Intraply shear

Surface shear angles and material draw-in have been optically measured by the use of a camera. The intraply shearing effects can be measured by the in-plane shear angle and seems to be the most important deformation mode of textile composite. 

Lebrun G, Bureau MN, Denault J. Evaluation of bias-extension and picture-frame test methods for the measurement of intraply shear properties of PP/glass commingled fabrics. Compos Stmct 2003 61 341-52. 

Inter-fiber (intraply) shear occurs when the fibers rotate about the stitches or weave centers. 

When the textile fabric reinforcement is combined with the matrix to form the composite prepregs, a set of deformation modes are introduced, which may be referred to as top-level deformation modes since they involve the movements of the reinforcement (macro- and micro-level fabric deformation mechanisms) and the matrix. They are in fact the conformation modes of the composite prepreg sheet or group of sheets, as is usually the case, during the forming process. The hierarchy of the top-level deformation modes consist of transverse flow, resin percolation, interply shear and intraply shear, as summarized by Cogswell and revisited by Martin et... 

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