Authors: Sweety Kumari S Nithya N Padmavathi N Eswara Prasad J Subrahmanyam
Publish Date: 2010/01/01
Volume: 45, Issue: 1, Pages: 192-200
Abstract
Monotonic tensile properties and fracture behaviour of carbon fibre filament materials namely single/mono and multifilaments two and four filaments as well as virgin carbon tows have been evaluated and discussed Micro composite or single fibre approach is used in this study which facilitated the evaluation of tensile properties and nature of fracture of carbon filament materials in a relatively short time with a large number of inexpensive trials Tensile tests have been conducted on these filament materials at ambient temperature and laboratory air atmosphere Load–elongation and the corresponding stress–strain plots thus obtained have been analysed to understand the tensile behaviour The peak tensile strength of single carbon filament is found to be 38 GPa and the value of the resilience obtained is 19 MJ/m3 The peak tensile strength was found to increase moderately with further increase in number of filaments However the value of resilience was found to increase with increase in the number of fibres which is attributed to the controlled failure of multifilaments On the other hand the tensile strength of virgin carbon tow without matrix was found to be 113 GPa and the value of the fracture energy was determined to be 99 MJ/m3 which is nearly one fourth or even less than the corresponding values of the mono and multifilaments The data obtained in the case of the virgin carbon tows were further analysed to evaluate the Weibull statistical parametersThe authors are indebted to Dr AM Srirama Murty and Dr G Malakondaiah former and present Directors respectively Defence Metallurgical Research Laboratory DMRL for their constant encouragement and kind permission to publish this article The authors express their grateful thanks to Dr M Srinivas and Dr Vikas Kumar of DMRL for many useful suggestions The authors are also grateful to Smt G Rohini Devi Scientist Advanced Systems Laboratory Hyderabad for the provision of the facilities to conduct some of the experiments for this study Funding from DRDO is gratefully acknowledged
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