A mathematical model to predict the stress–strain behavior of fibrous concrete composites
under random cyclic compressive loadings is developed. The envelope
unloading strain is used as an index of load history, while the plastic strain and
reloading strain are predicted as functions of the envelope unloading strain for both
full and partial unloading and reloading. The model is independent of the expression
used for the envelope curve. Comparison with cyclic data shows good agreement.
The model can be used for completely random loadings, in both the pre–peak and
post–peak ranges. It is suitable for both plain and fibrous concrete composites. The
model has been built using MATLAB language computer program facilitating the
advanced mathematical
difficulties of solving and differentiating complex expressions.
In this paper, the monotonic stress–strain curves of Al-Sulayfani model [1] for fibrous
concrete had been adopted.