An Experimental Investigation of Axial Cutting Under a Tension Deformation Mode 2020-01-0206
The most common use of tension energy absorption is found in personal fall arrest systems, however, there exist a plethora of possible applications in the automotive field for both vehicular and roadside safety hardware. During a fall, cables attached to a safety harness must not exceed a maximum arresting force over an arresting extension. The main disadvantage of the current state of the art for fall arrest is that energy dissipation is a result of tearing and failure of fabric materials which causes erratic and fluctuating loads. Axial cutting; a novel energy dissipation mechanism developed by researchers at the University of Windsor, has been shown to minimize load fluctuations while maintaining a stable load. Its capabilities have been explored in compression, but no studies have been conducted in tension. A set of test specimens were chosen for this purpose based on predictions from analytical models. These specimens were circular extrusions made from AA6061 in both T4 and T6 temper conditions. They varied in diameter from 50.8 to 63.5mm, and varied in thickness from 1.25, 1.59 and 3.18mm. The tests were performed quasi-statically using a custom long stroke tension/compression machine designed and engineered at the University of Windsor with a maximum load capacity of 300kN. Fixtures were created so that the machine would be able to carry out axial cutting in tension. Strain-gauge based load cells and non-contact displacement transducers were used to observe the load and displacement response of the set-up. The results showed that specimens that were axially cut in tension had very high tensile force efficiencies in the vicinity of 90% and in turn very low fluctuations in loads. In addition, the loads that resulted presented high repeatability and predictability from analytical models.
Anthony Gudisey, William Altenhof, John Magliaro