Interfacial Fracture Toughness Measurement of New Composite Material
The interface fracture toughness test of SnSb11Cu6/20steel is realized
by three-point bending experimental technique, interfacial cracks are
introduced through the overall bending of the composite panel, and the
critical energy release rate of 12.07×103 J/m2 is obtained by
calculating the energy released per unit area at the fracture interface.
To characterize the stress state of the crack tip, the stress phase
angle of the crack tip is calculated using finite element analysis(FEA).
At the same time, five sets of FEA experiments are specifically set up
to determine the magnitude of the effect of changes in the interface
fracture critical load values on the critical energy release rate. The
results show that the change in the critical load value affects the
critical energy release rate by only 0.08%. And the characterization of
the crack tip stress state reveals that the relative strength of the
shear stress that drives the interfacial cracking is weaker than that of
the positive stress after the crack propagates to a certain length under
bending conditions, which also implies that the positive stress is the
main reason that drives the interfacial crack to continue propagating
when the composite layer is completely fractured.