Experimental Investigation of Local Dynamics in a Bolted Lap Joint Using Digital Image Correlation

Abstract

<jats:title>Abstract</jats:title> <jats:p>The dynamics of structures with joints commonly show nonlinearity in their responses. This nonlinear behaviour can arise from the local dynamics of the contact interfaces. The nonlinear mechanisms at an interface are complicated to study due to the lack of observability within the contact interface itself. In this work, Digital Image Correlation (DIC) is used in combination with a high-speed camera to observe the local motion at the edge of the interface of a bolted lap joint. Results demonstrate that it is possible to use this technique to monitor the localised motion of an interface successfully. It is observed that the two beam parts of the studied lap joint separate when undergoing bending vibrations, and that there is a clear asymmetry in the response of the left and the right end of the interface. Profilometry indicates that the asymmetry in the response is due to the mesoscale topography of the contact interface, highlighting the importance of accounting for surface features in order to model the nonlinearities of a contact interface accurately.</jats:p>

Measurement and identification of the nonlinear dynamics of a jointed structure using full-field data, Part I: Measurement of nonlinear dynamics

“…Compared with the PT method, which tracks the motion of a single or discrete set of points, DIC can extract full-field responses [42], and is advantageous when high spatial density is required [43]. In the context of structural dynamics, DIC has already been used to study the slip and separation of jointed interfaces [44,45], and the full-field motions of small-scale and full-size engineering structures [41,46]. The focus of this article is to augment the current nonlinear dynamic test methods with fullfield measurement to improve the identification of the nonlinear properties.…”