A comparison of the influence of nonlinear and linear creep on the behaviour of FRP-bonded metallic beams at warm temperatures

This study investigates whether it is necessary to consider nonlinear (rather than linear) adhesive viscoelasticity when considering the behaviour of an FRP-bonded metallic beam at warm service temperatures (25 °C, 30 °C and 40 °C). The paper presents finite element analyses that compare effects linear creep in bonded joint for two different FRP-strengthened beams (steel cast-iron). modelling work incorporates a viscoelastic constitutive model determined using dynamic mechanical analyser commonly used ambient cure structural epoxy adhesive. strengthening was characterised time-temperature superposition combined with parallel rheological framework model. found incorporating only leads slightly larger slip (maximum 1.0% after 1 year) lower CFRP axial stress 2.4% year), compared equivalent creep. has limited impact on performance cases studied. In most cases, simpler sufficient analyse environment.