Biaxial testing of continuous fibre reinforced aluminium tubes

摘要

Composite tubes of aluminium and aluminium alloy containing hoop wound alumina (Altex) fibreswere fabricated using a liquid metal infiltration method. The tubes were well consolidated, with lowporosity, and good bonding between fibre and matrix, as confirmed using 'rule of mixtures'calculations of elastic modulus. Mechanical properties were evaluated in the principal directions ofthe tube under uniaxial and biaxial stress loading conditions, and damage modes were studied. Stressquarter diagrams were constructed on the basis of a maximum stress failure mechanism, and failureenvelopes were produced using the measured values of yield stress and failure strength. Thecomposition and condition of the matrix was shown to influence the shape of the failure envelope and,in turn, the mode of failure of the tube for a given biaxial stress ratio. Good correlation was obtainedbetween predictions made from the stress quarter diagrams and the fracture paths observed in testedtubes.