Stress intensity factors for internal surface cracks in autofrettaged functionally graded thick cylinders using weight function method

•Residual stresses significantly decreases as graded ratio of FGM is increased.•Brittle particles considerably reduce the SIFs under applied pressure.•Autofrettage of cracked FGM cylinders improves their pressure capacity.

Stress intensity factors for internal surface cracks in autofrettaged functionally graded cylinders have been studied. It is assumed that the mechanical properties change with a power law in radial direction of cylinder. Effects of autofrettage pressure, volume fraction, crack dimensions and cylinder thickness on the stress intensity factors in deepest and surface points of cracks were determined by using the weight function method. Results show that the changes in volume fractions of ingredients have more effects than the other parameters.