15th European Conference on Composite Materials pages:1-8
European Conference on Composite Materials
European Conference on Composite Materials edition:15 location:Venice, Italy date:24-28 June 2012
In order to characterize bamboo (Guadua angustifolia) fibres mechanically, single fibre (SFT), dry fibre bundle (DFB) and impregnated bundle (IFB) tests were performed. It was found that the strength of the fibres follows a Weibull distribution, furthermore showing that the variability of the material (obtained from the shape parameter m=8.3) is relatively low. The tensile strength of the fibres was around 800 MPa (SFT). In order to determine experimentally the two Weibull parameters from load-strain (P-ε) curves in the DFB, it was found that the alignment of the fibres and therefore the uniform tensile loading of the fibres is a critical aspect in order to obtain consistent results. For this, a methodology including techniques to evenly spread the fibres in a UD configuration and strain measurements with an optical extensometer, were developed. For the DFB configuration the tensile strength of the bamboo fibres dropped 20% in comparison with the SFT and the Weibull shape parameter reduced to 5.3, indicating higher variability. In the case of the IFB, the characteristic tensile strength (σo=254 MPa) was found 14% higher than the results from standard UD bamboo fibre/epoxy composites previously reported. The results allow formulating guidelines regarding methodology and practical feasibility of the different tensile tests (i.e. maximizing reliability with minimal preparation time and amount of material) in order to characterize not only bamboo fibres but also, other natural fibres.