

The tangential contact stiffness is an important parameter used as input in contact models for the nonlinear dynamic analysis of jointed structures. It can strongly affect the prediction of resonance frequencies and vibration amplitudes. Analytical and numerical techniques are available for contact stiffness estimations, but their reliability remains unknown due to a lack of validation data from the contact interfaces during vibration. This talk will present measurements from different experimental techniques, including hysteresis measurements, dynamic substructuring and ultrasound to provide novel insights into the physics of this parameter. Experimental data are then used to upgrade existing simulation tools such as boundary element solvers that take as input real interface topographies. Based on the presented experiment and simulations, guidelines are eventually provided on how to best include the contact stiffness in contact models for a more accurate nonlinear dynamic analysis of jointed structures.

Biography:

Alfredo Fantetti is a Research Associate in the Dynamics Group (Mech. Eng. Dept.) at Imperial College London. In 2017, Alfredo graduated in Mechanical Engineering at Politecnico di Torino and started a Marie Curie-funded PhD at Imperial College London. His PhD addressed the experimental characterization of frictional hysteresis for the nonlinear dynamic analysis of jointed structures. His post-doc focuses on the experimental and numerical analysis of the dynamic performance of underplatform dampers used in aero-engine turbine blades. In 2021, Alfredo was awarded the "Innovation in Tribology Award" by the Institute of Physics for his innovative research in the field of tribology. In 2020, he won the "Young Stress Analyst competition" awarded by the British Society for Strain Measurement to recognise excellence in early career research, for his research on ultrasound. In 2017, he was awarded the "DeMichele scholarship" as a promising young researcher at the IMAC conference for his master thesis work. Alfredo is planning to pursue an academic career and has applied for individual research fellowships to develop a new experimental technique for friction characterization in vibrating structures.