Interfacial transient thermal fracture of adhesively bonded dissimilar materials

The effect of a transient thermal load on an interface crack in adhesively bonded dissimilar materials was experimentally studied by using photothermoelasticity. It is determined that the effect of the thermal load is to cause mostly shearing deformations at the crack tip. For two configurations, a horizontal crack (normal to the heat flow direction) and a vertical crack (parallel to the heat flow direction), it is shown that increasing the adhesive thickness results in steady-state and maximum transient strain-energy release rates and stress-intensity factors of smaller magnitudes. It is also found that the ratio of mode I to mode II stressintensity factors for the vertical crack is larger than the one for the horizontal crack.