University of Surrey

Test tubes in the lab Research in the ATI Dance Research

The strength of hybrid composites.

Pitkethly, M. J. (1987) The strength of hybrid composites. Doctoral thesis, University of Surrey (United Kingdom)..

Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (11MB) | Preview


The strength of carbon fibres in unidirectional hybrid composites of glass and carbon fibres have been investigated. It has been shown that the strength distributions of bundles of carbon fibres impregnated with resin, both unsupported and in a hybrid, may be described by the Weibull model confirming earlier reports. The primary objective of this work has been to investigate the strength and the state of dispersion of the carbon component. Hybrid composites consisting of accurately aligned arrays of bundles in two and three dimensions have been fabricated and tested. It has been shown that the strength decreases when the bundle spacing is less than a critical distance but at very low spacings the strength begins to increase again. This observation is explained with reference to the fracture behaviour and the implications for practical composites are discussed. The hybrid composites exhibit a greater strength over impregnated bundles. An hypothesis is proposed to explain this phenomena which combines thermal effects with the constraining influence of the glass and the differences in the severity of flaws in hybrid bundles. The last two arguments result in a larger critical group of failed fibres being required in the hybrid before catastrophic failure occurs. The type of hybrid specimen tested in this work enables the fracture process in the composite to be followed closely. The investigation has in principle supported the model for composite strength proposed by Batdorf, the "critical i-plet" model. However, experimental evidence indicated that a slightly different fracture process to that proposed by Batdorf was operating. The significance of this fracture process with respect to the strength and the size effect in composites is discussed.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors :
Pitkethly, M. J.
Date : 1987
Contributors :
Additional Information : Thesis (Ph.D.)--University of Surrey (United Kingdom), 1987.
Depositing User : EPrints Services
Date Deposited : 22 Jun 2018 14:25
Last Modified : 06 Nov 2018 16:53

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800