
Modelling fatigue of bone cement 313
creep equations. If the desired form of creep equation is not available within
the application, there is frequently a creep-speci c user subroutine that can
be used to incorporate a custom creep equation into the simulation. An
example of an explicit creep equation that has been used in several studies
is the following equation relating equivalent creep strain,
to accumu-
lated cycles, n, and peak von Mises stress, σ
vm
per cycle, rst proposed by
Verdonschot and Huiskes (1995):
e
063
[10.8]
Combining dynamic creep with a damage accumulation ...