Fatigue Performance of Two Structural Adhesives

The fatigue performance of two toughened epoxy adhesives suitable for use in heavy structural engineering is assessed using a purpose-built fatigue rig. One adhesive is of the single-part, hot-cure type and the other is a two-part, cold-cure system. It is found that the single-part adhesive performs better than the two-part adhesive in fatigue even though the latter has the higher fracture toughness. Crack growth rates in both adhesives are found to satisfy the Paris Law as closely as any other crack growth model, and no dependence is found on the frequency of load cycling in the range studied (0.5Hz-5Hz). The fatigue performance of both adhesives is very promising for their likely uses in large-scale structures.