Cam-based passive variable friction device for structural control

Downey, Austin
Theisen, Connor
Murphy, Heather
Anastasi, Nicholas
Laflamme, Simon
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A solution to increasing the resiliency of civil structures with respect to natural and man-made hazards is the implementation of supplemental damping systems. These systems can be constructed using passive, active, and semi-active devices. In particular, passive devices are widely accepted in the field of structural engineering, because they do not require power to operate and can be holistically integrated into the structural design process. This paper investigates the use of 3D printing technology to expand on the possibilities in passive damping, notably in the fabrication of a variable friction device. This device uses a 3D printed cam with a pre-defined surface profile to vary the normal forces applied to a traditional sliding plate friction system. It follows that these varying forces develop a variable damping force that is dependent on the device’s displacement. In this work, a friction model is developed to characterize the device’s behavior. This model is then validated on various cam profiles by exposing the device to a set of harmonic motions and to a nonstationary motion. Results show a high level of agreement between the experimental results and analytical model.


This is a manuscript of an article published as Downey, Austin, Connor Theisen, Heather Murphy, Nicholas Anastasi, and Simon Laflamme. "Cam-based passive variable friction device for structural control." Engineering Structures 188 (2019): 430-439. DOI: 10.1016/j.engstruct.2019.03.032. Posted with permission.

Variable friction, Passive device, Structural control, Vibration mitigation, Supplemental damping, Displacement control, 3D printing