<p>A common engineering issue that affects many industries is that structures that contain screws and bolts can loosen which in turn can lead to failure. This loosening of the fasteners can happen from two different scenarios. The first being sustained vibrations during a long period of time leads to a slower loosening while the second being shock excitation where the fastener can loosen in less than a second. Currently the models for loosening in joints are done using very high-fidelity finite elements or through high level analytical equations. These methods &nbsp;can be very successful for a singular fastener. However, these methods are too computationally heavy to simulate the loosening in more than one joint. Since this is the case there is not much information on how these joints interact with one another as loosening takes place. This work uses a new reduced-order model (ROMs) that was derived from an experimental study of a split-Hopkinson pressure bar for loosening from shock excitation. This ROM in combination with finite element models to create a split-Hopkinson pressure bar where there are three bars and two joints. Then to take this a step further in an effort to lower computational cost the spectral element method (SEM) is utilized to replicate data from the FEA model. These models give way to show the interactions from the joints as they loosen.</p>

Dynamic Wave Interactions in Axial Rods With Multiple Threaded Interfaces

Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2021/volume/85369

ASME 2021 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE2021)

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