Buckling of a thin rod under cylindrical constraint
Jay Miller (MIT), Tianxiang Su (Harvard), Katia Bertoldi (Harvard University), Pedro Reis (MIT)
Engineering Mechanics and Materials in the Oilfield
Tue 2:40 - 4:00
Sayles 105
We investigate the buckling and post-buckling behavior of a thin elastic rod, under cylindrical constraint, with distributed loading. Our precision model experiments consist of injecting a custom-fabricated rod into a transparent glass pipe. Under imposed velocity (leading to frictional axial loading), a portion of the initially straight rod first buckles into a sinusoidal mode and eventually undergoes a secondary instability into a helical configuration. The buckling and post-buckling behavior is found to be highly dependent on the system's geometry, namely the injected rod length and the aspect ratio of the rod to pipe diameter, as well as material parameters. We quantify the critical loads for this sequence of instabilities, contrast our results with numerical experiments and rationalize the observed behavior through scaling arguments.