Other Models of Behaviour:
The more complex real behaviours can generally be reproduced with sufficient accuracy by means of diverse combinations of the three simplest elements: spring, friction plane and dashpot.
Model of Shofield and Scott Blair :
This model is capable of representing the temporary evolution of the typical strain of many materials. After an elastic strain OA represented by a spring, a primary reversible yield AB takes place under unloading (visco-elastic behaviour). Starting from t1 a secondary yield BE with permanent strain in unloading is developed.