Influence of Off-Axis Tensile Loading on Single Fibers Properties
In single fiber experimentation, it is generally expected that the samples align closely along the axis of testing, but it is unclear how dramatically an initially off-axis sample would affect the final tensile stress and strain results. It has been previously demonstrated by this group that a unique loading stage, referred to as the nano-testing stage or “nTS,” can be used in conjunction with a digital optical microscope to view and test fiber samples. The nTS, designed and developed by Psylotech, Inc., features a lateral positioning actuator intended for specimen alignment in the direction of loading, but in this study, it is instead used for deliberate off-axis alignment of a single fiber sample prior to testing. Classes of fibers including PPG Industries E-fiberglass, Hexcel carbon fiber AS4, and Dyneema UHMWPE SK76 are tested in ideal alignment and at an off-axis distance of 0.25 mm to 0.50 mm, which produces an approximate angle of 2.87 to 5.74 degrees with the testing axis. Stress and strain data from these off-axis experiments are then compared to the measurements acquired via the on-axis experiments to determine misalignment effects, if any. Precise details regarding the testing procedures and the results are provided in the paper.
Authors: Vincent Wu, and Paul Moy
Conference: SAMPE Seattle 2017