Paper Title:

Experimental Characterisation of Parameters Controlling the Compressive Failure of Pultruded Unidirectional Carbon Fibre Composites

Periodical Applied Mechanics and Materials (Volumes 24 - 25)
Main Theme Advances in Experimental Mechanics VII
Edited by R.A.W. Mines and J.M. Dulieu-Barton
Pages 15-22
DOI 10.4028/
Citation Ole Thybo Thomsen et al., 2010, Applied Mechanics and Materials, 24-25, 15
Online since June 2010
Authors Ole Thybo Thomsen, K.K. Kratmann
Keywords Compressive Failure, Digital Image Correlation (DIV), Fourier Transform Misalignment Analysis (FTMA), Kinkband Formation Models, Modified Iosipescu Test, Pultrusion, UD CFRP
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The classical kink-band formation models predict that the compressive strength of UD carbon fibre reinforced composite materials (UD CFRP) is governed by fibre misalignment as well as of the mechanical shear properties. A new image analysis procedure for experimental determination of the fibre misalignment, the Fourier transform misalignment analysis (FTMA), has been developed. Moreover, a modified asymmetric Iosipescu test specimen geometry has been developed and validated for accurate measurement of the composite material shear properties without parasitic effects due to axial splitting. In the test procedure the shear strain distribution is measured using Digital Image Correlation (DIC) and the results calibrated based on FEA modelling results. Using the measured properties as input, the predictions of the classic compressive strength models have been compared with measured compressive strengths. Finally, an alternative approach to the classical kink band equilibrium has been proposed and demonstrated to provide more accurate predictions than the classical models.