The tensile behaviour of off-axis plant fibre composites: an insight on the non-linear stress-strain response

Shah, Darshil U. and Schubel, Peter J. and Clifford, Mike J. and Licence, Peter (2012) The tensile behaviour of off-axis plant fibre composites: an insight on the non-linear stress-strain response. Polymer Composites, 33 (9). pp. 1494-1504. ISSN 0272-8397


Composites in load-bearing applications are often exposed to off-axis loads. For plant fiber composites (PFCs) to be seriously and readily considered in structural applications, knowledge and reliable prediction of their response to off-axis loads is critical. This article (i) characterizes the stress–strain response, (ii) investigates the tensile properties, and (iii) analyses the fracture modes, of unidirectional flax-polyester composites subjected to off-axis tensile loading. A key finding of this study is that due to the nonlinear stress–strain response of PFCs, the apparent stiffness of the composite reduces by ∼30% in the strain range of 0.05 to 0.25%. In addition, through cyclic tests on the composites, the elastic strain limit is found to be only ∼0.15%. This has major implications on the strain range to be used for the determination of the composite elastic Young's modulus. Consequently, it is proposed that the tensile modulus for PFCs should be measured in the strain range of 0.025 to 0.100%. Through comparison with experimental data, conventional composite micromechanical models are found to be adequate in quantitatively describing the tensile behavior of off-axis loaded PFCs. The application of such models has also enabled the determination of, otherwise difficult to measure, material properties, such as fiber shear and transverse modulus. Off-axis loaded PFCs fail by three distinct fracture modes in three different off-axis ranges; each fracture mode produces a unique fracture surface.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 28 Mar 2017 06:58
Last Modified: 29 Mar 2017 01:15
Uncontrolled Keywords: polymer-matrix composites, off-axis loading, tensile properties, natural fibres, microfibril angle
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401602 Composite and hybrid materials
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
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