Nonlinearity detection and dynamic characterisation of aramid and silicon carbide fibres

摘要

The deployment of fibres made of high performance materials such as aramid polymers is spreading in many different engineering applications. Thanks to their excellent mechanical properties, they are being applied also in the structural field. The question that prompted this study is whether nonlinearity can be used for assessing structural damage in aramid fibres. The idea was to detect weak nonlinearities in the dynamic response measured on fibres and ropes, and to look for correlations with damaged samples of the material. Positive results would usher the possibility of using such quantity, as an indicator for evaluating the residual life span of aramid elements, cables and ropes. In order to investigate the sensitivity of this approach, nonlinear characterisation tests were carried out on aramid fibres by applying sweep-sine excitations at different loading levels. In order to have a comparison term and to test the setup machine, a similar characterisation procedure was also applied to fibres made with a different high performance material: silicon carbide.