Community Research and Development Information Service - CORDIS

Abstract

The tensile response of continuous fibre reinforced ceramic matrix composites is not expected to show the large variation in strength properties commonly observed for monolithic ceramics. Results of recent investigations on a number of 2D reinforced CFCCs have nethertheless revealed a considerable scatter in the initial elastic modulus, in the first matrix cracking stress and in th e failure stress. One school of thought considers that the observed variability is caused by experimental factors. Elaborate testing programmes have been set up to clarify the origins of this scatter by investigation of the effect of the control mode, loading rate, specimen shape etc. Another school explains the scatter by the presence of axial stresses in the fibres and in the matrix. Although plausible, this hypothesis is difficult to verify because experimental determination of the residual stresses in every test specimen. This approach is indeed required for establishing the relationship between the magnitude of the residual stresses and the experimentally observed scatter.

At IAM a method has been developed and validated which allows to quantify the axial residue stress state in individual CFCC specimens by subjecting them to intermittent unloading-reloading cycles. The method as well as the derived relationship between residual stress state and scatter in mechanical response will be presented. .

Additional information

Authors: STEEN M, IAM, JRC-Petten (NL);FILIOU C, IAM, JRC-Petten (NL)
Bibliographic Reference: Paper presented: International gas Turbine and Aeroengine Congress and Exhibition, Stockholm (SE), 2-5th June 1998
Availability: Available from Public Relations and Publications Unit, JRC-Ispra (IT)
Record Number: 199911101 / Last updated on: 1999-08-06
Category: PUBLICATION
Original language: en
Available languages: en