Cyclic variation of stress as well as environmental humidity causes an increase of creep. In this part of the present series, the prediction formulae presented in the original BP model are now adapted to the present improved creep prediction model. The increase of creep due to stress cycling is described as a deviation from the prediction according to the principle of superposition, and therefore is a non-linear phenomenon. The increase of creep due to humidity cycling is partially formulated on the basis of diffusion theory considerations. Comparisons with test data show an acceptable agreement.
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