An elaboration on the shear characterization of dry woven fabrics using trellising tests

• Published in: Polymer composites Vol. 34; no. 3; pp. 359 - 367
• Main Authors: Komeili, M., Milani, A.S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-03-2013; Wiley; Blackwell Publishing Ltd
• Subjects: Applied sciences; Boundary element method; Deformation; Drying; Exact sciences and technology; Fabrics; Forms of application and semi-finished materials; Laminates; Mathematical analysis; Nonuniform; Polymer industry, paints, wood; Shear; Stiffness; Technology of polymers; Laminate; Biaxial stress; Propylene polymer; Mechanical properties; Shear strength; Tensile property; Experimental study; Mineral fiber; Composite material; Manufacturing process; Glass fiber fabric; Olefin polymer; Measurement method; Woven material; Draping
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.22347

Material characterization of woven fabric composites in dry form is one of the most crucial steps prior to the design and optimization of composite manufacturing processes. High stiffness of yarns under axial tension and low stiffness under in‐plane shear makes the latter the dominant deformation mode during draping of woven fabrics. Bias‐extension (BE) and shear frame (SF) tests are two widely used experimental setups for the characterization of woven fabrics under the shear (also called trellising) mode. This article outlines two general approaches for the characterization and normalization of data collected from the above standard tests. The first approach is based on the total energy absorbed by the fabric specimen along with the total work induced by the external force on the moving head of the tensile test machine. The second approach uses a variational formulation along with the principle of virtual work. Using both approaches, it is shown how, in the BE test, an auxiliary specimen with a different aspect ratio can be used to cope with the problem of nonuniform deformation (formation of three different shear regions) in the specimens. To illustrate the application of both methods, they are applied to predict in‐plane shear stiffness of a glass/PP plain weave under SF and BE tests. It is suggested that the shear stress can be used as a normalized parameter to compare data from different trellising tests. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers