Determination of mechanical properties of parallelepiped materials embedded in solid medium and deformed under confining pressure

Most hydrostatic pressure deformation techniques necessitate the use of a confining medium to apply the pressure. In the case of solid confinement, the embedding medium may modify the specimen stress tensor hydrostaticity. In this study, parallelepiped specimens deformed under gaseous confining pressure with the Paterson press, are embedded in cylindrical jackets. Finite element modelling shows that the pressurization of the ‘sample + jacket’ assembly generates a pre-compression stress of the sample before any deformation test. The evolution of the pre-compression stresses with the sample and jacket Young's moduli ratio, the sample and jacket yield stresses ratio and the spacing between sample and jacket, are characterized. This modelling is applied to 4H-SiC deformed in the brittle regime with the Paterson press as an example.