Identification, using nanoindentation tests, of mechanical behaviour of a 2C22 steel presenting a residual stress state

The effect of microscale residual stress from thermal cooldown on the nanoindentation properties of fibre-reinforced composites

“…The use of full 3D modelling allows the effects of both equibiaxial and non-equibiaxial stress states to be determined. 22 The bulk 6376 epoxy has been modelled as a 400 Â 400 Â 200 m 3D deformable solid in order to ensure that far-field boundary effects on the indentation were negligible. A single plane of symmetry has been applied to the mid-plane of the nanoindentation substrate under the point of the Berkovich indentation, as shown in Figure 4.…”

“…The sensitivity of nanoindentation properties to the magnitude and nature of such residual stresses has previously been successfully investigated through the use nanoindentation experiments and modelling on aerospace aluminium alloys, 20,21 steel 22 and thinfilm materials. [23][24][25][26][27] While the vast majority of these investigations assume an equibiaxial stress state and use an asymmetric modelling approach, Breuils et al 22 carried out full three-dimensional (3D) finite element simulations, allowing the effects of non-equibiaxial stress states to be determined. In these material systems, the material properties measured using the nanoindentation technique are dependent on the nature and magnitude of the residual stress-state in the substrate, with compressive stresses generally leading to an increase in the calculated properties, and a decrease in properties observed for cases where tensile residual stresses were present.…”