Non-frictional jamming of inclusions - an ignored toughening effect
The load carried by inclined platelets bridging a crack is approximately calculated in the absence of bonding and friction in order to separate the effect of non-frictional jamming from that of frictional load transfer. This is done by means of a simple model where the strain field is essentially reduced to uniaxial compression of certain matrix regions. The work of opening the crack against the jamming force provides a contribution to the fracture toughness of the composite. The estimate shows that this contribution may be of practical interest for ceramics.