Thin inclusion reinforcement (stiffener)

Summary

The presence of a second phase in a matrix material leads to inhomogeneity in the mechanical fields. The theoretical solution of a zero-thickness, infinitely rigid line inclusion embedded in an elastic material has the following features:

  • similarly to a fracture, a square-root singularity in the stress/strain fields is present at the tip of the inclusion;
  • in a homogeneous matrix subject to uniform stress at infinity, such singularity only arises when a normal stress acts parallel or orthogonal to the inclusion line, while a stiffener parallel to a simple shear does not disturb the ambient field.

We have confirmed these characteristics through photoelastic transmission experiments.

Related papers:

  • Noselli, G., Dal Corso, F. and Bigoni, D. (2010).
    The stress intensity near a stiffener disclosed by photoelasticity.
    International Journal of Fracture, 166 (1-2), 91-103.
  • Dal Corso, F. and Bigoni, D. (2009).
    The interactions between shear bands and rigid lamellar inclusions in a ductile metal matrix.
    Proceedings of the Royal Society A, 465 (2101), 143-163.
  • Dal Corso, F., Bigoni, D. and Gei, M. (2008).
    The stress concentration near a rigid line inclusion in a prestressed, elastic material. Part I. Full field solution and asymptotics.
    Journal of the Mechanics and Physics of Solids, 56 (3), 815-838.
  • Bigoni, D., Dal Corso, F. and Gei, M. (2008).
    The stress concentration near a rigid line inclusion in a prestressed, elastic material. Part II. Implications on shear band nucleation, growth and energy release rate.
    Journal of the Mechanics and Physics of Solids, 56 (3), 839-857.