Some Problems Arising During the Experimental Characterization of Compliant Knitted Mesh

The present paper discusses about technical issues that may arise during field physical measurements on compliant knitted mesh. The experimental tests are performed with a custom bi-axial electro-mechanical equipment. A particular arrangement, composed of flexible wires, is adopted to reduce undesired boundary effects, these last being unavoidable also with a stiff clamping system. The periodic geometry pattern of the nets play a positive role for the application of a two-dimensional frequency analysis, both for the unloaded and loaded cases. One of the objectives of the present work is to propose an image-based technique to evaluate how local disturbances vanish within the net. The image processing measurement system is also useful to investigate the strain differences in the regions close to the specimen borders; to this specific aim, the whole measured image of the net was split into different regions by means of a topology approach, similar to the finite element discretization.