Modelling of the coupled effect of plastic damage and creep damage in Nimonic 80a

A review of the effect of prior inelastic deformation on high temperature mechanical response of engineering alloys

“…(15) provides a nonlinear differential equation with respect to the creep damage tensor Ω Ω Ω C and takes prior plastic deformation into account. Using this phenomenological model, reasonable agreement with the data in [14] for Nimonic 80A was obtained in [33]. Figure 22 shows the comparisons between modelling and experimental results.…”

“…Figure 22 shows the comparisons between modelling and experimental results. Note that in [33] prior deformation is seen as a factor introducing damage. Therefore only the enhancing effect of prior deformation on creep discussed in Section 2.…”

“…No extension to multi-axial creep deformation was presented. Murakami et al [33] proposed a numerical scheme to investigate coupled plastic and creep damage. They assumed that the plastic damage and subsequent creep damage occur at grain boundaries through cavity growth and the overall damage can be interpreted as an internal state variable representing the area density of the cavities.…”

“…Therefore only the enhancing effect of prior deformation on creep discussed in Section 2. • C where experimental and predicted curves are adapted from [14] and [33], respectively.…”

“…To quantify the evolution of creep damage, Ω Ω Ω C , based on metallurgical observations on creep damage processes (see, e.g., [34]), it was assumed in [33] that creep damage is characterised by the formation of plane cavities on the grain boundaries perpendicular to the maximum principal stress direction. The creep damage tensor is governed bẏ…”